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Purpose: To determine neuroretinal function with multifocal electroretinogram (mfERG) in diabetic subjects without retinopathy. Methods: Multifocal electroretinogram (mfERG) was performed in 18 eyes of 18 diabetic subjects without retinopathy and 17 eyes of 17 age and gender-matched healthy control participants. Among 18 diabetic subjects, two had type 1 and 16 had type 2 diabetes. MfERG responses were averaged by the retinal areas of six concentric rings and four quadrants, and 103 retinal locations; N1-P1 amplitude and P1-implicit time were analysed. Results: Average mfERG N1-P1 amplitude (in nv/deg) of 103 retinal locations was 56.3 ± 17.2 (mean ± SD) in type 1 diabetic subjects, 47.2 ± 9.3 in type 2 diabetic subjects and 71.5 ± 12.7 in controls. Average P1-implicit time (in ms) was 43.0 ± 1.3 in type 1 diabetic subjects, 43.9 ± 2.3 in type 2 diabetic subjects and 41.9 ± 2.1 in controls. There was significant reduction in average N1-P1 amplitude and delay in P1-implicit time in type 2 diabetic subjects in comparison to controls. mfERG amplitude did not show any significant correlation with diabetes duration and blood sugar level. However, implicit time showed a positive correlation with diabetes duration in type 2 diabetic subjects with diabetes duration ≥5 years. Conclusions: This is the first study in a Nepalese population with diabetes using multifocal electroretinography. We present novel findings that mfERG N1-P1 amplitude is markedly reduced along with delay in P1-implicit time in type 2 diabetic subjects without retinopathy. These findings indicate that there might be significant dysfunction of inner retina before the development of diabetic retinopathy in the study population, which have higher prevalence of diabetes than the global estimate and uncontrolled blood sugar level. [ABSTRACT FROM AUTHOR]

To present two pediatric cases where multifocal electroretinogram (mfERG) was able to establish an earlier diagnosis compared to full field electroretinogram (ERG) Case 1: an 11-year-old boy with reduced visual acuity, pale discs, macular pigmentation with white dots bilaterally. Case 2: a 12-year-old girl with reduced vision in her right eye, slight pallor of the right optic disc, intense pigmentation at both maculae and scattered punctate lesions throughout the peripheral fundi. Both had been investigated with electrodiagnostic tests according to the International Society of Clinical Electrophysiology for Vision protocol. Full-field ERGs for both children showed normal responses. Case 1: mfERG revealed a severe reduction in function in the inner 20°. Case 2: mfERG showed attenuated responses in each eye. Clinical examination and mfERG were consistent with Stargardt disease. mfERG is applicable to children and is a sensitive tool for early diagnosis of retinal dystrophies. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to report a patient who diagnosed with acute zonal occult outer retinopathy (AZOOR). A 31-year-old female referred with a chief complaint of headache and photopsia of her right eye for 2 years. At her detailed ophthalmologic examination, her best-corrected visual acuities were 20/20 and intraocular pressures were 16 mm-Hg bilaterally. Biomicroscobic examination showed no pathological view in anterior segment, ocular media and retina. Bilateral optical coherence tomography (OCT) showed no abnormalities. Humphrey visual field examination (full threshold 30-2) revealed periferic arcuat visual field defect at inferior temporal quadrant of the right eye. No visual field defect was seen in her left eye. ERG and multifocal ERG were abnormal. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study is to report the clinical case of a 53-year-old woman whose presenting manifestation of primary intraocular lymphoma (PIOL) was unilateral retinal degeneration. Method: A case report was created with review of clinical, imaging, electrophysiologic, and pathological investigations. Results: A 53-year-old woman with a distant history of ocular herpes simplex developed progressive central visual loss and intermittent photopsia over 4 years in her right eye. Ophthalmic examination revealed reduced visual acuity OD, central scotoma, and minimal ocular findings. Autofluorescence and infrared imaging revealed mild reflectance changes in the temporal macula, and spectral-domain optical coherence tomography identified mild disruptions of inner segment/outer segment junctions in the subfoveal region of the right eye. A mild window defect was seen on fluorescein angiography. Electrophysiology with multifocal electroretinogram (ERG) revealed evidence of unilateral macular dysfunction. Full-field ERGs revealed progressive global retinal dysfunction over 6 months, with unilateral decreases in amplitude and implicit time shifts, as seen in cases of autoimmune retinopathies. The eye eventually exhibited mild vitreous cellular infiltration on ophthalmoscopic examination, and vitrectomy diagnosed B cell non-Hodgkin's lymphoma. Further evaluation revealed no evidence of central nervous system or systemic disease, consistent with occult PIOL. Conclusions: This case illustrates an atypical presentation of PIOL characterized by unilateral retinal disease presenting with symptoms and signs of macular dysfunction. Clinical and ERG features evolved into an acute zonal occult outer retinopathy (AZOOR)-like phenotype. PIOL should be considered in atypical cases of AZOOR with vitreal reactions, and some cases of AZOOR may be related to B cell lymphocyte disorders. [ABSTRACT FROM AUTHOR]

