60 results on '"Brett G. Jeffrey"'
Search Results
2. Photoreceptor degeneration in ABCA4-associated retinopathy and its genetic correlates
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Maximilian Pfau, Catherine A. Cukras, Laryssa A. Huryn, Wadih M. Zein, Ehsan Ullah, Marisa P. Boyle, Amy Turriff, Michelle A. Chen, Aarti S. Hinduja, Hermann E.A. Siebel, Robert B. Hufnagel, Brett G. Jeffrey, and Brian P. Brooks
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Ophthalmology ,Medicine - Abstract
BACKGROUND Outcome measures sensitive to disease progression are needed for ATP-binding cassette, sub-family A, member 4–associated (ABCA4-associated) retinopathy. We aimed to quantify ellipsoid zone (EZ) loss and photoreceptor degeneration beyond EZ-loss in ABCA4-associated retinopathy and investigate associations between photoreceptor degeneration, genotype, and age.METHODS We analyzed 132 eyes from 66 patients (of 67 enrolled) with molecularly confirmed ABCA4-associated retinopathy from a prospective natural history study with a median [IQR] follow-up of 4.2 years [3.1, 5.1]. Longitudinal spectral-domain optical coherence tomography volume scans (37 B-scans, 30° × 15°) were segmented using a deep learning (DL) approach. For genotype-phenotype analysis, a model of ABCA4 variants was applied with the age of criterion EZ-loss (6.25 mm2) as the dependent variable.RESULTS Patients exhibited an average (square-root-transformed) EZ-loss progression rate of [95% CI] 0.09 mm/y [0.06, 0.11]. Outer nuclear layer (ONL) thinning extended beyond the area of EZ-loss. The average distance from the EZ-loss boundary to normalization of ONL thickness (to ±2 z score units) was 3.20° [2.53, 3.87]. Inner segment (IS) and outer segment (OS) thinning was less pronounced, with an average distance from the EZ-loss boundary to layer thickness normalization of 1.20° [0.91, 1.48] for the IS and 0.60° [0.49, 0.72] for the OS. An additive model of allele severity explained 52.7% of variability in the age of criterion EZ-loss.CONCLUSION Patients with ABCA4-associated retinopathy exhibited significant alterations of photoreceptors outside of EZ-loss. DL-based analysis of photoreceptor laminae may help monitor disease progression and estimate the severity of ABCA4 variants.TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT01736293.FUNDING National Eye Institute Intramural Research Program and German Research Foundation grant PF950/1-1.
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- 2022
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3. Clinical Phenotypes of CDHR1-Associated Retinal Dystrophies
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Volha V. Malechka, Catherine A. Cukras, Emily Y. Chew, Yuri V. Sergeev, Delphine Blain, Brett G. Jeffrey, Ehsan Ullah, Robert B. Hufnagel, Brian P. Brooks, Laryssa A. Huryn, and Wadih M. Zein
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CDHR1 ,retinal dystrophy ,autosomal recessive retinal dystrophies ,Genetics ,QH426-470 - Abstract
The retinal dystrophy phenotype associated with CDHR1 retinopathy is clinically heterogenous. In this study, we describe the clinical and molecular findings of a retinal dystrophy cohort (10 patients) attributed to autosomal recessive CDHR1 and report novel variants in populations not previously identified with CDHR1-related retinopathy. Seven patients had evaluations covering at least a three-year period. The mean age of individuals at first symptoms was 36 ± 8.5 years (range 5–45 years). Visual acuity at the last visit ranged from 20/20 to 20/2000 (mean LogMAR 0.8 or 20/125). Three clinical subgroups were identified: rod–cone dystrophy (RCD), cone–rod dystrophy (CRD), and maculopathy. Extinguished scotopic electroretinography responses were noted in the RCD patients. Macular involvement was noted in all patients and documented on color fundus photography, fundus autofluorescence, and optical coherence tomography. Notable asymmetry of the degree of macular atrophy was present in two patients. The possible association between CDHR1 variants and clinical findings was predicted using molecular modeling.
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- 2022
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4. Persistent Dark Cones in Oligocone Trichromacy Revealed by Multimodal Adaptive Optics Ophthalmoscopy
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Joanne Li, Tao Liu, Oliver J. Flynn, Amy Turriff, Zhuolin Liu, Ehsan Ullah, Jianfei Liu, Alfredo Dubra, Mary A. Johnson, Brian P. Brooks, Robert B. Hufnagel, Daniel X. Hammer, Laryssa A. Huryn, Brett G. Jeffrey, and Johnny Tam
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adaptive optics ,scanning laser ophthalmoscopy ,optical coherence tomography ,dark cones ,visual function ,color vision ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Dark cone photoreceptors, defined as those with diminished or absent reflectivity when observed with adaptive optics (AO) ophthalmoscopy, are increasingly reported in retinal disorders. However, their structural and functional impact remain unclear. Here, we report a 3-year longitudinal study on a patient with oligocone trichromacy (OT) who presented with persistent, widespread dark cones within and near the macula. Diminished electroretinogram (ERG) cone but normal ERG rod responses together with normal color vision confirmed the OT diagnosis. In addition, the patient had normal to near normal visual acuity and retinal sensitivity. Occasional dark gaps in the photoreceptor layer were observed on optical coherence tomography, in agreement with reflectance AO scanning light ophthalmoscopy, which revealed that over 50% of the cones in the fovea were dark, increasing to 74% at 10° eccentricity. In addition, the cone density was 78% lower than normal histologic value at the fovea, and 20–40% lower at eccentricities of 5–15°. Interestingly, color vision testing was near normal at locations where cones were predominantly dark. These findings illustrate how a retina with predominant dark cones that persist over at least 3 years can support near normal central retinal function. Furthermore, this study adds to the growing evidence that cones can continue to survive under non-ideal conditions.
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- 2021
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5. Dark Adaptation and Its Role in Age-Related Macular Degeneration
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Archana K. Nigalye, Kristina Hess, Shrinivas J. Pundlik, Brett G. Jeffrey, Catherine A. Cukras, and Deeba Husain
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dark adaptation (DA) ,phototransduction ,cone-rod break (CRB) ,rod-intercept time (RIT) ,age-related macular degeneration (AMD) ,subretinal drusenoid deposits (SDD) ,Medicine - Abstract
Dark adaptation (DA) refers to the slow recovery of visual sensitivity in darkness following exposure to intense or prolonged illumination, which bleaches a significant amount of the rhodopsin. This natural process also offers an opportunity to understand cellular function in the outer retina and evaluate for presence of disease. How our eyes adapt to darkness can be a key indicator of retinal health, which can be altered in the presence of certain diseases, such as age-related macular degeneration (AMD). A specific focus on clinical aspects of DA measurement and its significance to furthering our understanding of AMD has revealed essential findings underlying the pathobiology of the disease. The process of dark adaptation involves phototransduction taking place mainly between the photoreceptor outer segments and the retinal pigment epithelial (RPE) layer. DA occurs over a large range of luminance and is modulated by both cone and rod photoreceptors. In the photopic ranges, rods are saturated and cone cells adapt to the high luminance levels. However, under scotopic ranges, cones are unable to respond to the dim luminance and rods modulate the responses to lower levels of light as they can respond to even a single photon. Since the cone visual cycle is also based on the Muller cells, measuring the impairment in rod-based dark adaptation is thought to be particularly relevant to diseases such as AMD, which involves both photoreceptors and RPE. Dark adaptation parameters are metrics derived from curve-fitting dark adaptation sensitivities over time and can represent specific cellular function. Parameters such as the cone-rod break (CRB) and rod intercept time (RIT) are particularly sensitive to changes in the outer retina. There is some structural and functional continuum between normal aging and the AMD pathology. Many studies have shown an increase of the rod intercept time (RIT), i.e., delays in rod-mediated DA in AMD patients with increasing disease severity determined by increased drusen grade, pigment changes and the presence of subretinal drusenoid deposits (SDD) and association with certain morphological features in the peripheral retina. Specifications of spatial testing location, repeatability of the testing, ease and availability of the testing device in clinical settings, and test duration in elderly population are also important. We provide a detailed overview in light of all these factors.
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- 2022
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6. Photoreceptor and Retinal Pigment Epithelium Relationships in Eyes With Vitelliform Macular Dystrophy Revealed by Multimodal Adaptive Optics Imaging
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Tao Liu, Nancy Aguilera, Andrew J. Bower, Joanne Li, Ehsan Ullah, Alfredo Dubra, Catherine Cukras, Brian P. Brooks, Brett G. Jeffrey, Robert B. Hufnagel, Laryssa A. Huryn, Wadih M. Zein, and Johnny Tam
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Extracellular Matrix Proteins ,Optics and Photonics ,Retinal Cone Photoreceptor Cells ,Humans ,Proteoglycans ,General Medicine ,Retinal Pigment Epithelium ,Bestrophins ,Eye Proteins ,Tomography, Optical Coherence ,Vitelliform Macular Dystrophy - Abstract
To assess the structure of cone photoreceptors and retinal pigment epithelial (RPE) cells in vitelliform macular dystrophy (VMD) arising from various genetic etiologies.Multimodal adaptive optics (AO) imaging was performed in 11 patients with VMD using a custom-assembled instrument. Non-confocal split detection and AO-enhanced indocyanine green were used to visualize the cone photoreceptor and RPE mosaics, respectively. Cone and RPE densities were measured and compared across BEST1-, PRPH2-, IMPG1-, and IMPG2-related VMD.Within macular lesions associated with VMD, both cone and RPE densities were reduced below normal, to 37% of normal cone density (eccentricity 0.2 mm) and to 8.4% of normal RPE density (eccentricity 0.5 mm). Outside of lesions, cone and RPE densities were slightly reduced (both to 92% of normal values), but with high degree of variability in the individual measurements. Comparison of juxtalesional cone and RPE measurements (1 mm from the lesion edge) revealed significant differences in RPE density across the four genes (P0.05). Overall, cones were affected to a greater extent than RPE in patients with IMPG1 and IMPG2 pathogenic variants, but RPE was affected more than cones in BEST1 and PRPH2 VMD. This trend was observed even in contralateral eyes from a subset of five patients who presented with macular lesions in only one eye.Assessment of cones and RPE in retinal locations outside of the macular lesions reveals a pattern of cone and RPE disruption that appears to be gene dependent in VMD. These findings provide insight into the cellular pathogenesis of disease in VMD.
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- 2022
7. Scotopic Contour Deformation Detection Reveals Early Rod Dysfunction in Age-Related Macular Degeneration With and Without Reticular Pseudodrusen
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Brett G. Jeffrey, Oliver J. Flynn, Laryssa A. Huryn, Maximilian Pfau, and Catherine A. Cukras
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Macular Degeneration ,Humans ,Retinal Drusen ,Fluorescein Angiography ,Retina ,Tomography, Optical Coherence - Abstract
The purpose of this study was to investigate scotopic contour deformation detection (sCDD), and its structural determinants, in participants with intermediate age-related macular degeneration (iAMD) with or without reticular pseudodrusen (RPD).Forty-one participants (aged 58-89 years), including 9 with iAMD and RPD, 16 with iAMD only, and 16 controls, underwent functional testing. The sCDD was evaluated with radial frequency arcs presented at 4 loci: ±4 degrees and 8 degrees vertical eccentricity. Scotopic thresholds and dark adaptation (DA) were measured at the same loci. Retinal layers of spectral domain optical coherence tomography (SD-OCT) volume scans were segmented. To establish the concurrent validity of the functional test, we evaluated the fraction of variability in sCDD thresholds explained by SD-OCT data.The iAMD group had significantly worse sCDD thresholds compared with controls (8 degrees inferior retina: P = 0.004 and the 4 degrees loci: P0.02 for both). Elevated sCDD thresholds were observed in iAMD and RPD eyes at loci with normal scotopic thresholds; the opposite was rarely encountered. Elevated sCDD thresholds were also observed in iAMD eyes with normal DA. Elevated sCDD thresholds were associated with increased age and presence of late AMD in the fellow eye. The optimal machine learning model predicted 16% of variability (cross-validated R2) in sCDD thresholds at 8 degrees.A novel scotopic contour deformation task can provide unique information about rod dysfunction in participants with iAMD and RPD not observed with structural and other functional assessments. Rod dysfunction observed with scotopic contour deformation testing was associated with factors linked to risk of AMD progression.