Purpose: To study the relationship between macular function assessed by multifocal electroretinogram (mfERG) and morphological changes evaluated with optical coherence tomography (OCT) and fundus photography in patients with drusen maculopathy. Methods: Ten patients (age 71 ± 5 years) with drusen maculopathy were compared to fifteen healthy control patients (age 67 ± 7 years). One eye per patient was examined with OCT, color fundus pictures, and mfERG (103 hexagons) recorded in nine areas corresponding to the nine areas of the OCT retinal map. Drusen density for every separated area was registered. Results: All nine areas in the maculopathy group demonstrated prolonged implicit time compared to healthy controls; the mean value for the maculopathy group was 31.3 milliseconds (95% confidence intervals [CI]: 30.9-31.6) vs 27.9 milliseconds (95% CI: 27.5-28.2; P = 0.006) for the control group. The amplitude in the foveal area was lower in the maculopathy group; the mean value for the maculopathy group was 25.1 nV/deg2 (95% CI: 18.4-31.7) vs 33.9 nV/deg2 (95% CI: 27-40.9; P = 0.03) for the control group. mfERG in the maculopathy group demonstrated no differences in areas with or without drusen. There was no correlation between the retinal thickness assessed with OCT and the mfERG response. Conclusion: Eyes with drusen maculopathy demonstrated functional changes compared to healthy controls evaluated with mfERG. Drusen seems to be associated with general macular dysfunction. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate structural and functional changes in non-pathologic myopic fundus using multifocal electroretinogram (mfERG) and spectral domain-optical coherence tomography (SD-OCT). Methods: A total of 90 myopic subjects underwent mfERG and SD-OCT. The subjects were divided into four groups according to spherical equivalent refractive error: Group 1 (−0.50 to −2.75 D), Group 2 (−3.00 to −5.75 D), Group 3 (−6.00 to −9.75 D), and Group 4 (−10.0 to −15.0 D). Total retinal thickness, photoreceptor retinal thickness (PR), outer nuclear retinal thickness and mid-inner retinal thickness (MIR) were measured using SD-OCT in foveola and two perifoveal retinal regions 2.0 mm nasal and temporal from the foveola. The amplitude and implicit time of N1 and P1 mfERG responses were analyzed using six-concentric-ring grouping. Correlations between each retinal thickness, amplitude, and implicit time among the four myopic groups were analyzed. Results: PR thickness in the foveola and MIR thickness in the perifoveal retina were significantly reduced with increasing myopic refractive errors ( p = 0.001, respectively). Significant correlations appeared between N1 amplitude, P1 amplitude, P1 implicit time, and refractive errors ( p = 0.001, respectively). Significant correlations appeared between MIR thickness and N1, P1 amplitude ( p = 0.001, respectively) as well as N1, P1 implicit time ( p = 0.02 and 0.03, respectively) in the perifoveal retina corresponding to ring 4. Conclusions: The correlation between structural and functional changes in myopia should be considered when interpreting retinal structure and function using SD-OCT and mfERG, especially in high myopia. [ABSTRACT FROM AUTHOR]

Purpose In this study we examine neuroretinal function in five amblyopes, who had been shown in previous functional MRI ( fMRI) studies to have compromised function of the lateral geniculate nucleus ( LGN), to determine if the fMRI deficit in amblyopia may have its origin at the retinal level. Methods We used slow flash multifocal ERG (mf ERG) and compared averaged five ring responses of the amblyopic and fellow eyes across a 35 deg field. Central responses were also assessed over a field which was about 6.3 deg in diameter. We measured central retinal thickness using optical coherence tomography. Central fields were measured using the MP1-Microperimeter which also assesses ocular fixation during perimetry. Mf ERG data were compared with fMRI results from a previous study. Results Amblyopic eyes had reduced response density amplitudes (first major negative to first positive (N1-P1) responses) for the central and paracentral retina (up to 18 deg diameter) but not for the mid-periphery (from 18 to 35 deg). Retinal thickness was within normal limits for all eyes, and not different between amblyopic and fellow eyes. Fixation was maintained within the central 4° more than 80% of the time by four of the five participants; fixation assessed using bivariate contour ellipse areas ( BCEA) gave rankings similar to those of the MP-1 system. There was no significant relationship between BCEA and mf ERG response for either amblyopic or fellow eye. There was no significant relationship between the central mf ERG eye response difference and the selective blood oxygen level dependent ( BOLD) LGN eye response difference previously seen in these participants. Conclusions Retinal responses in amblyopes can be reduced within the central field without an obvious anatomical basis. Additionally, this retinal deficit may not be the reason why the LGN BOLD (blood oxygen level dependent) responses are reduced for amblyopic eye stimulation. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether significant correlations existed between the morphological and functional parameters of the macular region of eyes with open-angle glaucoma (OAG). Methods: Forty eyes of 40 OAG patients were studied. The morphological parameters were obtained by optical coherence tomography (OCT), and the functional parameters were acquired by automated Humphrey Field Analyzer (HFA) and multifocal electroretinograms (mfERGs). All of the tests were performed within 6 months of each other. The retinal thickness was determined by OCT in the nine Early Treatment of Diabetic Retinopathy Study (ETDRS) sectors of the macula, the fovea, and the four quadrants of the inner and an outer ring. The amplitudes of the second-order kernel responses of the mfERGs in the central 5° including the amplitude ratio of the nasal to temporal hemispheres ( N/ T amplitude ratio) were analyzed. The total mean deviation of the HFA corresponding to each OCT region was measured. The correlation between the different parameters was determined by coefficients of correlation and linear regression analyses. Results: The N/ T amplitude ratio of the second-order kernel responses of the mfERGs was significantly correlated with the retinal thickness in the inferior quadrant ( r = −0.44; P = 0.004). There was a significant correlation between the N/ T amplitude ratio and the threshold in the superior quadrant measured by the HFA Central 10-2 program ( r = −0.40; P = 0.011) and also between the N/ T amplitude ratio and the total deviation in the superior quadrant ( r = −0.40; P = 0.010). There were significant correlations between the inferior retinal thickness and the average threshold and the TD in superior ( r = 0.70, P < 0.001; r = 0.692, P < 0.001, respectively), nasal ( r = 0.53, P < 0.001; r = 0.53, P < 0.001, respectively), and temporal ( r = 0.46, P = 0.003; r = 0.44, P = 0.004, respectively) quadrants. Conclusions: Functional glaucomatous changes determined by mfERGs and perimetry are significantly correlated with the morphological changes determined by OCT. [ABSTRACT FROM AUTHOR]

A 72-year-old woman presented with unexplained, progressive, painless visual loss in the right eye during the past six months. At presentation visual acuity ( VA) was 3/60 in the right eye and 6/6 in the left eye. Anterior segment examination and intraocular pressures were normal. Dilated fundoscopy revealed significant macular oedema in the right eye and a normal fundus appearance in the left eye. Her medical history was noteworthy for breast ductal carcinoma in situ, for which she had undergone right mastectomy three years earlier. She had not received chemotherapy or radiotherapy but she had been under treatment with letrozole 2.5 mg/day over the past three years. She did not receive any other medication. Optical coherence tomography showed intraretinal fluid and a significant increase in retinal thickness in the foveal and parafoveal areas, while fluorescein angiography detected foveal hyperfluorescence and leakage of the dye in the late phase. Multifocal electroretinogram showed a decreased response in both eyes. In suspicion of letrozole-related retinopathy, the patient was advised to stop the medication. The patient agreed to receive an intravitreal injection of 0.05 ml/0.5 mg ranibizumab. One month later, VA in the right eye was 6/9 and macular oedema had apparently improved. This is the first reported case of letrozole-associated macular oedema treated with intravitreal ranibizumab. [ABSTRACT FROM AUTHOR]