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- 2022
8. Clinical Phenotypes of
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Volha V, Malechka, Catherine A, Cukras, Emily Y, Chew, Yuri V, Sergeev, Delphine, Blain, Brett G, Jeffrey, Ehsan, Ullah, Robert B, Hufnagel, Brian P, Brooks, Laryssa A, Huryn, and Wadih M, Zein
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Phenotype ,Mutation ,Retinal Dystrophies ,Electroretinography ,Cadherin Related Proteins ,Humans ,Nerve Tissue Proteins ,Cadherins ,Cone-Rod Dystrophies - Abstract
The retinal dystrophy phenotype associated with
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- 2022
9. Rituximab for autoimmune retinopathy: Results of a Phase I/II clinical trial
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Patti Sherry, Karen R Armbrust, Brett G. Jeffrey, Austin R. Fox, and H. Nida Sen
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,autoimmunity ,Disease ,medicine.disease ,Autoimmune retinopathy ,Clinical trial ,Ophthalmology ,rituximab ,Quality of life ,lcsh:Ophthalmology ,lcsh:RE1-994 ,Internal medicine ,retinal degeneration ,visual fields ,Medicine ,Rituximab ,Original Article ,electroretinography ,business ,Prospective cohort study ,Adverse effect ,Electroretinography ,medicine.drug - Abstract
PURPOSE: This prospective study evaluates whether rituximab is a safe and potentially effective treatment for nonparaneoplastic autoimmune retinopathy (npAIR). MATERIALS AND METHODS: Five npAIR patients were enrolled in a Phase I/II, prospective, nonrandomized, open-label, single-center study. All patients received a cycle of 1000 mg intravenous rituximab at weeks 0 and 2, with a second cycle of rituximab 6 to 9 months later. Clinical evaluation was performed at baseline, 6 and 12 weeks after each rituximab cycle, and then every 3 months for a total duration of 18 months. The primary outcome for this study was treatment success based on visual field and full-field electroretinography at 6 months. The secondary outcomes included treatment success at months 12 and 18, drug-related adverse events, changes in visual symptoms, and changes in quality of life. RESULTS: Two patients met criteria for treatment success: one based solely on electroretinography and the other based solely on visual field area, but treatment success was not sustained. Clinical response over the course of the 18-month study showed disease stabilization in three patients and treatment failure in two patients. There were no severe drug-related adverse events. CONCLUSION: This is the first clinical trial prospectively evaluating the effect of rituximab in npAIR and, although rituximab was well tolerated, there was no clear-cut clinical improvement conferred by B cell depletion with rituximab.
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- 2021
10. ISCEV Standard for full-field clinical electroretinography (2022 update)
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Anthony G. Robson, Laura J. Frishman, John Grigg, Ruth Hamilton, Brett G. Jeffrey, Mineo Kondo, Shiying Li, and Daphne L. McCulloch
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Ophthalmology ,Physiology (medical) ,Electroretinography ,Humans ,Sensory Systems ,Photic Stimulation ,Retina ,Societies, Medical ,Vision, Ocular - Abstract
The full-field electroretinogram (ERG) is a mass electrophysiological response to diffuse flashes of light and is used widely to assess generalized retinal function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV), presents an updated and revised ISCEV Standard for clinical ERG testing. Minimum protocols for basic ERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis, monitoring and inter-laboratory comparisons, while also responding to evolving clinical practices and technology. The main changes in this updated ISCEV Standard for clinical ERGs include specifying that ERGs may meet the Standard without mydriasis, providing stimuli adequately compensate for non-dilated pupils. There is more detail about analysis of dark-adapted oscillatory potentials (OPs) and the document format has been updated and supplementary content reduced. There is a more detailed review of the origins of the major ERG components. Several tests previously tabulated as additional ERG protocols are now cited as published ISCEV extended protocols. A non-standard abbreviated ERG protocol is described, for use when patient age, compliance or other circumstances preclude ISCEV Standard ERG testing.
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- 2022
11. Deep Learning-Based Modeling of the Dark Adaptation Curve for Robust Parameter Estimation
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Tharindu, De Silva, Kristina, Hess, Peyton, Grisso, Alisa T, Thavikulwat, Henry, Wiley, Tiarnan D L, Keenan, Emily Y, Chew, Brett G, Jeffrey, and Catherine A, Cukras
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Macular Degeneration ,Ophthalmology ,Deep Learning ,Visual Acuity ,Biomedical Engineering ,Humans ,Dark Adaptation - Abstract
This study investigates deep-learning (DL) sequence modeling techniques to reliably fit dark adaptation (DA) curves and estimate their key parameters in patients with age-related macular degeneration (AMD) to improve robustness and curve predictions.A long-short-term memory autoencoder was used as the DL method to model the DA curve. The performance was compared against the classical nonlinear regression method using goodness-of-fit and repeatability metrics. Experiments were performed to predict the latter portion of the curve using data from early measurements. The prediction accuracy was quantified as the rod intercept time (RIT) prediction error between predicted and actual curves.The two models had comparable goodness-of-fit measures, with root mean squared error (RMSE; SD) = 0.11 (0.04) log-units (LU) for the classical model and RMSE = 0.13 (0.06) LU for the DL model. Repeatability of the curve fits evaluated after introduction of random perturbations, and after performing repeated testing, demonstrated superiority of the DL method, especially among parameters related to cone decay. The DL method exhibited superior ability to predict the curve and RIT using points prior to -2 LU, with 3.1 ± 3.1 minutes RIT prediction error, compared to 19.1 ± 18.6 minutes RIT error for the classical method.The parameters obtained from the DL method demonstrated superior robustness as well as predictability of the curve. These could provide important advances in using multiple DA curve parameters to characterize AMD severity.Dark adaptation is an important functional measure in studies of AMD and curve modeling using DL methods can lead to improved clinical trial end points.
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- 2022
12. Persistent Dark Cones in Oligocone Trichromacy Revealed by Multimodal Adaptive Optics Ophthalmoscopy
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Joanne Li, Amy Turriff, Ehsan Ullah, Jianfei Liu, Laryssa A. Huryn, Daniel X. Hammer, Robert B. Hufnagel, Tao Liu, Mary A. Johnson, Johnny Tam, Oliver J Flynn, Alfredo Dubra, Brian P. Brooks, Zhuolin Liu, and Brett G. Jeffrey
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0301 basic medicine ,medicine.medical_specialty ,Aging ,Retinal Disorder ,genetic structures ,Color vision ,Cognitive Neuroscience ,scanning laser ophthalmoscopy ,Oligocone trichromacy ,lcsh:RC321-571 ,adaptive optics ,Ophthalmoscopy ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,dark cones ,Ophthalmology ,oligocone trichromacy ,medicine ,visual function ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Original Research ,Physics ,Retina ,optical coherence tomography ,medicine.diagnostic_test ,Retinal ,eye diseases ,Scanning laser ophthalmoscopy ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,color vision ,030221 ophthalmology & optometry ,sense organs ,Erg ,pde6h ,Neuroscience - Abstract
Dark cone photoreceptors, defined as those with diminished or absent reflectivity when observed with adaptive optics (AO) ophthalmoscopy, are increasingly reported in retinal disorders. However, their structural and functional impact remain unclear. Here, we report a 3-year longitudinal study on a patient with oligocone trichromacy (OT) who presented with persistent, widespread dark cones within and near the macula. Diminished electroretinogram (ERG) cone but normal ERG rod responses together with normal color vision confirmed the OT diagnosis. In addition, the patient had normal to near normal visual acuity and retinal sensitivity. Occasional dark gaps in the photoreceptor layer were observed on optical coherence tomography, in agreement with reflectance AO scanning light ophthalmoscopy, which revealed that over 50% of the cones in the fovea were dark, increasing to 74% at 10° eccentricity. In addition, the cone density was 78% lower than normal histologic value at the fovea, and 20–40% lower at eccentricities of 5–15°. Interestingly, color vision testing was near normal at locations where cones were predominantly dark. These findings illustrate how a retina with predominant dark cones that persist over at least 3 years can support near normal central retinal function. Furthermore, this study adds to the growing evidence that cones can continue to survive under non-ideal conditions.
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- 2020
13. Repeatability of Scotopic Sensitivity and Dark Adaptation Using a Medmont Dark-Adapted Chromatic Perimeter in Age-related Macular Degeneration
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Durin Yesmin Uddin, Emily Y. Chew, Catherine A Cukras, Wai T. Wong, Tiarnan D L Keenan, Brett G. Jeffrey, Oliver J Flynn, and Henry E. Wiley
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0301 basic medicine ,medicine.medical_specialty ,retina ,Fovea Centralis ,genetic structures ,Biomedical Engineering ,Adaptation (eye) ,Dark Adaptation ,Article ,Perimeter ,03 medical and health sciences ,Macular Degeneration ,0302 clinical medicine ,Ophthalmology ,scotopic sensitivities ,medicine ,Humans ,Scotopic sensitivity ,Scotopic vision ,Chromatic scale ,repeatability ,age-related macular degeneration ,Mathematics ,Aged ,Aged, 80 and over ,Repeatability ,Macular degeneration ,medicine.disease ,Dark-adapted ,030104 developmental biology ,030221 ophthalmology & optometry ,Retinal Cone Photoreceptor Cells ,sense organs - Abstract
Purpose Functional studies of rods in age-related macular degeneration using the Medmont Dark-Adapted Chromatic Perimeter (DACP) have demonstrated impairments in scotopic sensitivities and dark adaptation (DA). We investigated the intersession repeatability of scotopic sensitivity and DA parameters including the rod intercept time recorded from the Medmont DACP. Methods Scotopic thresholds (14 test points) and DA using a 30% photobleach (eight test points) were measured on two separate days from participants 50 years of age or older with a range of age-related macular degeneration severity at loci superior and inferior to the fovea. Repeatability coefficients were calculated for prebleach scotopic sensitivity, and for DA parameters including rod intercept time. Results Twelve participants (mean age, 79.7 ± 8.1 years) repeated Medmont DACP testing within 50 days. Repeatability coefficients for prebleach scotopic sensitivity to long wavelength (red, 625 nm) and short wavelength (cyan, 505 nm) were 5.9 dB and 7.2 dB, respectively. The DA curve-derived repeatability coefficients for cone threshold was 3.9 dB, final threshold 5.3 dB, with an R value of 0.075 decades/min, rod intercept time 7.6 minutes, and RITslope 0.54 min/degree. Conclusions This study establishes repeatability coefficients for scotopic thresholds and multiple DA parameters obtained with the Medmont DACP in patients with age-related macular degeneration. These repeatability coefficients will serve as the basis for determining clinically meaningful change in rod function in future clinical trials. Translational relevance Measures of repeatability parameters of scotopic thresholds and DA are essential to the accurate interpretation of results in future studies and trials using these measures.
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- 2020
14. Reproducibility of Full-field Electroretinogram Measurements in Birdshot Chorioretinopathy Patients: An Intra- and Inter-visit Analysis
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Maggie M Wei, Jared E. Knickelbein, Shuk Kei Cheng, Natasha Kesav, Brett G. Jeffrey, Susan Vitale, and H. Nida Sen
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Adult ,Male ,medicine.medical_specialty ,genetic structures ,Dark Adaptation ,Article ,Retina ,03 medical and health sciences ,0302 clinical medicine ,Ophthalmology ,Electroretinography ,Humans ,Immunology and Allergy ,Medicine ,Fluorescein Angiography ,Aged ,Observer Variation ,030203 arthritis & rheumatology ,Reproducibility ,medicine.diagnostic_test ,business.industry ,Birdshot Chorioretinopathy ,Reproducibility of Results ,Repeatability ,Middle Aged ,medicine.disease ,Birdshot chorioretinopathy ,eye diseases ,Confidence interval ,030221 ophthalmology & optometry ,sense organs ,business ,Erg ,Jackknife resampling ,Photic Stimulation ,Photopic vision - Abstract
Purpose: Aims to determine the variability of ffERG measurements in patients with clinically stable birdshot chorioretinopathy (BCR). Methods: Repeatability coefficients (RC) of ffERG amplitudes and implicit times were calculated from 11 BCR patients. Jackknife resampling estimated 95% confidence intervals of each ERG parameter���s RC and the percentage change explained by variability alone was calculated. Results: Intra-visit variability in ffERG parameters was lower than inter-visit. Intravisit RCs demonstrated that for intravisit ERG testing, there was less than 30% variation in ERG amplitude for most parameters. For inter-visit ERG testing, a greater than 40% reduction in ERG amplitude may be clinically meaningful for 6 of 8 ERG parameters. Photopic single flash responses have Conclusions: A 40% reduction in ERG amplitude and/or a delay of >2 msec in the photopic single flash response may be suitable criteria for meaningful change in BCR patients.
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- 2020
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15. ISCEV extended protocol for derivation and analysis of the strong flash rod-isolated ERG a-wave
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Mitchell Brigell, Omar A. Mahroo, Brett G. Jeffrey, and Radouil Tzekov
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Internationality ,genetic structures ,Light ,Dark Adaptation ,Luminance ,Optics ,Clinical Protocols ,Retinal Rod Photoreceptor Cells ,Physiology (medical) ,medicine ,Electroretinography ,Humans ,Full field erg ,Societies, Medical ,Vision, Ocular ,Physics ,medicine.diagnostic_test ,business.industry ,eye diseases ,Sensory Systems ,Electrophysiology ,Ophthalmology ,Rod Photoreceptors ,sense organs ,business ,Erg ,Photic Stimulation ,Photopic vision ,Visual phototransduction - Abstract
The International Society for the Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum set of tests, but encourages the use of additional protocols for clinical ERG testing. This extended protocol describes recording methods and derivations that will allow analysis of rod-driven components of the dark-adapted (DA) strong flash ERG a-wave, more closely related to rod phototransduction than ISCEV standard DA ERGs. The method involves recording ERGs to a flash strength equivalent to 30 cd s m2 under conditions of dark adaptation and additionally to the same stimulus following light adaptation (LA) and in the presence of a standard photopic background luminance of 30 cd m−2. The isolated rod-driven ERG a-wave is derived by subtracting the LA response from the DA ERG. The method is likely to be of value in the characterization of retinal disorders which affect rod quantal catch, diseases that affect the dynamics of any component of the activation phase of rod phototransduction, or those affecting total numbers of rod photoreceptors.