Purpose To investigate the correlations of the global flash multifocal electroretinogram (MOFO mfERG) with common clinical visual assessments-Humphrey perimetry and Stratus circumpapillary retinal nerve fiber layer (RNFL) thickness measurement in type II diabetic patients. Methods Forty-two diabetic patients participated in the study: Ten were free from diabetic retinopathy (DR), while the remainder suffered from mild to moderate nonproliferative diabetic retinopathy. Fourteen age-matched controls were recruited for comparison. MOFO mfERG measurements were made under high- and low-contrast conditions. Humphrey central 30-2 perimetry and Stratus OCT circumpapillary RNFL thickness measurements were also performed. Correlations between local values of implicit time and amplitude of the mfERG components [direct component (DC) and induced component (IC)], and perimetric sensitivity and RNFL thickness were evaluated by mapping the localized responses for the three subject groups. Results MOFO mfERG was superior to perimetry and RNFL assessments in showing differences between the diabetic groups (with and without DR) and the controls. All the MOFO mfERG amplitudes (except IC amplitude at high contrast) correlated better with perimetry findings (Pearson's r ranged from 0.23 to 0.36, p < 0.01) than did the mfERG implicit time at both high and low contrasts across all subject groups. No consistent correlation was found between the mfERG and RNFL assessments for any group or contrast conditions. The responses of the local MOFO mfERG correlated with local perimetric sensitivity but not with RNFL thickness. Conclusion Early functional changes in the diabetic retina seem to occur before morphological changes in the RNFL. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the association of the luminance-modulation global flash multifocal electroretinogram (mfERG) and other clinical assessments of vision in subsets of subjects at high risk of developing glaucomatous damage. Methods: Eighteen subjects (28 eyes) with asymmetric glaucoma and ocular hypertension were measured in this longitudinal study of visual field, OCT, and multifocal electroretinogram (mfERG). Five ophthalmic examinations were scheduled, once every 12 months over a 4-year period. The mfERG was assessed using a luminance-modulated global flash stimulation paradigm. The adaptive index which we have reported previously was calculated. Results: There was a significant thinning of the peripapillary retinal nerve fiber layer over the course of the study for eyes with ocular hypertension, or for fellow eyes with asymmetric glaucoma which initially had an abnormal adaptive index; such eyes showed a thinning rate of −3.59 and −3.69 μm/year, respectively. However, no significant thinning was found for eyes which initially had a normal adaptive index. Two subjects were shown to have glaucomatous damage, confirmed by abnormal thinning of the retinal nerve fiber layer and visual field loss respectively at the last visit. However, these patients had shown an abnormal adaptive index in the mfERG measurement at the first visit. Conclusions: The adaptive index calculated from the measurement of luminance-modulated global flash mfERG is useful for predicting progression of signs related to glaucoma, especially in high-risk groups. The abnormal adaptive index reflects the change in fast-adaptive mechanisms in the retina and indicates the risk of developing glaucoma. [ABSTRACT FROM AUTHOR]

The clinical multifocal electroretinogram (mfERG) is an electrophysiological test of local retinal function. With this technique, many local ERG responses are recorded quasi-simultaneously from the cone-driven retina under light-adapted conditions. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV: ), replaces the ISCEV guidelines for the mfERG published in 2007. Standards for performance of the basic clinical mfERG test with a stimulus array of 61 or 103 hexagons, as well as for reporting the results, are specified. [ABSTRACT FROM AUTHOR]

We compared the suitability of pentobarbital sodium (PB) and propofol (PF) anesthetics for multifocal electroretinograms (mfERGs) in rhesus macaques. mfERGs were collected from 4 ocularly normal rhesus macaques. All animals were pre-anesthetized with intramuscular ketamine (10-15 mg/kg). Intravenous PB induction/maintenance levels were 15 mg/kg/2-10 mg/kg and for PF, 2-5 mg/kg/6-24 mg/kg/h. There were 3 testing sessions with PB anesthesia and 5-7 testing sessions with PF anesthesia. All PB sessions were carried out before PF. First-order (K1) and second-order (first slice) kernels (K2.1) response density amplitude (RDA), implicit time (IT), and root mean square signal-to-noise ratios (RMS SNR) of the low-frequency (LFC) and high-frequency (HFC) components were evaluated. The use of PF or PB anesthesia resulted in robust, replicable mfERGs in rhesus macaques; however, RMS SNR of K1 LFC in ring and quadrant analyses was significantly larger for PF than for PB. Additionally, K1 RDA under PF was significantly larger than under PB for N1, P1, and P2 components (ring and quadrant) and for N2 (quadrant). PF IT was significantly prolonged (<1 ms) relative to PB IT for N1, P1 (ring), and N1 (quadrant), while PB IT was significantly prolonged (0.8-4.2 ms) relative to PF IT for N2 and P2 (ring and quadrant). K1 HFC and K2.1 LFC did not differ significantly between PB and PF in the ring or quadrant analyses. The response differences found with PB and PF anesthesia likely arise from variable relative effects of the anesthetics on retinal γ-aminobutyric acid (GABA) receptors, and in part, on glycine and on glutamate receptors. Given the advantages of a stable anesthetic plane with continuous intravenous infusion and a smoother, more rapid recovery, PF is an appealing alternative for mfERG testing in rhesus macaques. [ABSTRACT FROM AUTHOR]

Aim of the Study: To establish the normative database for multifocal electroretinogram (mfERG) parameters in a normal emmetropic population. To correlate the data so obtained with the central macular thickness obtained using the optical coherence tomography (OCT) scan. Materials and Methods: mfERG data were obtained from 222 eyes of 111 emmetropic subjects. The amplitude (nv/deg2) and implicit times (ms) of the first-order kernel mfERG responses (N1, P1, and N2 waves) were obtained and grouped into five rings (Ring 1: Central 2°, Ring 2: 2-5°, Ring 3: 5-10°, Ring 4: 10-15°, Ring 5: >15°). The central macular thickness (CMT) was obtained using the macular thickness scan protocol of the OCT. Results: The mfERG data obtained were used to create a normative database. The amplitudes of the mfERG waves were maximum in the fovea and progressively decreased with increasing eccentricity (P = 0.0001). The latencies of the P1 and N2 waves were longest in the central ring and progressively shortened with eccentricity (P = 0.0001). No statistically significant correlations were observed between central ring 1 parameters and the CMT. Conclusion: This study establishes normative database for mfERG parameters in an emmetropic population. No statistically significant correlation was noted between CMT and mfERG parameters. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the value of multifocal electroretinogram (mfERG) and optical coherence tomography (OCT) in predicting post-operative visual acuity (post-VA) after removal of an idiopathic epiretinal membrane (ERM). Fifty-one eyes of 51 patients with an idiopathic macular ERM were examined by OCT and mfERG before three-port pars plana vitrectomy with removal of the ERM. The parameters of the OCT images and mfERGs, pre-operative visual acuity (pre-VA) and the duration of symptoms (DS) were compared with the post-VA. The pre-VA (r = 0.570, p < 0.001) and the duration of the symptoms (r = 0.389, p < 0.035; n = 35) were significantly correlated with the post-VA. The central retinal thickness (CRT) was significantly correlated with the pre-VA (r = 0.379, p < 0.01) and the post-VA (r = 0.318, p < 0.03). The amplitudes of macular electroretinogram (amERGs) were not significantly correlated with the pre-VA or post-VA. The CRT to amERG ratio (CRT/amERG) was correlated with the post-VA (r = 0.429, p < 0.002) but not with the pre-VA (p > 0.1). Comparative analyses among groups of cases based on CRT/amERG showed significant differences in the post-VA but not in the pre-VA and the duration of symptoms. As with the large CRT/amERG, the pre-operative morphologically thickened and electroretinographically reduced retinas have a greater likelihood of being affected by the irreversible photoreceptor damages that could have been masked or modified by other factors before the removal of the ERM. Because the CRT/amERG values are obtained objectively, they should be valuable in predicting the post-operative visual function along with the pre-VA and the duration of symptoms. [ABSTRACT FROM AUTHOR]

The aim was to evaluate the macular structure and function in children with human immunodeficiency virus (HIV) disease without cytomegalovirus retinitis or visual symptoms. Thirty-eight eyes of 19 HIV-positive children (Group A) were examined. Group B included 20 (40 eyes) age- and sex-matched control subjects. Each individual underwent a complete ophthalmic examination, optical coherence tomography (OCT) scan and multifocal electroretinogram (mfERG) recording. In all patients, visual acuity and colour vision testing were normal. The mean foveal thickness in groups A and B was 190.28 ± 26.58 (SD) µm and 169.47 ± 10.17 µm, respectively (p = 0.0002). In Group A, the mean retinal response density of the fovea (area 1) was 19.87 ± 10.16 nV/deg and the latency was 38.56 ± 1.18 ms. In the parafoveal area (area 2), the mean retinal response density was 10.82 ± 2.34 nV/deg and the mean latency was 36.52 ± 1.73 ms. In the perifoveal area (area 3), the mean retinal response density was 10.83 ± 0.90 nV/deg and the mean latency was 36.36 ± 1.90 ms. In Group B, the mean retinal response density of area 1 was 22.02 ± 0.9 nV/deg and the mean latency was 32.56 ± 1.25 ms. In area 2, the mean retinal response density was 12.23 ± 0.55 nV/deg and the mean latency was 30.84 ±1.22 ms. Finally, in the perifoveal area (area 3), the mean retinal response density was 12.74 ± 0.44 nV/deg and the mean latency was 29.7 ± 11.09 ms. The differences in amplitude and latency were statistically significant. Increased foveal thickening and significant decrease of the electrical activity of areas 1, 2 and 3 were found in HIV-positive children. These findings suggested some subclinical dysfunction of the photoreceptors and the inner retinal layers of the fovea in HIV-positive children with normal vision and without ocular disease. [ABSTRACT FROM AUTHOR]