- Published
- 2019
16. ISCEV Standard for clinical electro-oculography (2017 update)
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Laura J. Frishman, Anthony G. Robson, Brett G. Jeffrey, Michael Bach, and Paul A Constable
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Retinal pigment epithelium (RPE) ,Eye Diseases ,Light ,genetic structures ,Computer science ,ISCEV Standards ,Light peak:dark trough ratio ,Retinal Pigment Epithelium ,Light adaptation ,03 medical and health sciences ,0302 clinical medicine ,Fast oscillation (FO) ,Arden ratio ,Physiology (medical) ,medicine ,Saccades ,Humans ,Vision, Ocular ,Protocol (science) ,Clinical electrophysiology ,Electro-oculogram (EOG) ,medicine.diagnostic_test ,Adaptation, Ocular ,Electrooculography ,Electro-oculography ,Sensory Systems ,eye diseases ,Electrophysiology ,Ophthalmology ,030221 ophthalmology & optometry ,Optometry ,sense organs ,Erratum ,030217 neurology & neurosurgery - Abstract
The clinical electro-oculogram (EOG) is an electrophysiological test of the outer retina and retinal pigment epithelium (RPE) in which changes in the electrical potential across the RPE are recorded during successive periods of dark and light adaptation. This document presents the 2017 EOG Standard from the International Society for Clinical Electrophysiology of Vision (ISCEV: www.iscev.org). This standard has been reorganized and updated to include an explanation of the mechanism of the EOG, but without substantive changes to the testing protocol from the previous version published in 2011. It describes methods for recording the EOG in clinical applications and gives detailed guidance on technical requirements, practical issues and reporting of results with the main clinical measure (the Arden ratio) now termed the light peak:dark trough ratio. The standard is intended to promote consistent quality of testing and reporting within and between clinical centers.
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- 2017
17. ISCEV extended protocol for the stimulus-response series for the dark-adapted full-field ERG b-wave
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Anthony G. Robson, Andre Messias, Brett G. Jeffrey, and Mary A. Johnson
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genetic structures ,Computer science ,Vision Disorders ,Dark Adaptation ,03 medical and health sciences ,0302 clinical medicine ,Clinical Protocols ,Retinal Diseases ,Retinal Rod Photoreceptor Cells ,Physiology (medical) ,medicine ,Electroretinography ,Humans ,Full field erg ,Societies, Medical ,medicine.diagnostic_test ,eye diseases ,Sensory Systems ,Stimulus response ,Dark-adapted ,Ophthalmology ,030221 ophthalmology & optometry ,sense organs ,Neuroscience ,030217 neurology & neurosurgery ,Photic Stimulation - Abstract
The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum protocol for clinical testing but encourages more extensive testing where appropriate. This ISCEV extended protocol describes an extension of the ISCEV full-field ERG standard, in which methods to record and evaluate the growth of the dark-adapted (DA) ERG b-wave with increasing stimulus energy are described. The flashes span a range that includes the weakest flash required to generate a reliable DA ERG b-wave and that required to generate a maximal b-wave amplitude. The DA ERG b-wave stimulus–response series (also known historically as the “intensity–response” or “luminance–response” series) can more comprehensively characterize generalized rod system function than the ISCEV standard ERG protocol and may be of diagnostic or prognostic value in disorders that cause generalized rod system dysfunction.
- Published
- 2019
18. Rituximab treatment for nonparaneoplastic autoimmune retinopathy
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H. Nida Sen, Austin Fox, Robert B. Nussenblatt, Brett G. Jeffrey, and Sarfaraz Hasni
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Ophthalmology ,business.industry ,Immunology ,medicine ,Rituximab ,General Medicine ,medicine.disease ,business ,Autoimmune retinopathy ,medicine.drug - Published
- 2015
19. One-year pilot study on the effects of nitisinone on melanin in patients with OCA-1B
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William A. Gahl, Bradley Power, Shosuke Ito, Brett G. Jeffrey, Angel Garced, Ramon Jauregui, Zaheer M. Valivullah, Shanna Bernstein, Supriya M. Menezes, Kazumasa Wakamatsu, Edythe Wiggs, Pei-Wen Chiang, Melissa A. Merideth, Wendy J. Introne, Brian P. Brooks, Denise Cunningham, Rhona M. Jack, David R. Adams, Maria Abraham, and Ramakrishna P. Alur
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Visual acuity ,Nitisinone ,Intraclass correlation ,Tyrosinase ,Melanin ,03 medical and health sciences ,0302 clinical medicine ,Ophthalmology ,Genetics ,Medicine ,In patient ,business.industry ,General Medicine ,medicine.disease ,Oculocutaneous albinism ,eye diseases ,030104 developmental biology ,030220 oncology & carcinogenesis ,Albinism ,sense organs ,medicine.symptom ,Clinical Medicine ,business ,medicine.drug ,Genetic diseases - Abstract
BACKGROUND. Oculocutaneous albinism (OCA) results in reduced melanin synthesis, skin hypopigmentation, increased risk of UV-induced malignancy, and developmental eye abnormalities affecting vision. No treatments exist. We have shown that oral nitisinone increases ocular and fur pigmentation in a mouse model of one form of albinism, OCA-1B, due to hypomorphic mutations in the Tyrosinase gene. METHODS. In this open-label pilot study, 5 adult patients with OCA-1B established baseline measurements of iris, skin, and hair pigmentation and were treated over 12 months with 2 mg/d oral nitisinone. Changes in pigmentation and visual function were evaluated at 3-month intervals. RESULTS. The mean change in iris transillumination, a marker of melanin, from baseline was 1.0 ± 1.54 points, representing no change. The method of iris transillumination grading showed a high intergrader reliability (intraclass correlation coefficient ≥ 0.88 at each visit). The number of letters read (visual acuity) improved significantly at month 12 for both eyes (right eye, OD, mean 4.2 [95% CI, 0.3, 8.1], P = 0.04) and left eye (OS, 5 [1.0, 9.1], P = 0.003). Skin pigmentation on the inner bicep increased (M index increase = 1.72 [0.03, 3.41], P = 0.047). Finally, hair pigmentation increased by both reflectometry (M index [17.3 {4.4, 30.2}, P = 0.01]) and biochemically. CONCLUSION. Nitisinone did not result in an increase in iris melanin content but may increase hair and skin pigmentation in patients with OCA-1B. The iris transillumination grading scale used in this study proved robust, with potential for use in future clinical trials. TRIAL REGISTRATION. ClinicalTrials.gov NCT01838655. FUNDING. Intramural program of the National Eye Institute., Oral nitisinone may improve melanin pigmentation in patients with the OCA-1B form of albinism due to hypomorphic mutations in the tyrosinase gene.
- Published
- 2018
20. Analysis of Anatomic and Functional Measures in X-Linked Retinoschisis
- Author
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Brett G. Jeffrey, Catherine A Cukras, Paul A. Sieving, Laryssa A. Huryn, and Amy Turriff
- Subjects
0301 basic medicine ,Adult ,Male ,medicine.medical_specialty ,Visual acuity ,longitudinal ,genetic structures ,Adolescent ,Retinoschisis ,Visual Acuity ,030105 genetics & heredity ,Ophthalmology & Optometry ,Medical and Health Sciences ,Spearman's rank correlation coefficient ,Retina ,Correlation ,03 medical and health sciences ,0302 clinical medicine ,Ophthalmology ,Electroretinography ,Medicine ,Humans ,In patient ,Preschool ,Child ,Eye Proteins ,Tomography ,Aged ,medicine.diagnostic_test ,business.industry ,Biological Sciences ,Middle Aged ,medicine.disease ,eye diseases ,Optical Coherence ,natural history ,Child, Preschool ,030221 ophthalmology & optometry ,X-linked retinoschisis ,sense organs ,medicine.symptom ,Erratum ,business ,Erg ,Tomography, Optical Coherence - Abstract
Author(s): Cukras, Catherine A; Huryn, Laryssa A; Jeffrey, Brett G; Turriff, Amy; Sieving, Paul A | Abstract: PurposeTo examine the symmetry of structural and functional parameters between eyes in patients with X-linked retinoschisis (XLRS), as well as changes in visual acuity and electrophysiology over time.MethodsThis is a single-center observational study of 120 males with XLRS who were evaluated at the National Eye Institute. Examinations included best-corrected visual acuity for all participants, as well as ERG recording and optical coherence tomography (OCT) on a subset of participants. Statistical analyses were performed using nonparametric Spearman correlations and linear regression.ResultsOur analyses demonstrated a statistically significant correlation of structural and functional measures between the two eyes of XLRS patients for all parameters. OCT central macular thickness (n = 78; Spearman r = 0.83, P l 0.0001) and ERG b/a ratio (n = 78; Spearman r = 0.82, P l 0.0001) were the most strongly correlated between a participant's eyes, whereas visual acuity was less strongly correlated (n = 120; Spearman r = 0.47, P l 0.0001). Stability of visual acuity was observed with an average change of less than one letter (n = 74; OD -0.66 and OS -0.70 letters) in a mean follow-up time of 6.8 years. There was no statistically significant change in the ERG b/a ratio within eyes over time.ConclusionsAlthough a broad spectrum of clinical phenotypes is observed across individuals with XLRS, our study demonstrates a significant correlation of structural and functional findings between the two eyes and stability of measures of acuity and ERG parameters over time. These results highlight the utility of the fellow eye as a useful reference for monocular interventional trials.
- Published
- 2018
21. Retinal AAV8-RS1 Gene Therapy for X-Linked Retinoschisis: Initial Findings from a Phase I/IIa Trial by Intravitreal Delivery
- Author
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Sten Kjellstrom, Paul A. Sieving, Lisa L. Wei, Camasamudram Vijayasarathy, Yong Zeng, H. Nida Sen, Zhijian Wu, Henry E. Wiley, Brett G. Jeffrey, Peter Colosi, J. Fraser Wright, Suja Hiriyanna, Ronald A. Bush, Catherine A Cukras, Amy Turriff, Tae Kwon Park, Dario Marangoni, Lucia Ziccardi, Cukras, C, Wiley, He, Jeffrey, Bg, Sen, Hn, Turriff, A, Zeng, Y, Vijayasarathy, C, Marangoni, D, Ziccardi, L, Kjellstrom, S, Park, Tk, Hiriyanna, S, Wright, Jf, Colosi, P, Wu, Z, Bush, Ra, Wei, Ll, and Sieving, Pa.
- Subjects
Male ,0301 basic medicine ,Technology ,genetic structures ,Genetic enhancement ,Retinoschisin Protein ,Retinoschisis ,Eye ,Medical and Health Sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Drug Discovery ,Retinal detachment ,clinical trial ,Middle Aged ,Biological Sciences ,gene therapy ,AAV vector ,medicine.anatomical_structure ,Tolerability ,6.1 Pharmaceuticals ,Intravitreal Injections ,Molecular Medicine ,Female ,X-linked retinoschisis ,Biotechnology ,Adult ,medicine.medical_specialty ,Clinical Trials and Supportive Activities ,X-linked retinoschisi ,Retina ,ocular disease ,retinal disease ,Young Adult ,03 medical and health sciences ,Clinical Research ,Ophthalmology ,Genetics ,medicine ,Humans ,Eye Proteins ,Eye Disease and Disorders of Vision ,Molecular Biology ,Aged ,Pharmacology ,business.industry ,Neurosciences ,Evaluation of treatments and therapeutic interventions ,Retinal ,Genetic Therapy ,medicine.disease ,eye diseases ,Clinical trial ,030104 developmental biology ,chemistry ,Mutation ,030221 ophthalmology & optometry ,business - Abstract
This study evaluated the safety and tolerability of ocular RS1 adeno-associated virus (AAV8-RS1) gene augmentation therapy to the retina of participants with X-linked retinoschisis (XLRS). XLRS is a monogenic trait affecting only males, caused by mutations in the RS1 gene. Retinoschisin protein is secreted principally in the outer retina, and its absence results in retinal cavities, synaptic dysfunction, reduced visual acuity, and susceptibility to retinal detachment. This phase I/IIa single-center, prospective, open-label, three-dose-escalation clinical trial administered vector to nine participants with pathogenic RS1 mutations. The eye of each participant with worse acuity (≤63 letters; Snellen 20/63) received the AAV8-RS1 gene vector by intravitreal injection. Three participants were assigned to each of three dosage groups: 1e9 vector genomes (vg)/eye, 1e10 vg/eye, and 1e11 vg/eye. The investigational product was generally well tolerated in all but one individual. Ocular events included dose-related inflammation that resolved with topical and oral corticosteroids. Systemic antibodies against AAV8 increased in a dose-related fashion, but no antibodies against RS1 were observed. Retinal cavities closed transiently in one participant. Additional doses and immunosuppressive regimens are being explored to pursue evidence of safety and efficacy (ClinicalTrials.gov: NCT02317887).