The aim was to investigate multifocal electroretinogram (mfERG) findings in Bietti's crystalline dystrophy (BCD) using a retrospective, non-interventional, consecutive case series. Five patients, two women and three men (mean age 31.8 years), clinically diagnosed with BCD underwent full-field electroretinogram (ffERG) and mfERG using Burian Allen bipolar contact lens electrode on the VERIS Science 5.2.1X system. The ffERG and mfERG parameters of patients with Bietti's crystalline dystrophy were compared with age-matched normal subjects. The N1, P1 amplitudes and implicit times of the mfERG for the six concentric rings were analysed. The ffERG showed significant decreases in the amplitude of the scotopic and photopic responses in all patients; however, implicit times were only mildly prolonged. Rod response implicit times appeared to be more affected than the cone responses. The N1 and P1 amplitudes of mfERG showed a significant decrease in all rings in all patients. N1 implicit times were significantly delayed in rings 3, 4 and 5. The P1 implicit time was significantly delayed in all rings except 1 and 6. The mfERG in Bietti's crystalline dystrophy can provide insight into the functional retina and objectively help to quantify the extent of retinal damage. [ABSTRACT FROM AUTHOR]

The purpose of this project was to investigate the changes in macular function and macular morphology of severe non-proliferative diabetic retinopathy (NPDR), due to photocoagulation, using the multifocal electroretinogram (mfERG) and optical coherence tomography (OCT). Thirty-five volunteers were in the control group, with one eye per person examined with the mfERG. Both the mfERG and OCT were conducted on 30 patients with diabetes who had severe NPDR before, and two, seven and 14 days after, treatment with photocoagulation. Compared with the control group, the P1 and N1 response densities in the patients with NPDR appeared to decrease significantly at rings 2-3 and rings 3-4, respectively, whereas no difference was seen in the implicit times. At two days after photocoagulation, the P1 and N1 response densities decreased significantly in ring 1 and they were still lower than the pre-photocoagulation values at 14 days after photocoagulation. In addition, no change was found in the implicit times before and after photocoagulation. There was no obvious difference in the macular thickness after treatment. At two days after treatment, the P1 response density in ring 1 negatively correlated with the corresponding macular thickness. The para-macular function was significantly impaired in those patients with severe NPDR and photocoagulation reduced the central macular function. Even after 14 days, the central macular function had not returned to pre-photocoagulation levels. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate, by optical coherence tomography (OCT) and multifocal electroretinography (mfERG), the macular function of eyes with choroidal neovascularisation due to age-related macular degeneration (AMD) before and after the intravitreal use of ranibizumab. Fifteen eyes with choroidal neovascularisation due to AMD were studied with OCT and mfERG before, during and at the end of the treatment, one year after the first injection of ranibizumab. The eyes received 0.5 mg ranibizumab every month for the first three months, followed by doses every three months. Thus, during the 12-month study, a total of six ranibizumab injections were given. The level of visual acuity increased significantly with time. A linear mixed-effect analysis showed a borderline negative association between the amount of foveal thickness and time, with a decrease in the mean foveal thickness for one time increment. The retinal response density of the mfERG showed a significant increase in ring 1 and remained almost unchanged in ring 2, whereas there was a statistically insignificant increase in ring 3. Finally, the mean latency remained unchanged throughout the 12 months of treatment in all three rings. The intravitreal use of ranibizumab might result in an increase of the mfERG in the foveal area. Only a borderline inverse association was shown between the amount of foveal thickness and time. Also, the level of visual acuity statistically significantly improved over time. Randomised long-term clinical trials are needed to determine the potential clinical benefit of ranibizumab. [ABSTRACT FROM AUTHOR]

The present study investigated retinal adaptive responses in concert with the modulation of forward and backward adaptation induced by periodic global flashes using the global flash multifocal electroretinogram (mfERG). Six normal subjects were recruited for global flash mfERG measurements, which consisted of 103 scaled hexagonal elements followed by a global flash frame. In experiments I and II, with constant luminance maintained in both local and global flash frames, the number of dark frames was independently varied and these frames were either inserted prior to or following the global flash frame to investigate the forward or backward adaptive effect of the global flash on the mfERG. In experiment III, the number of dark frames was fixed but the luminance of the global flash frame was varied with constant luminance of the focal flash. This was used to demonstrate that the adaptive effect related not to time but to variation of luminance. All the central, para-central and peripheral direct component amplitudes were found to be significantly influenced by variation of the number of dark frames (p < 0.01). Reducing the forward adaptive effect of the global flash enhanced the direct component response and it became steady after five dark frames were inserted following the global flash. Reducing the backward adaptive effect of the global flash also enhanced the direct component response but it started reducing after four dark frames were inserted prior to the global flash frame. These changes were different with luminance modulation of the global flash intensity with fixed dark frames, while the direct component amplitude grew approximately linearly with decreasing mean luminance of the global flash stimulation. The retina plays a major role in visual adaptation. Both forward and backward adaptive effects of the global flash on the direct component have been illustrated in this study. The results show that the forward and backward adaptive phenomena in the global flash mfERG are different and demonstrate that backward adaptation is found at the retinal level. [ABSTRACT FROM AUTHOR]

Glaucoma is one of the most important eye diseases resulting in blindness worldwide. It affects the inner retina and is without signs and symptoms in the early stages, making early detection of glaucoma important for eye care professionals. Electroretinography (ERG) is an objective technique used to measure retinal electrical responses, which directly reflect retinal function. The multifocal electroretinogram (mfERG) is a relatively new tool in this area. Various modifications of the mfERG stimulation paradigms such as fast flicker, low contrast, slow sequence, global flash and luminance-modulation have been developed in recent years. Using these techniques and a better understanding of the mfERG characteristics has resulted in greater effectiveness of the mfERG in the diagnosis of glaucoma. It is likely that sensitive clinical mfERG measurement protocols for early detection of glaucomatous damage will be possible in the near future. [ABSTRACT FROM AUTHOR]

The effects of chloroquine intake on the retinal function in a Brazilian population of patients were assessed by multifocal electroretinography. Twenty-four randomly chosen eyes of patients treated with chloroquine for rheumatoid arthritis and systemic lupus erythematosus were examined using multifocal electroretinography (mfERG). Control measurements were acquired from 21 randomly chosen eyes of age-matched healthy subjects. None of the study participants had an inherited retinal disease or a Snellen visual acuity reduced to less than 20/40. In patients and control subjects, cumulative chloroquine dose, total daily dose, duration of treatment, retinal examination, visual field defects, visual acuity, and the mfERG were assessed. The average amplitudes and implicit times of the N1, P1, and P2 components of the mfERGs were measured in the central hexagon (R1) and in five rings (R2-R6). The values measured in patients and normal subjects were compared. The P1 amplitudes in R2 were significantly decreased in the patients. In addition, the amplitudes of N1 and N2 in R1 were significantly smaller in the patients. The implicit times of none of the components were significantly different between patients and controls. The response amplitude was not significantly correlated with cumulative dose and duration of intake. There was no correlation with retinal appearance, visual field, and visual acuity. In agreement with earlier data, the central mfERG amplitudes were decreased in chloroquine patients indicating functional alterations in the retina. These changes are also present in a Brazilian population suggesting that the effects of chloroquine are general and that genetic background and life circumstances probably have, if at all, only little effect. [ABSTRACT FROM AUTHOR]

new constituent of visual attention theory is proposed based on research in an animal model system. That showed that the neuromodulators released by efference from that animal's brain can accelerate or retard the potentials produced by visual stimulation of that animal's photoreceptors. Such a possibility has never been considered in human behavioral research even though it has been clearly demonstrated that attention can alter the temporal window of visual perception. We therefore propose that attention theory should include new top-down and bottom-up components (TBC) with a top-down component that involves efferents that go from the brain to the photoreceptors and a bottom-up component that involves consequent neuromodulatory alterations of the timing of the afferent photoreceptor potentials evoked by light stimuli. Not long ago, it would have been infeasible to test the validity of TBC in humans. However, newly developed multifocal electroretinogram (mfERG) technology makes it possible to obtain comfortable and objective measures of the timing of human retinal potentials while obtaining quantitative behavioral measures of both the observer's state of attention and of visual performance. If the present prediction is confirmed by such measures, it would allow the mfERG technique to be used for both the objective diagnosis of and the quantitative evaluation of treatments for a variety of attention disorders. These would include attention deficit hyperactivity disorders as well as several psychoses that involve attentional difficulties. The costs of testing TBC are modest; the potential benefits of applying this neurocomputational technology to assist sufferers could be substantial. [ABSTRACT FROM AUTHOR]