- Published
- 2018
22. Diagnosis of Occult Melanoma Using Transient Receptor Potential Melastatin 1 (TRPM1) Autoantibody Testing
- Author
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Elizabeth A. Gamboa, Robert M. Duvoisin, Chi-Chao Chan, Brett G. Jeffrey, Catherine W. Morgans, Sunir J. Garg, H. Nida Sen, and Monica Dalal
- Subjects
Pathology ,medicine.medical_specialty ,genetic structures ,Axillary lymph nodes ,medicine.diagnostic_test ,business.industry ,Melanoma ,Autoantibody ,medicine.disease ,Fluorescein angiography ,Occult ,eye diseases ,Ophthalmology ,medicine.anatomical_structure ,medicine ,sense organs ,business ,TRPM1 ,Retinopathy ,Electroretinography - Abstract
Purpose To report the first case of melanoma-associated retinopathy (MAR) and underlying occult melanoma diagnosed based on the presence of serum transient receptor potential melastatin 1 (TRPM1) autoantibodies. Design Interventional case report with basic science correlation. Participants One patient with MAR. Intervention Testing for the presence of serum TRPM1 autoantibodies. Main Outcome Measures Diagnosis of an occult melanoma involving the axillary lymph nodes (unknown primary site) and MAR based on the presence of TRPM1 autoantibodies in the patient's serum. Results The patient's clinical exam was remarkable for mild intraocular inflammation in both eyes and retinal hemorrhages with an apparent choroidal neovascularization in the left eye, which was confirmed by fluorescein angiography and indocyanine green angiography testing. Humphrey visual field 30-2 SITA-fast (Humphrey Visual Field Analyzer, Carl Zeiss Meditec, Inc, Dublin, CA) demonstrated diffuse depression in both eyes out of proportion to the clinical exams, prompting electroretinography testing that revealed an electronegative response. Dark-adapted thresholds were markedly elevated and mediated by cones. Due to concern for MAR, a systemic work-up for melanoma was performed by the primary care physician that was unrevealing. Given our continued clinical suspicion for MAR, the patient's serum was sent for evaluation for TRPM1 autoantibodies. The patient's serum applied to normal human retina exhibited positivity in the inner nuclear layer. Application of the patient's serum to wild-type and TRPM1 knockout mouse retina revealed strongly labeled bipolar cells in the wild-type retina, but not in the TRPM1 knockout retina, indicating TRPM1-dependent immunoreactivity. The antigen was confirmed as TRPM1 by labeling of TRPM1-transfected human embryonic kidney 293 cells. Additional systemic work-up prompted by this finding resulted in identification of an occult metastatic melanoma involving the axillary lymph nodes with an unknown primary site. The patient underwent surgical excision of the occult melanoma without evidence of other sites of metastases. He also received intravenous immunoglobulin therapy and his vision has stabilized. Conclusions This is the first reported case of a melanoma-associated retinopathy diagnosed utilizing the innovative approach of testing for serum TRPM1 autoantibodies. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references.
- Published
- 2013
23. Ocular Phenotype of a Family with FAM161A-associated Retinal Degeneration
- Author
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Radha Ayyagari, Moreno Menghini, Shiri Soudry, Rafael C. Caruso, Mili Navani, Pauline Lee, Reema Syed, Brett G. Jeffrey, Jacque L. Duncan, Austin Roorda, G. Bhanuprakash Reddy, Pooja Biswas, Igor Kozak, and John R. Heckenlively
- Subjects
Retinal degeneration ,Proband ,Male ,Exome sequencing ,Pathology ,Visual acuity ,genetic structures ,DNA Mutational Analysis ,Visual Acuity ,Blindness ,Eye ,Ophthalmology & Optometry ,2.1 Biological and endogenous factors ,Exome ,Aetiology ,Tomography ,Genetics (clinical) ,medicine.diagnostic_test ,Retinal Degeneration ,Middle Aged ,Scanning laser ophthalmoscopy ,Pedigree ,Phenotype ,Codon, Nonsense ,Female ,medicine.symptom ,Erg ,Tomography, Optical Coherence ,Adult ,medicine.medical_specialty ,Biology ,Article ,Clinical Research ,Opthalmology and Optometry ,medicine ,Electroretinography ,Genetics ,Humans ,FAM161A ,Eye Proteins ,Codon ,Eye Disease and Disorders of Vision ,Aged ,Human Genome ,Neurosciences ,medicine.disease ,Ophthalmology ,Nonsense ,Optical Coherence ,Pediatrics, Perinatology and Child Health ,Visual Field Tests ,Visual Fields - Abstract
BackgroundCharacterization of retinal degeneration (RD) using high-resolution retinal imaging and exome sequencing may identify phenotypic features that correspond with specific genetic defects.Materials and methodsSix members from a non-consanguineous Indian family (three affected siblings, their asymptomatic parents and an asymptomatic child) were characterized clinically, using visual acuity, perimetry, full-field electroretinography (ERG), optical coherence tomography and cone structure as outcome measures. Cone photoreceptors were imaged in the proband using adaptive optics scanning laser ophthalmoscopy. The exome was captured using Nimblegen SeqCap EZ V3.0 probes and sequenced using lllumina HiSeq. Reads were mapped to reference hg19. Confirmation of variants and segregation analysis was performed using dideoxy sequencing.ResultsAnalysis of exome variants using exomeSuite identified five homozygous variants in four genes known to be associated with RD. Further analysis revealed a homozygous nonsense mutation, c.1105 C > T, p.Arg335Ter, in the FAM161A gene segregating with RD. Three additional variants were found to occur at high frequency. Affected members showed a range of disease severity beginning at different ages, but all developed severe visual field and outer retinal loss.ConclusionsExome analysis revealed a nonsense homozygous mutation in FAM161A segregating with RD with severe vision loss and a range of disease onset and progression. Loss of outer retinal structures demonstrated with high-resolution retinal imaging suggests FAM161A is important for normal photoreceptor structure and survival. Exome sequencing may identify causative genetic variants in autosomal recessive RD families when other genetic test strategies fail to identify a mutation.
- Published
- 2016
24. The Effects of Gender and Age on the Range of the Normal Human Electro-Oculogram
- Author
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Alisa T. Thavikulwat, Rafael C. Caruso, P. Lopez, and Brett G. Jeffrey
- Subjects
Adult ,Male ,medicine.medical_specialty ,genetic structures ,Adolescent ,Electro oculogram ,Dark Adaptation ,Retinal Pigment Epithelium ,Audiology ,Article ,Developmental psychology ,Age and gender ,Contrast Sensitivity ,Sex Factors ,Reference Values ,Physiology (medical) ,medicine ,Humans ,Child ,Aged ,Age Factors ,Pupil ,Middle Aged ,eye diseases ,Sensory Systems ,Healthy Volunteers ,Ophthalmology ,Electrooculography ,Clinical electrophysiology ,Female ,sense organs ,Psychology ,Photic Stimulation - Abstract
To define the normal ranges for the slow oscillations (SO) and fast oscillations (FO) of the electro-oculogram (EOG) recorded to International Society for Clinical Electrophysiology of Vision (ISCEV) standards. The effects of age and gender on the EOG ranges were examined.ISCEV standard SOs and FOs were recorded from 121 subjects (51 % male) aged from 7 to 72 years. Study variables for the SO were dark trough (DT) and light peak (LP) amplitudes (µV), times to DT and LP (min), and the Arden ratio (LP/DT amplitude). The FO was fit by a sine wave and peak-to-peak amplitude (µV), phase (°), and peak-to-trough (PT) ratios derived. The effects of age, gender and pupil size on EOG parameters were examined by multiple regression analysis.The average Arden ratio was 2.5. Arden ratio decreased with age at a rate of 0.13 per decade of age (R (2) = 0.14, P0.0001). The 5th percentile of the Arden ratio decreased from 2.0 to 1.7 between 10 and 60 years of age. Median time to LP was 9 min (interquartile range 8-9 min). Time to LP was age-dependent and increased by 2 min for subjects over 55 years of age compared with those less than 25 years. EOG amplitudes were greater in women than in men (P0.005). The average PT ratio was 1.18, which was not affected by age or gender. Time to reach the light trough of the FO was 40 s, which increased with age (1.1 s/decade). No correlation was observed between Arden ratio and PT ratio.The major strength of this study is the definition of the normal range and associated lower limits of ISCEV standard EOGs based on recordings from 121 subjects balanced by gender and spanning the 1st through 8th decades of life. Decreased Arden ratio and increased time to LP are associated with aging, which is likely due to the intricate mechanisms involved in generation of the light rise. Differences between the FO and SO with respect to the effects of aging are consistent with separate generation of these two EOG signals.
- Published
- 2015
25. Rod-mediated contour integration measured under scotopic conditions using radial frequency patterns
- Author
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Brett G. Jeffrey and Oliver J Flynn
- Subjects
Physics ,Ophthalmology ,Angular frequency ,Optics ,business.industry ,Scotopic vision ,business ,Methods of contour integration ,Sensory Systems - Published
- 2018
26. Methodological Insights for Randomized Clinical Trials of Retinitis Pigmentosa
- Author
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Brett G. Jeffrey and Brian P. Brooks
- Subjects
0301 basic medicine ,Pediatrics ,medicine.medical_specialty ,Valproic Acid ,Blindness ,business.industry ,MEDLINE ,medicine.disease ,law.invention ,03 medical and health sciences ,Ophthalmology ,030104 developmental biology ,0302 clinical medicine ,Randomized controlled trial ,law ,Retinitis pigmentosa ,030221 ophthalmology & optometry ,Medicine ,business ,medicine.drug - Published
- 2018
27. Characterization of Rod Function Phenotypes Across a Range of Age-Related Macular Degeneration Severities and Subretinal Drusenoid Deposits
- Author
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Oliver J Flynn, Brett G. Jeffrey, and Catherine A Cukras
- Subjects
Male ,medicine.medical_specialty ,genetic structures ,Fundus Oculi ,Visual Acuity ,subretinal drusenoid deposits ,Dark Adaptation ,Retinal Drusen ,AMD ,rod intercept time ,Drusen ,Biology ,Retina ,SDD ,scotopic thresholds ,Macular Degeneration ,03 medical and health sciences ,0302 clinical medicine ,Optical coherence tomography ,Retinal Rod Photoreceptor Cells ,Ophthalmology ,Age related ,medicine ,Humans ,Macula Lutea ,Scotopic vision ,Fluorescein Angiography ,age-related macular degeneration ,Aged ,Aged, 80 and over ,medicine.diagnostic_test ,Middle Aged ,Macular degeneration ,medicine.disease ,Phenotype ,eye diseases ,RIT ,Meridian (perimetry, visual field) ,medicine.anatomical_structure ,030221 ophthalmology & optometry ,Female ,sense organs ,Tomography, Optical Coherence ,030217 neurology & neurosurgery - Abstract
Purpose To examine spatial changes in rod-mediated function in relationship to local structural changes across the central retina in eyes with a spectrum of age-related macular degeneration (AMD) disease severity. Methods Participants were categorized into five AMD severity groups based on fundus features. Scotopic thresholds were measured at 14 loci spanning ±18° along the vertical meridian from one eye of each of 42 participants (mean = 71.7 ± 9.9 years). Following a 30% bleach, dark adaptation was measured at eight loci (±12°). Rod intercept time (RIT) was defined from the time to detect a −3.1 log cd/m2 stimulus. RITslope was defined from the linear fit of RIT with decreasing retinal eccentricity. The presence of subretinal drusenoid deposits (SDD), ellipsoid (EZ) band disruption, and drusen at the test loci was evaluated using optical coherence tomography. Results Scotopic thresholds indicated greater rod function loss in the macula, which correlated with increasing AMD group severity. RITslope, which captures the spatial change in the rate of dark adaptation, increased with AMD severity (P < 0.0001). Three rod function phenotypes emerged: RF1, normal rod function; RF2, normal scotopic thresholds but slowed dark adaptation; and RF3, elevated scotopic thresholds with slowed dark adaptation. Dark adaptation was slowed at all loci with SDD or EZ band disruption, and at 32% of loci with no local structural changes. Conclusions Three rod function phenotypes were defined from combined measurement of scotopic threshold and dark adaptation. Spatial changes in dark adaptation across the macula were captured with RITslope, which may be a useful outcome measure for functional studies of AMD.
- Published
- 2018
28. TRPM1 is required for the depolarizing light response in retinal ON-bipolar cells
- Author
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Robert M. Duvoisin, Steve M. Nelson, Brett G. Jeffrey, R. Lane Brown, J. Zhang, Neal S. Burke, and Catherine W. Morgans
- Subjects
Retinal Bipolar Cells ,Patch-Clamp Techniques ,genetic structures ,Light ,TRPM Cation Channels ,Mice, Transgenic ,Biology ,Mice ,chemistry.chemical_compound ,Electroretinography ,medicine ,Animals ,Patch clamp ,In Situ Hybridization ,Vision, Ocular ,Retina ,Multidisciplinary ,medicine.diagnostic_test ,Gene Expression Profiling ,Metabotropic glutamate receptor 6 ,Depolarization ,Retinal ,Dendrites ,Anatomy ,Biological Sciences ,Cell biology ,Light intensity ,medicine.anatomical_structure ,Microscopy, Fluorescence ,chemistry ,Inner nuclear layer ,sense organs ,Photoreceptor Cells, Vertebrate - Abstract
The ON pathway of the visual system, which detects increases in light intensity, is established at the first retinal synapse between photoreceptors and ON-bipolar cells. Photoreceptors hyperpolarize in response to light and reduce the rate of glutamate release, which in turn causes the depolarization of ON-bipolar cells. This ON-bipolar cell response is mediated by the metabotropic glutamate receptor, mGluR6, which controls the activity of a depolarizing current. Despite intensive research over the past two decades, the molecular identity of the channel that generates this depolarizing current has remained elusive. Here, we present evidence indicating that TRPM1 is necessary for the depolarizing light response of ON-bipolar cells, and further that TRPM1 is a component of the channel that generates this light response. Gene expression profiling revealed that TRPM1 is highly enriched in ON-bipolar cells. In situ hybridization experiments confirmed that TRPM1 mRNA is found in cells of the retinal inner nuclear layer, and immunofluorescent confocal microscopy showed that TRPM1 is localized in the dendrites of ON-bipolar cells in both mouse and macaque retina. The electroretinogram (ERG) of TRPM1-deficient (TRPM1 −/− ) mice had a normal a-wave, but no b-wave, indicating a loss of bipolar cell response. Finally, whole-cell patch-clamp recording from ON-bipolar cells in mouse retinal slices demonstrated that genetic deletion of TRPM1 abolished chemically simulated light responses from rod bipolar cells and dramatically altered the responses of cone ON-bipolar cells. Identification of TRPM1 as a mGluR6-coupled cation channel reveals a key step in vision, expands the role of the TRP channel family in sensory perception, and presents insights into the evolution of vertebrate vision.
- Published
- 2009
29. Visual development: neural basis and new assessment methods
- Author
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Brett G. Jeffrey and Martha Neuringer
- Subjects
Cerebral Cortex ,Fovea Centralis ,Docosahexaenoic Acids ,genetic structures ,business.industry ,Visual Acuity ,Infant ,eye diseases ,Biochemistry ,Visual function ,Task Performance and Analysis ,Pediatrics, Perinatology and Child Health ,Visual assessment ,Assessment methods ,Electroretinography ,Fatty Acids, Unsaturated ,Animals ,Humans ,Medicine ,Photoreceptor Cells ,business ,Beneficial effects ,Neuroscience ,Vision, Ocular ,Visual Cortex - Abstract
The strongest evidence for beneficial effects of long-chain polyunsaturated fatty acid (LCPUFA) supplementation comes from measures of visual development. In particular, two measures of visual function, the electroretinogram (ERG) and grating acuity, have provided the primary basis for the addition of LCPUFA to infant formulas. However, the neural mechanisms underlying dietary effects on these visual functions are not well understood. Furthermore, the influence of dietary LCPUFA on other aspects of visual development is largely unknown. Additional measures of visual function would help to clarify the extent and nature of the effects of LCPUFA on the developing visual system, and several new methods promise to provide more detailed information about the sites of these effects. A number of recent reviews have described methods for visual assessment and the effects of infant LCPUFA supplementation on visual development. Therefore, the following review will emphasize newer developments in infant visual assessment and in understanding the neural mechanisms that may underlie the effects of LCPUFA.
- Published
- 2003
30. Circular contour frequency in shape discrimination
- Author
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Brett G. Jeffrey, Yi-Zhong Wang, and Eileen E. Birch
- Subjects
genetic structures ,Geometry ,Deformation (meteorology) ,Discrimination, Psychological ,Optics ,Contour ,Orientation ,Modulation (music) ,Psychophysics ,Humans ,Physics ,Hyperacuity ,Angular frequency ,business.industry ,Orientation (computer vision) ,Threshold ,Shape ,Radius ,Viewing angle ,Sensory Systems ,Form Perception ,Ophthalmology ,Pattern Recognition, Visual ,Sensory Thresholds ,business - Abstract
Circular contour frequency (the number of radial cycles per degree of unmodulated contour length measured in degrees of viewing angle) is an important factor in determining the deformation threshold of radial frequency (RF) patterns. Radial deformation thresholds were closely matched at a given circular contour frequency regardless of RF or radius. Our results suggest that two separate mechanisms may be involved in determining radial deformation thresholds. First, for low RFs, our results support a model of shape discrimination in which global integration occurs across all modulation cycles of an RF pattern. Second, for higher RFs, our data suggest that threshold may be determined by visual integration only over a limited segment of the RF pattern.
- Published
- 2002
31. Retinal sensitivity loss in third-generation n-3 PUFA-deficient rats
- Author
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Harrison S. Weisinger, Drake C. Mitchell, Norman Salem, Richard S. Weisinger, Andrew J. Sinclair, Toru Moriguchi, Brett G. Jeffrey, and James A. Armitage
- Subjects
medicine.medical_specialty ,Time Factors ,Clinical chemistry ,Nutritional Status ,Stimulation ,Biology ,Models, Biological ,Biochemistry ,Retina ,chemistry.chemical_compound ,Internal medicine ,Fatty Acids, Omega-3 ,Electroretinography ,medicine ,Animals ,Ingestion ,Phospholipids ,Vision, Ocular ,chemistry.chemical_classification ,Fatty Acids ,Retinal Degeneration ,Organic Chemistry ,Retinal ,Cell Biology ,Dietary Fats ,Rats ,Endocrinology ,chemistry ,lipids (amino acids, peptides, and proteins) ,Arachidonic acid ,Docosapentaenoic acid ,Photic Stimulation ,Lipidology ,Polyunsaturated fatty acid - Abstract
A previous study conducted in guinea pigs suggested that ingestion of diets high in EPA and DHA may result in suboptimal retinal function. The aim of the present study was to evaluate retinal function in pigmented (Long-Evans) rats, raised to a third generation on diets that were either deficient in n-3 PUFA or adequate (with the addition of DHA). Electroretinographic assessment employed full-field white flash stimulation. Photoreceptor responses were evaluated in terms of peak amplitudes and implicit times (a-wave, b-wave), intensity-response functions (Naka-Rushton), and the parameters of a model of transduction (P3). Retinal phospholipid FA composition was measured by capillary GLC. DHA levels were reduced by 55% in n-3-deficient animals compared with the n-3-adequate group, whereas the levels of docosapentaenoic acid n-6 were 44 times higher in n-3-deficient animals. The level of arachidonic acid was marginally higher (12.8%) in n-6-adequate animals. The n-3-deficient animals exhibited significantly reduced retinal sensitivity (sigma and S values were both affected by 0.29 log units) and increased b-wave implicit times compared with those fed the n-3-adequate diet. These data suggest that n-3 PUFA are required for development of retinal sensitivity, more so than other indices of retinal function assessed by current methods, such as maximal response amplitude. However, the benefit for retinal function of adding preformed DHA to diets already replete in n-3 PUFA remains unclear.
- Published
- 2002
32. The Importance of Outcome Measure Research in Stargardt Disease
- Author
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Catherine A Cukras and Brett G. Jeffrey
- Subjects
Adult ,Male ,Gerontology ,genetic structures ,Fundus Oculi ,Visual Acuity ,Retinal Pigment Epithelium ,Article ,Macular Degeneration ,03 medical and health sciences ,0302 clinical medicine ,Stargardt's disease ,Outcome Assessment, Health Care ,medicine ,Humans ,Stargardt Disease ,Macula Lutea ,Prospective Studies ,Fluorescein Angiography ,Original Investigation ,business.industry ,030503 health policy & services ,Outcome measures ,medicine.disease ,eye diseases ,Stargardt disease ,Ophthalmology ,Disease Progression ,030221 ophthalmology & optometry ,Visual Field Tests ,Female ,sense organs ,Atrophy ,Visual Fields ,0305 other medical science ,business ,Tomography, Optical Coherence ,Follow-Up Studies - Abstract
New outcome measures for treatment trials for Stargardt disease type 1 (STGD1) and other macular diseases are needed. Microperimetry allows mapping of light sensitivity of the macula and provides topographic information on visual function beyond visual acuity.To measure and analyze retinal light sensitivity of the macula in STGD1 using fundus-controlled perimetry (microperimetry).This was a multicenter prospective cohort study. A total of 199 patients and 326 eyes with molecularly confirmed (ABCA4) STGD1 underwent testing with the Nidek MP-1 microperimeter as part of the multicenter, prospective Natural History of the Progression of Atrophy Secondary to Stargardt Disease (ProgStar) study. Sensitivity of 68 retinal loci was tested, and the mean sensitivity (MS) was determined; each point was categorized as "normal," "relative," or "deep" scotoma.Mean sensitivity and the number of points with normal sensitivity, relative, or deep scotomas.Mean (SD) patient age was 34.2 (14.7) years, mean (SD) best-corrected visual acuity of all eyes was 47.8 (16.9) Early Treatment Diabetic Retinopathy Study letter score (approximately 20/100 Snellen equivalent), and mean MS of all eyes of all 68 points was 11.0 (5.0) dB. The median number of normal points per eye was 49 (mean [SD], 41.3 [20.8]; range, 0-68); abnormal sensitivity and deep scotomas were more prevalent in the central macula. Mean sensitivity was lower in the fovea (mean [SD], 2.7 [4.4] dB) than in the inner (mean [SD], 6.8 [5.8] dB) and outer ring (mean [SD], 12.7 [5.3] dB). Overall MS per eye was 0.086 dB lower per year of additional age (95% CI, -0.13 to -0.041; P .001) and 0.21 dB lower per additional year of duration of STGD1 (95% CI, -0.28 to -0.14; P .001). Longer duration of STGD1 was associated with worse MS (β = -0.18; P .001), with a lower number of normal test points (β = -0.71; P .001), and with a higher number of deep scotoma points (β = -0.70; P .001). We found 11 eyes with low MS (6 dB) but very good best-corrected visual acuity of at least 72 Early Treatment Diabetic Retinopathy Study letter score (20/40 Snellen equivalent).We provide an extensive analysis of macular sensitivity parameters in STGD1 and demonstrate their association with demographic characteristics and vision. These data suggest microperimetry testing provides a more comprehensive assessment of retinal function and will be an important outcome measure in future clinical trials.
- Published
- 2017
33. Erratum to: ISCEV Standard for clinical electro-oculography (2017 update)
- Author
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Laura J. Frishman, Anthony G. Robson, Paul A Constable, Michael Bach, and Brett G. Jeffrey
- Subjects
05 social sciences ,Correction ,Electro-oculography ,Sensory Systems ,03 medical and health sciences ,Ophthalmology ,0302 clinical medicine ,Physiology (medical) ,030221 ophthalmology & optometry ,Clinical electrophysiology ,Optometry ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Psychology - Abstract
The article “ISCEV Standard for clinical electro-oculography (2017 update)”, written by Paul A. Constable, Michael Bach, Laura J. Frishman, Brett G. Jeffrey, Anthony G. Robson and for the International Society for Clinical Electrophysiology of Vision, was originally published Online First without open access.
- Published
- 2017
34. Sorting out co-occurrence of rare monogenic retinopathies: Stargardt disease co-existing with congenital stationary night blindness
- Author
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Paul A. Sieving, Nancy Huynh, Amy Turriff, Brett G. Jeffrey, and Catherine A Cukras
- Subjects
Visual acuity ,Eye Diseases ,genetic structures ,Visual Acuity ,ABCA4 ,Neurodegenerative ,Eye ,Ophthalmology & Optometry ,Polymerase Chain Reaction ,GRM6 ,Macular Degeneration ,Night Blindness ,Receptors ,Myopia ,Stargardt Disease ,Tomography ,Genetics (clinical) ,Congenital stationary night blindness ,congenital stationary night blindness ,medicine.diagnostic_test ,biology ,Eye Diseases, Hereditary ,Genetic Diseases, X-Linked ,Middle Aged ,medicine.anatomical_structure ,Hereditary ,Receptors, Glutamate ,Genetic Diseases ,Female ,medicine.symptom ,Glutamate ,Erg ,Tomography, Optical Coherence ,medicine.medical_specialty ,Mutation, Missense ,Article ,Open Reading Frames ,Rare Diseases ,Clinical Research ,Opthalmology and Optometry ,Ophthalmology ,medicine ,Genetics ,Electroretinography ,Humans ,Genetic Testing ,Eye Disease and Disorders of Vision ,Retina ,Color Vision ,business.industry ,Fundus photography ,Neurosciences ,X-Linked ,medicine.disease ,eye diseases ,Stargardt disease ,Optical Coherence ,Pediatrics, Perinatology and Child Health ,Mutation ,biology.protein ,ATP-Binding Cassette Transporters ,sense organs ,Missense ,Visual Fields ,business ,electronegative ERG - Abstract
BackgroundInherited retinal diseases are uncommon, and the likelihood of having more than one hereditary disorder is rare. Here, we report a case of Stargardt disease and congenital stationary night blindness (CSNB) in the same patient, and the identification of two novel in-frame deletions in the GRM6 gene.Materials and methodsThe patient underwent an ophthalmic exam and visual function testing including: visual acuity, color vision, Goldmann visual field, and electroretinography (ERG). Imaging of the retina included fundus photography, spectral-domain optical coherence tomography (OCT), and fundus autofluorescence. Genomic DNA was PCR-amplified for analysis of all coding exons and flanking splice sites of both the ABCA4 and GRM6 genes.ResultsA 46-year-old woman presented with recently reduced central vision and clinical findings of characteristic yellow flecks consistent with Stargardt disease. However, ERG testing revealed an ERG phenotype unusual for Stargardt disease but consistent with CSNB1. Genetic testing revealed two previously reported mutations in the ABCA4 gene and two novel deletions in the GRM6 gene.ConclusionsDiagnosis of concurrent Stargardt disease and CSNB was made on the ophthalmic history, clinical examination, ERG, and genetic testing. This case highlights that clinical tests need to be taken in context, and that co-existing retinal dystrophies and degenerations should be considered when clinical impressions and objective data do not correlate.
- Published
- 2014
35. The role of docosahexaenoic acid in retinal function
- Author
-
Drake C. Mitchell, Harrison S. Weisinger, Brett G. Jeffrey, and Martha Neuringer
- Subjects
Primates ,Rhodopsin ,medicine.medical_specialty ,Docosahexaenoic Acids ,genetic structures ,Clinical chemistry ,Biology ,Biochemistry ,Retina ,chemistry.chemical_compound ,Internal medicine ,Electroretinography ,medicine ,Animals ,Humans ,Neurochemistry ,medicine.diagnostic_test ,Organic Chemistry ,Retinal ,Cell Biology ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Docosahexaenoic acid ,Dietary Supplements ,Fatty Acids, Unsaturated ,lipids (amino acids, peptides, and proteins) ,sense organs ,Erg ,Lipidology - Abstract
An important role for docosahexaenoic acid (DHA) within the retina is suggested by its high levels and active conservation in this tissue. Animals raised on n-3-deficient diets have large reductions in retinal DHA levels that are associated with altered retinal function as assessed by the electroretinogram (ERG). Despite two decades of research in this field, little is known about the mechanisms underlying altered retinal function in n-3-deficient animals. The focus of this review is on recent research that has sought to elucidate the role of DHA in retinal function, particularly within the rod photoreceptor outer segments where DHA is found at its highest concentration. An overview is also given of human infant studies that have examined whether a neonatal dietary supply of DHA is required for the normal development of retinal function.
- Published
- 2001
36. Early binocular visual experience may improve binocular sensory outcomes in children after surgery for congenital unilateral cataract
- Author
-
Brett G. Jeffrey, Eileen E. Birch, David R. Stager, and David R. Weakley
- Subjects
medicine.medical_specialty ,Visual acuity ,genetic structures ,Contact Lenses ,medicine.medical_treatment ,Visual Acuity ,Sensory system ,Cataract Extraction ,Cataract ,Ophthalmology ,Occlusion ,Humans ,Medicine ,Prospective Studies ,Visual experience ,Strabismus ,Depth Perception ,Vision, Binocular ,business.industry ,Infant ,eye diseases ,Surgery ,Stereoscopic acuity ,Eyeglasses ,Child, Preschool ,Anesthesia ,Pediatrics, Perinatology and Child Health ,Epikeratophakia ,Congenital Unilateral Cataract ,Sensory Deprivation ,medicine.symptom ,business ,Follow-Up Studies - Abstract
Purpose: To compare the effect of intensive and reduced occlusion therapy regimens on binocular sensory outcomes, visual acuity, and the prevalence of strabismus in children after surgery for congenital unilateral cataract. Methods: Two nonrandomized groups of patients were studied prospectively: (1) an intensive occlusion group (n = 29) patched 80% of waking hours were followed for a median 6.9 years and (2) a reduced occlusion group (n = 8) patched 25% to 50% of waking hours were followed for a median 4.3 years. Six subjects in the intensive group and 4 in the reduced occlusion group had secondary intraocular lenses. Two subjects in the intensive group had epikeratophakia surgery. Binocular sensory function was assessed with random dot and contour stereoacuity tests and the Worth 4-dot test. The prevalence and age at onset of strabismus were determined from the patients' charts. Results: A higher proportion of subjects in the reduced occlusion group (50%) had stereoacuity or fusion compared with the intensive occlusion group (14%), a borderline significant difference ( P = .08). No significant difference ( P = .55) was found in median visual acuity between the intensive (20/50) and the reduced occlusion (20/55) groups. The 90% prevalence of strabismus in the intensive occlusion group was slightly higher than the 63% prevalence in the reduced occlusion group, although this difference was not significant ( P = .18). Conclusions: These results suggest that a reduced occlusion protocol may be associated with better binocular sensory outcomes and a reduced prevalence of strabismus without compromising good visual acuity in children treated for congenital unilateral cataract. (J AAPOS 2001;5:209-16)
- Published
- 2001
37. A randomized trial of different ratios of linoleic to α-linolenic acid in the diet of term infants: effects on visual function and growth
- Author
-
Robert A. Gibson, Maria Makrides, Eric L Lien, Mark A. Neumann, and Brett G. Jeffrey
- Subjects
Male ,medicine.medical_specialty ,Linolenic acid ,Linoleic acid ,Visual Acuity ,Medicine (miscellaneous) ,Growth ,Breast milk ,chemistry.chemical_compound ,Double-Blind Method ,Internal medicine ,Fatty Acids, Omega-3 ,medicine ,Humans ,Phospholipids ,Nutrition and Dietetics ,Milk, Human ,alpha-Linolenic acid ,business.industry ,Smoking ,Infant, Newborn ,alpha-Linolenic Acid ,Dietary Fats ,Surgery ,Endocrinology ,Infant formula ,chemistry ,Docosahexaenoic acid ,Linear Models ,Evoked Potentials, Visual ,Female ,Infant Food ,medicine.symptom ,business ,Breast feeding ,Weight gain - Abstract
Background There are nutritional recommendations that the ratio of linoleic to alpha-linolenic acid (LA:ALA) in formula for term infants be between 5:1 and 15:1. These recommendations were made in the absence of data on functional or clinical outcomes. Objective We compared the fatty acid status, visual evoked potential (VEP) acuity, and growth of term infants fed formula containing an LA:ALA of 10:1 or 5:1 with those of a breast-fed reference cohort. Design Formula-fed infants were allocated randomly in a double-blind fashion to receive formula with an LA:ALA of either 10:1 (16.9:1.7; n = 36) or 5:1 (16.3:3.3; n = 37) from near birth to 34 wk of age. Increased ALA was attained by replacing soy oil with low-erucic acid cannola oil. A parallel group of breast-fed infants was also recruited. Infant growth and fatty acid status were assessed at 6, 16, and 34 wk of age. VEP acuity was assessed at 16 and 34 wk. Results Infants fed the 5:1 formula had greater docosahexaenoic acid (DHA) concentrations in plasma and erythrocyte phospholipids than did infants fed the 10:1 formula, but DHA concentrations of infants fed the 5:1 formula remained less than those in breast-fed infants. The VEP acuity of all formula-fed and breast-fed infants was not significantly different at 16 and 34 wk of age. At birth, infants fed the 5:1 formula were heavier, were longer, and had a greater head circumference than infants assigned to the 10:1 formula group; this differential was maintained throughout the trial. The rate of gain in weight, length, and head circumference was not significantly different between the 2 formula-fed groups, although breast-fed infants had lower weight and length gains than did formula-fed infants between 16 and 34 wk of age. Conclusion Lowering the LA:ALA in formula from 10:1 to 5:1 by using low-erucic acid canola oil resulted in a modest increase in plasma DHA but had no effect on VEP acuity or growth rate.
- Published
- 2000
38. Serum TRPM1 autoantibodies from melanoma associated retinopathy patients enter retinal on-bipolar cells and attenuate the electroretinogram in mice
- Author
-
Brett G. Jeffrey, Wei Hong Xiong, Robert M. Duvoisin, Grazyna Adamus, Catherine W. Morgans, and Celia Gellman
- Subjects
Pathology ,Cytoplasm ,Anatomy and Physiology ,genetic structures ,Mouse ,Visual System ,Sensory Physiology ,lcsh:Medicine ,Immunoglobulin G ,Epitope ,Ion Channels ,chemistry.chemical_compound ,Epitopes ,Mice ,0302 clinical medicine ,lcsh:Science ,Skin Tumors ,0303 health sciences ,Multidisciplinary ,medicine.diagnostic_test ,Malignant Melanoma ,Animal Models ,Sensory Systems ,3. Good health ,Electrophysiology ,Protein Transport ,medicine.anatomical_structure ,Oncology ,Medicine ,Retinal Disorders ,Erg ,Research Article ,medicine.medical_specialty ,Retinal Bipolar Cells ,Cell Survival ,TRPM Cation Channels ,Biology ,Signaling Pathways ,Neurological System ,03 medical and health sciences ,Model Organisms ,medicine ,Electroretinography ,Animals ,Humans ,TRPM1 ,030304 developmental biology ,Autoantibodies ,Retina ,Paraneoplastic Syndromes, Ocular ,lcsh:R ,Autoantibody ,Cancers and Neoplasms ,Retinal ,eye diseases ,Protein Structure, Tertiary ,Mice, Inbred C57BL ,Ophthalmology ,chemistry ,Cellular Neuroscience ,Synapses ,030221 ophthalmology & optometry ,biology.protein ,lcsh:Q ,sense organs ,Molecular Neuroscience ,Neuroscience - Abstract
Melanoma-associated retinopathy (MAR) is a paraneoplastic syndrome associated with cutaneous malignant melanoma and the presence of autoantibodies that label neurons in the inner retina. The visual symptoms and electroretinogram (ERG) phenotype characteristic of MAR resemble the congenital visual disease caused by mutations in TRPM1, a cation channel expressed by both melanocytes and retinal bipolar cells. Four serum samples from MAR patients were identified as TRPM1 immunoreactive by 1. Labeling of ON-bipolar cells in TRPM1+/+ but not TRPM1−/− mouse retina, 2. Labeling of TRPM1-transfected CHO cells; and 3. Attenuation of the ERG b-wave following intravitreal injection of TRPM1-positive MAR IgG into wild-type mouse eyes, and the appearance of the IgG in the retinal bipolar cells at the conclusion of the experiment. Furthermore, the epitope targeted by the MAR autoantibodies was localized within the amino-terminal cytoplasmic domain of TRPM1. Incubation of live retinal neurons with TRPM1-positive MAR serum resulted in the selective accumulation of IgG in ON-bipolar cells from TRPM1+/+ mice, but not TRPM1−/− mice, suggesting that the visual deficits in MAR are caused by the uptake of TRPM1 autoantibodies into ON-bipolar cells, where they bind to an intracellular epitope of the channel and reduce the ON-bipolar cell response to light.
- Published
- 2013
39. An electrophysiological study on children and young adults with Alport's syndrome
- Author
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Mark Jacobs, Anthony Kriss, G. Sa, David Taylor, T. M. Barratt, and Brett G. Jeffrey
- Subjects
Adult ,Male ,medicine.medical_specialty ,Pathology ,Adolescent ,Light ,genetic structures ,Nephritis, Hereditary ,Fundus (eye) ,Eye ,Cellular and Molecular Neuroscience ,Ophthalmology ,Electroretinography ,medicine ,Humans ,Young adult ,Alport syndrome ,Child ,skin and connective tissue diseases ,medicine.diagnostic_test ,business.industry ,Glomerulonephritis ,medicine.disease ,eye diseases ,Sensory Systems ,Electrophysiology ,Transplantation ,Anterior lenticonus ,Electrooculography ,Child, Preschool ,Evoked Potentials, Visual ,Female ,Sensorineural hearing loss ,sense organs ,business ,Research Article - Abstract
Alport's syndrome is characterised by progressive haematuric nephritis and high tone sensorineural hearing loss. Ocular signs are variable, the most consistent findings being anterior lenticonus and retinal flecks in the macula and mid peripheral areas. Previous electrophysiological studies on patients with Alport's syndrome have mostly been on adult patients undergoing haemodialysis, or after renal transplantation. A group of young patients with Alport's syndrome were studied to assess if early electrophysiological changes were detectable. A total of 20 patients (15 males and five females) between the ages of 3.5 and 22 years (mean 12.7 (years) were examined and compared with control subjects. Visual evoked potentials and electroretinograms were obtained following flash and pattern reversal stimulation. Electro-oculograms were also recorded. No significant electrophysiological changes were found in any of the 20 patients, including four who had visible fundus changes.
- Published
- 1994
40. Anatomical, Physiological, and Behavioral Analysis of Rodent Vision
- Author
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Robert M. Duvoisin, Trevor J. McGill, Tammie L. Haley, Brett G. Jeffrey, and Catherine W. Morgans
- Subjects
Retina ,genetic structures ,Optokinetic reflex ,Water maze ,Stimulus (physiology) ,eye diseases ,Behavioral analysis ,medicine.anatomical_structure ,Behavioral response ,Neurotransmitter receptor ,medicine ,Reflex ,Psychology ,Neuroscience - Abstract
This chapter provides protocols for the study of rodent vision. An advantage of the visual system is that the physiological and behavioral response to the natural stimulus, light, can be measured. Moreover, the anatomy and circuitry of the system have been the subject of much research. Here, we describe our protocols for the analysis of the distribution of neurotransmitter receptors and signaling molecules in the retina by immunohistochemistry. We also explain in detail how we record the electroretinogram from mice, and we review two behavioral tests of rodent vision. One, the virtual optomotor test, makes use of the optokinetic nystagmus reflex, and thus is simple to perform and does not require training. The other, the visual water maze, is more demanding but provides a true quantitative readout of vision performance.
- Published
- 2010
41. R9AP stabilizes RGS11-G beta5 and accelerates the early light response of ON-bipolar cells
- Author
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Theresa Puthussery, Brett G. Jeffrey, Robert M. Duvoisin, Catherine W. Morgans, Neal S. Burke, Theodore G. Wensel, and R. Lane Brown
- Subjects
Retinal Bipolar Cells ,Light ,Physiology ,Cell ,Outer plexiform layer ,Biology ,Transfection ,Retina ,Article ,chemistry.chemical_compound ,Mice ,Microscopy, Electron, Transmission ,medicine ,Electroretinography ,Reaction Time ,Animals ,Humans ,Evoked Potentials ,Cell Line, Transformed ,Mice, Knockout ,medicine.diagnostic_test ,GTP-Binding Protein beta Subunits ,Wild type ,Membrane Proteins ,Retinal ,Dendrites ,Sensory Systems ,Cell biology ,Mice, Inbred C57BL ,medicine.anatomical_structure ,chemistry ,Gene Expression Regulation ,Synapses ,Transducin ,sense organs ,Neuroscience - Abstract
The rate-limiting step in the recovery of the photoreceptor light response is the hydrolysis of GTP by transducin, a reaction that is accelerated by the RGS9–Gβ5 complex, and its membrane anchor, R9AP. Similar complexes, including RGS7, RGS11, and Gβ5, are found in retinal ON-bipolar cell dendrites. Here, we present evidence that R9AP is also expressed in the dendritic tips of ON-bipolar cells. Immunofluorescent staining for R9AP revealed a punctate pattern of labeling in the outer plexiform layer, where it colocalized with mGluR6. In photoreceptors, R9AP is required for proteolytic stability of the entire regulator of G protein signaling complex, and we found that genetic deletion of R9AP also results in a marked reduction in the levels of RGS11 and Gβ5 in the bipolar cell dendrites; the level of RGS7 was unaffected, suggesting the presence of another interaction partner to stabilize RGS7. To determine the effect of R9AP deletion on the response kinetics of ON-bipolar cells, we compared the electroretinogram (ERG) between wild-type and R9AP-deficient mice. The ERG b-wave, reflecting ON-bipolar cell activity, was delayed and larger in the R9AP-deficient mice. Our data indicate that R9AP is required for stable expression of RGS11–Gβ5 in ON-bipolar cell dendrites. Furthermore, they suggest that the RGS11–Gβ5–R9AP complex accelerates the initial ON-bipolar cell response to light.
- Published
- 2010
42. Ophthalmologic Assessment of Young Patients with Alport Syndrome
- Author
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Anthony Kriss, Brett G. Jeffrey, Mark Jacobs, David Taylor, Gabriella Sa, and T. Martin Barratt
- Subjects
Adult ,Male ,medicine.medical_specialty ,Pathology ,Adolescent ,Eye Diseases ,genetic structures ,Fundus Oculi ,Hearing Loss, Sensorineural ,Eye disease ,Nephritis, Hereditary ,Cataract ,Retinal Diseases ,Electroretinography ,medicine ,Humans ,Alport syndrome ,Family history ,Child ,medicine.diagnostic_test ,business.industry ,Incidence ,medicine.disease ,Dermatology ,eye diseases ,Anterior lenticonus ,Electrooculography ,Ophthalmology ,Lens Diseases ,Child, Preschool ,Evoked Potentials, Visual ,Female ,sense organs ,Renal biopsy ,business ,Nephritis ,Retinopathy - Abstract
Background: Alport syndrome is an X-linked disease affecting basement membrane collagen. It is characterized by nephritis associated with high-tone sensorineural hearing impairment and ophthalmic signs. Although ocular changes have been described in adults, few data exist regarding the incidence of abnormal ocular features in adolescence and childhood. Methods: Fifteen male and five female patients with Alport syndrome underwent ophthalmologic, audiologic, and nephrologic assessments. All patients studied had hematuria and a positive family history of Alport syndrome. Thirteen patients had a renal biopsy that showed characteristic electron microscopic changes of the disease. Eleven patients had high-tone sensorineural impairment. Electrophysiologic investigations performed included electroretinography, visual-evoked potentials, and electro-oculography. Results: Two patients had early signs of anterior lenticonus, three had flecks in the retina, and two patients also had posterior subcapsular cataracts. None of the patients had significant electrophysiologic abnormalities. Conclusion: These findings indicate that ocular changes are uncommon and subtle in young patients with Alport syndrome, and suggest that the signs increase in frequency and severity with age.
- Published
- 1992
43. Neonatal cataract: Aetiology, pathogenesis and management
- Author
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Isabelle Russell-Eggitt, Anthony Kriss, David Taylor, Mark Goss-Sampson, Brett G. Jeffrey, and I C Lloyd
- Subjects
medicine.medical_specialty ,Pediatrics ,genetic structures ,business.industry ,Eye disease ,Infant, Newborn ,Cataract Extraction ,medicine.disease ,Infant newborn ,Cataract ,eye diseases ,Cataract extraction ,Pathogenesis ,Ophthalmology ,Recien nacido ,Epidemiology ,medicine ,Etiology ,Humans ,Female ,In patient ,sense organs ,business - Abstract
We review the epidemiology, aetiology, pathogenetic mechanisms and clinical management of neonatal cataract. Visual development and the effects of visual deprivation in the infant with congenital cataract are discussed and related to the timing of surgery. Surgical techniques and the important operative and post-operative complications are discussed. We review post-operative management and compare the different techniques available for aphakic correction, and describe the VEP changes found in patients with monocular cataract.
- Published
- 1992
44. RGS7 and -11 complexes accelerate the ON-bipolar cell light response
- Author
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Brett G. Jeffrey, J. Zhang, Robert M. Duvoisin, Neal S. Burke, Catherine W. Morgans, Tammie L. Haley, and R. Lane Brown
- Subjects
Retinal Bipolar Cells ,Patch-Clamp Techniques ,GTPase-activating protein ,Genotype ,Light ,G protein ,Blotting, Western ,Biology ,Receptors, Metabotropic Glutamate ,Mice ,Heterotrimeric G protein ,RGS9 ,Electroretinography ,Animals ,RGS2 ,G alpha subunit ,Mice, Knockout ,Microscopy, Confocal ,Hydrolysis ,Articles ,RGS17 ,Immunohistochemistry ,Cell biology ,Electrophysiology ,Mice, Inbred C57BL ,Biochemistry ,sense organs ,Guanosine Triphosphate ,RGS Proteins ,Photic Stimulation ,Signal Transduction - Abstract
The visual ON pathway, which responds to increases in light intensity, originates at the first retinal synapse between rod and cone photoreceptors and ON-bipolar cells (ON-BPCs). Light stimulation causes photoreceptors to hyperpolarize, thereby reducing the rate of glutamate release into the synaptic cleft. ON-BPCs depolarize in response to the light-induced decrease in synaptic glutamate. This unusual sign-inverting synaptic response is mediated by a metabotropic glutamate receptor, mGluR6,1 which is negatively coupled to the activation of a TRPM1-containing cation channel via the G protein Go.2–4 Deactivation of mGluR6 leads to depolarization within 100 ms,5 allowing this signaling cascade to maintain a high degree of temporal resolution. The kinetics of most heterotrimeric G protein-based signaling cascades are limited by the rate of GTP hydrolysis by the G protein α subunit. Generally, the response time is shortened by the GTPase accelerating activity provided by regulators of G protein signaling (RGS) proteins.6 Based on time constraints, RGS activity would seem to be required for the ON-BPC light response, since the intrinsic rate of GTP hydrolysis by Gαo is slow, requiring tens of seconds.7,8 The situation is similar for phototransduction in the photoreceptor outer segments. In this case, GTP hydrolysis by transducin is accelerated by interaction with RGS9–1, a member of the R7 subfamily of RGS proteins, in conjunction with its obligate binding partner Gβ5. The RGS9–1/Gβ5 complex is tethered to the disc membrane by association with a third protein, R9AP.9 Rods from transgenic mice lacking RGS9–1,10 Gβ5,11 or R9AP12 show normal activation of the photoresponse, but a profoundly slowed time course of deactivation. RGS9 is one member of a large family of more than 30 RGS proteins.13 The defining structural element of an RGS protein is the RGS domain, a conserved ∼120 amino acid sequence, through which it interacts with Gα subunits to stimulate GTP hydrolysis.14 RGS proteins in the R7 subfamily, which includes RGS6, -7, -9, and -11,15 are characterized by a G protein γ subunit-like (GGL) domain, which facilitates interaction with a unique G protein beta subunit, Gβ5. The R7 RGS proteins also contain a disheveled/EGL-10/pleckstrin homology (DEP) domain through which they can bind to G protein-coupled receptors,16 as well as the membrane-anchoring proteins, R7BP and R9AP.9,17–20 We and others have previously identified two RGS proteins of the R7 subfamily, RGS7 and -11, that co-localize with mGluR6 in the tips of ON-BPC dendrites,21–24 where they are poised to play a role in the mGluR6-based signaling pathway. In this study, we investigated the role of RGS7 and -11 complexes in the mGluR6 signal transduction pathway in mouse ON-BPCs. We compared ON-BPC responses between wild-type (WT) mice and genetically modified mice lacking RGS11 (RGS11−/−), or with a deletion mutation in RGS7 (RGS7Δ/Δ), or both. The targeted mutation in RGS7 is a deletion of exon 11, which encodes 33 amino acids spanning an interdomain region of unknown function and the first 9 amino acids of the GGL domain.25 The functionality of this deletion mutant remains to be determined. We report that the absence of RGS11 results in a delayed onset of ON-BPC light responses and increased photopic amplitudes compared with WT mice. The RGS7 deletion alone has no measurable effect on the ON-BPC responses, but it enhances the effect of the lack of RGS11 in RGS7Δ/Δ/RGS11−/− double-mutant mice.
- Published
- 2009
45. Age-related decline in rod phototransduction sensitivity in rhesus monkeys fed an n-3 fatty acid-deficient diet
- Author
-
Brett G. Jeffrey and Martha Neuringer
- Subjects
medicine.medical_specialty ,Aging ,genetic structures ,Docosahexaenoic Acids ,Biology ,Retinal Cone Photoreceptor Cells ,Article ,chemistry.chemical_compound ,Retinal Rod Photoreceptor Cells ,Internal medicine ,Fatty Acids, Omega-3 ,medicine ,Electroretinography ,Animals ,Safflower Oil ,Vision, Ocular ,chemistry.chemical_classification ,medicine.diagnostic_test ,Fatty acid ,Retinal ,Macaca mulatta ,Soybean Oil ,Endocrinology ,chemistry ,Biochemistry ,Docosahexaenoic acid ,sense organs ,Erg ,Photic Stimulation ,Visual phototransduction - Abstract
PURPOSE Docosahexaenoic acid (DHA), an n-3 fatty acid, is the major polyunsaturate in rod outer segments. The effect of long-term n-3 fatty acid deficiency on rod and cone phototransduction was investigated in the rhesus monkey. METHODS From birth to approximately = 9 years rhesus monkeys were fed an n-3-deficient diet (n = 9) known to reduce retinal DHA by 80%. Monkeys in the control group (n = 12) received either 8% alpha-linolenic acid (ALA) or 0.6% DHA, both of which support normal retinal DHA levels. None of the diets contained carotenoids. Photoactivation kinetics were assessed from the rate of increase and a P3 model fit of the ERG a-wave. Maximal cone amplitude and sensitivity were measured from the cone a-wave at 4 ms. The rod photoresponse and rod recovery were derived by using a paired flash METHOD RESULTS Rod sensitivity was reduced by 40% in the n-3-deficient monkeys at 9 but not 4.5 years. The onset of the rising phase of the photoresponse was significantly delayed (P < 0.004) at 9 years. Rod recovery was delayed by 20% in n-3-deficient monkeys at both ages, but only for bright saturating flashes. Cone phototransduction was not altered by n-3 deficiency. CONCLUSIONS Long-term dietary n-3 deficiency in the rhesus monkey was associated with two changes in retinal function. First, there was a delay in rod recovery that has remained relatively constant throughout life. Second, there was an age-dependent loss in rod phototransduction sensitivity; the lack of dietary carotenoids may have contributed to this decline.
- Published
- 2009
46. CNGB3-Achromatopsia Clinical Trial With CNTF: Diminished Rod Pathway Responses With No Evidence of Improvement in Cone Function
- Author
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Brett G. Jeffrey, Rong Wen, Weng Tao, Henry E. Wiley, Wadih M. Zein, Dario Marangoni, Ronald A. Bush, Amy Turriff, Santa J. Tumminia, Paul A. Sieving, Lisa L. Wei, Zein Wadih, M., Jeffrey Brett, G., Wiley Henry, E., Turriff Amy, E., Tumminia Santa, J., Tao, Weng, Bush Ronald, A., Marangoni, D, Wen, Rong, Wei Lisa, L., and Sieving Paul, A.
- Subjects
Male ,Time Factors ,Achromatopsia ,genetic structures ,CNGB3 ,Color Vision Defects ,Ciliary neurotrophic factor ,ECT implant ,Eye ,Ophthalmology & Optometry ,Medical and Health Sciences ,chemistry.chemical_compound ,Retinal Rod Photoreceptor Cells ,CNTF-releasing implant ,CNTF ,cone photoreceptor ,Prospective Studies ,Tomography ,human clinical trial ,Drug Implants ,medicine.diagnostic_test ,biology ,Articles ,Biological Sciences ,Middle Aged ,Sensory Systems ,Rod Photoreceptors ,Female ,achromatopsia ,Tomography, Optical Coherence ,Photopic vision ,rod photoreceptor ,Adult ,medicine.medical_specialty ,Cyclic Nucleotide-Gated Cation Channels ,Capsules ,Dark Adaptation ,Cellular and Molecular Neuroscience ,Young Adult ,Clinical Research ,Ophthalmology ,Retinitis pigmentosa ,Electroretinography ,medicine ,Humans ,Letters ,Ciliary Neurotrophic Factor ,Scotopic vision ,Eye Disease and Disorders of Vision ,business.industry ,Neurosciences ,Retinal ,medicine.disease ,Cone (formal languages) ,eye diseases ,chemistry ,Optical Coherence ,biology.protein ,sense organs ,business ,Follow-Up Studies - Abstract
Purpose Ciliary neurotrophic factor (CNTF) protects rod photoreceptors from retinal degenerative disease in multiple nonhuman models. Thus far, CNTF has failed to demonstrate rod protection in trials for human retinitis pigmentosa. Recently, CNTF was found to improve cone photoreceptor function in a canine CNGB3 achromatopsia model. This study explores whether this finding translates to humans with CNGB3 achromatopsia. Methods A five-subject, open-label Phase I/II study was initiated by implanting intraocular microcapsules releasing CNTF (nominally 20 ng/d) into one eye each of CNGB3 achromat participants. Fellow eyes served as untreated controls. Subjects were followed for 1 year. Results Pupil constriction in treated eyes gave evidence of intraocular CNTF release. Additionally, scotopic ERG responses were reduced, and dark-adapted psychophysical absolute thresholds were increased, attributable to diminished rod or rod pathway activity. Optical coherence tomography revealed that the cone-rich fovea underwent structural changes as the foveal hyporeflective zone (HRZ) became diminished in CNTF-treated eyes. No objectively measurable enhancement of cone function was found by assessments of visual acuity, mesopic increment sensitivity threshold, or the photopic ERG. Careful measurements of color hue discrimination showed no change. Nonetheless, subjects reported beneficial changes of visual function in the treated eyes, including reduced light sensitivity and aversion to bright light, which may trace to decreased effective ambient light from the pupillary constriction; further they noted slowed adaptation to darkness, consistent with CNTF action on rod photoreceptors. Conclusions Ciliary neurotrophic factor did not measurably enhance cone function, which reveals a species difference between human and canine CNGB3 cones in response to CNTF. (ClinicalTrials.gov number, NCT01648452.).
- Published
- 2014
47. Measurement of stereoacuity outcomes at ages 1 to 24 months: Randot Stereocards
- Author
-
Eileen E. Birch, Sherry L. Fawcett, Anna R. O'Connor, Brett G. Jeffrey, and Sarah E. Morale
- Subjects
Pediatrics ,medicine.medical_specialty ,Depth Perception ,Vision, Binocular ,business.industry ,Concordance ,Vision Tests ,Infant ,Reproducibility of Results ,Test (assessment) ,Clinical trial ,Stereoscopic acuity ,Cohort Studies ,Perceptual Disorders ,Ophthalmology ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Cohort ,medicine ,Normative ,Humans ,business ,Child ,Binocular vision ,Cohort study - Abstract
Purpose: The aim of the present study was to develop a simple, quick, and portable random dot stereoacuity test for measurement of binocular sensory outcomes during the first 24 months of life. Methods: Vertical bar random dot vectographs were adapted for presentation in a "Teller Acuity Card" format, called the "Randot® Stereocards." A forced-choice preferential looking protocol was used. Study participants included 386 healthy, term infants and children (normative cohort; age range: 1 month to 8 years) and 280 patients with common pediatric ophthalmic disorders (patient cohort; age range: 5 months to 9 years). Results: Overall, the success rate for test completion in the normative cohort was 91.3%. By 4 months of age, normal infants' mean stereoacuity was about 600″ and, by 6 months, 200″. Mean stereoacuity further improved to about 100″ by 12 months and 70″ by 18 months. Normative results were similar to published data obtained with laboratory-based stereoacuity tests. Randot® Stereocard data from normal children aged 2 to 6 years were similar to published normative data for the Preschool Randot® Stereoacuity Test. In the patient cohort, concordance between the Randot® Stereocards and the Preschool Randot® Test was 87%; concordance between the Randot® Stereocards and the Randot® Test was 84%. Conclusion: The Randot® Stereocards provide a simple, reliable, and valid method of obtaining a quantitative assessment of binocular vision in children up to 24 months of age for use in clinical trials and in clinical management.
- Published
- 2005
48. Visual acuity and retinal function in infant monkeys fed long-chain PUFA
- Author
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Drake C. Mitchell, Robert A. Gibson, Brett G. Jeffrey, A. Lee Chedester, Norman Salem, and Joseph R. Hibbeln
- Subjects
Male ,medicine.medical_specialty ,Visual acuity ,genetic structures ,Clinical chemistry ,Visual Acuity ,Biology ,Biochemistry ,Retinal Cone Photoreceptor Cells ,Retina ,chemistry.chemical_compound ,Dietary Fats, Unsaturated ,Retinal Rod Photoreceptor Cells ,Internal medicine ,medicine ,Electroretinography ,Animals ,Arachidonic Acid ,medicine.diagnostic_test ,Organic Chemistry ,Retinal ,Cell Biology ,Anatomy ,Endocrinology ,medicine.anatomical_structure ,chemistry ,Animals, Newborn ,Fatty Acids, Unsaturated ,Female ,medicine.symptom ,Erg ,Visual phototransduction - Abstract
Previous randomized clinical trials suggest that supplementation of the human infant diet with up to 0.35% DHA may benefit visual development. The aim of the current study was to assess the impact of including arachidonic acid (AA) and a higher level of DHA in the postnatal monkey diet on visual development. Infant rhesus monkeys were fed either a control diet (2.0% alpha-linolenic acid as the sole n-3 FA) or a supplemented diet (1.0% DHA and 1.0% AA) from birth. Visual evoked potential acuity was measured at 3 mon of age. Rod and cone function were assessed in terms of parameters describing phototransduction. Electroretinogram (ERG) amplitudes and implicit times were recorded over a wide intensity range (-2.2 to 4.0 log scot td-sec) and assessed in terms of intensity response functions. Plasma DHA and AA were significantly increased (P < 0.001) in the diet-supplemented monkeys compared with the control monkeys. There was an approximately equal effect of diet for the rod phototransduction parameters, sensitivity, and capacitance but in the opposite directions. Diet-supplemented monkeys had significantly shorter b-wave implicit times at low retinal illuminances (
- Published
- 2002
49. Preschool Worth 4-Shape test: testability, reliability, and validity
- Author
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Solange Rios Salomão, Brett G. Jeffrey, Eileen E. Birch, Adriana Berezovsky, Sherry L. Fawcett, David R. Stager, Sarah E. Morale, and M.Cecilia Lapa
- Subjects
medicine.medical_specialty ,Depth Perception ,Vision, Binocular ,business.industry ,Concordance ,Vision Tests ,Vision Disorders ,Visual Acuity ,Reproducibility of Results ,Gold standard (test) ,Audiology ,Sensitivity and Specificity ,Test (assessment) ,Stereoscopic acuity ,Ophthalmology ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Medicine ,Humans ,business ,Child ,Social psychology ,Reliability (statistics) ,Testability - Abstract
The Worth 4-Dot is used to assess binocular fusion, but it is difficult to use with young children. We modified the Worth 4-Dot by replacing the circles with shapes while maintaining the same color configuration. The purpose of this study was to determine the testability, reliability, and validity of the Worth 4-Shape test.Subjects aged 2 to 8 years and 4 patients aged over 8 years with best-corrected visual acuity of 20/40 or greater (n = 131 patients, n = 123 normals) attempted test and retest at 35 cm and 3m using the Worth 4-Shape and Worth 4-Dot. To provide a gold standard, medical history, bifoveal fixation, and stereoacuity were reviewed.Testability of the Worth 4-Shape was significantly higher than the Worth 4-Dot both in children aged less than 4 years (95.9% vs 79.5% at 35 cm, P.001; 79.5% vs 55.1% at 3 m, P.001) and older than 4 years (98.5% vs 88.6% at 35 cm, P.001; 90.9% vs 82.4% at 3m, P =.04). Test-retest analysis found comparable concordance for the Worth 4-Shape and Worth 4-Dot tests (P.3). The sensitivity and specificity of the Worth 4-Shape (92%, 97%) and Worth 4-Dot (90%, 94%) were comparable. Between-test analysis found 96% agreement between both tests at 35 cm and 97% agreement at 3m.The success rate for the Worth 4-Shape is higher than the Worth 4-Dot, especially in children aged less than 4 years, and has equivalent accuracy. The Worth 4-Shape test-retest reliability is high supporting its validity for use with young children.
- Published
- 2002
50. n-3 fatty acid deficiency alters recovery of the rod photoresponse in rhesus monkeys
- Author
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Brett G, Jeffrey, Drake C, Mitchell, Robert A, Gibson, and Martha, Neuringer
- Subjects
Dietary Fats, Unsaturated ,Docosahexaenoic Acids ,Retinal Rod Photoreceptor Cells ,Electroretinography ,Animals ,alpha-Linolenic Acid ,Macaca mulatta ,Vision, Ocular - Abstract
Docosahexaenoic acid (DHA) is the major polyunsaturated fatty acid within rod outer segments. Varying the dietary content of DHA or its precursor, alpha-linolenic acid (ALA), can alter retinal DHA levels. The purpose of the present study was to assess rod phototransduction and recovery in rhesus monkeys raised on diets with different DHA and ALA content.Adult rhesus monkeys had consumed from birth a diet low in ALA (0.3%) and known to induce an 80% reduction in retinal DHA. They were compared with groups receiving 8% ALA or 0.6% DHA, both of which support normal retinal DHA levels. Rod recovery was assessed with a double-flash protocol using a-wave saturating test flashes. The recovery of rod-isolated ERG a-wave amplitude was analyzed to determine Tc, the time to initiation of rod recovery, and T50, the time from initiation to 50% of full recovery. Phototransduction was assessed from the fit of a quantitative model to the leading edges of rod-isolated ERG a-waves. ERG a- and b-wave amplitudes and implicit times were also measured.Rod recovery (T50) was delayed by 30% and ERG implicit times by 5% in monkeys in the low ALA group compared with the other groups. There was no significant effect of diet on ERG amplitudes, the time to initiation of rod recovery, or the parameters describing phototransduction.The results indicate that mechanisms involved in deactivation and rod recovery are selectively altered in monkeys raised on a low-ALA diet whereas, at the flash intensities used, the mechanisms underlying phototransduction remain unaffected.
- Published
- 2002
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