Purpose: To describe findings of spectral domain optical coherence tomography (SD-OCT) in the diagnosis of occult macular dystrophy (OMD). Materials and Methods: Five visually disturbed patients who had shown normal findings in full field electroretinogram (ERG), fundus photography and fluorescein angiography but abnormal findings in multifocal ERG had undergone SD-OCT. The morphologic changes in retina and macular thickness were detected and imaged by SD-OCT. We analysed the results of SD-OCT including macular thickness, inner segment and outer segment (IS /OS) boundary and external limiting membrane (ELM). Results: Mean age was 41.6 (22-63) in three male and two female patients in this study. Mean central foveal thickness was 142.9 (76-161) lm. All patients had shown decreased bowing of IS /OS boundary, and five of nine eyes were noted with disrupted IS /OS boundary of the photoreceptors according to SDOCT. The interruption of external limiting membrane was noted in three of nine eyes. Conclusions: Spectral domain optical coherence tomography findings are useful in diagnosing OMD. Morphologic changes of the retina including deformity of the OS/ IS boundary of the photoreceptors, disruption of the ELM and decreased foveal thickness may be important characteristics to consider when determining the pathophysiology and diagnosing criteria of OMD. [ABSTRACT FROM AUTHOR]

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This study aims to ascertain the characteristics of the response triggered by the global flash multifocal electroretinogram (MOFO mfERG) under various combinations of global and focal flash luminance, and to determine the optimal conditions for this measurement. Ten normal subjects with mean age 23.2 yrs (± 1.14 yrs) were recruited for the MOFO mfERG measurement. The visual stimulation consisted of four video frames (stimulus frame with 103 scaled hexagonal focal flashes, followed by a dark frame, a global flash and then another dark frame). The focal and global flash intensities were varied independently for four levels (50, 100, 200 and 400 cd/m2). The subjects then underwent measurements with sixteen combinations of focal and global flash luminance. The direct component (DC) and induced component (IC) of the MOFO mfERG were grouped into central and peripheral regions for analysis. The central and peripheral DC amplitude increased with the focal flash luminance under constant global flash luminance. Moreover, the proportion of the global flash and focal flash intensity was shown to be important to achieve an optimal IC response. When the ratio of global flash luminance to focal flash luminance (g/f ratio) was kept at about 2:1, the central and peripheral IC amplitude reached the peak value, and further increasing the global flash luminance would not enhance the IC response magnitude. The implicit time of both central and peripheral DC generally decreased with the increase of g/f ratio. However, the implicit time of central and peripheral IC increased with the g/f ratio. The g/f ratio is important in the MOFO mfERG paradigm, since the DC and IC responses change with this ratio. In order to obtain both optimal DC and IC responses, a g/f ratio of 1:1 with focal flash luminance between 100 cd/m2 and 200 cd/m2 would be recommended. As the global flash mfERG paradigm is studying the interaction triggered by both flashes, the g/f ratio is a vital parameter for measurement in future studies. [ABSTRACT FROM AUTHOR]

With an ageing population, the number of age-related macular disease (ARMD) cases will inevitably rise. This gives greater impetus for the need to identify the disease earlier and assess treatments to slow disease progression. Differing electroretinogram (ERG) modalities have been reviewed in relation to the objective assessment of retinal function in ARMD and for monitoring the effectiveness of clinical interventions. Conflicting results have been found with regard to the efficacy of ERG findings in the investigation of ARMD in previous years. The newer multifocal ERG paradigm provides spatial topographical information about retinal function in ARMD. It has shown promising results in monitoring effectiveness of clinical interventions and studies are continuing in this area. Better knowledge of retinal function in ARMD may lead to enhanced treatments at each phase of the disease. [ABSTRACT FROM AUTHOR]

Abstract: The spatial variation in central retinal function determined from mfERG was compared to co-localised measurements of cone density in two normal subjects. Individual cone cells in the parafoveal region of the retina were identified from 1°×1° images of the photoreceptor mosaic using a modified Heidelberg retina tomograph (HRT). The variation in cone density compared well with previous histology and retinal imaging studies and was strongly linearly correlated (r =0.98, p <0.001) with mfERG amplitude within the central retina. Retinal function determined from mfERG amplitude appears to directly reflect the density of the cone cells in this region. [Copyright &y& Elsevier]

Abstract: The current clinical analysis of the multifocal electroretinography (mfERG) recordings for detecting glaucoma is based on standard signal morphology, measuring amplitudes and latencies. However, this analysis is not sensitive enough for detection of small changes in the multifocal electroretinogram signals. Other, more sophisticated, analysis methods should be explored to improve the sensitivity of this diagnostic technique, such as the discrete wavelet transform, proposed in this paper. We present an alternative method for the detection of open angle glaucoma based on the characterization of global flash mfERG signals. The digital signal processing technique is based on wavelets, hitherto unused in this field, for detection of advanced-stage glaucoma. Two markers were obtained from the recorded signals by applying the discrete wavelet transform, which help discriminate healthy from glaucomatous signals. [Copyright &y& Elsevier]

The purpose of this study was to evaluate the relationship between elevations of intraocular pressure (IOP) and the multifocal electroretinogram (mfERG) in non-human primates. Experimental glaucoma was induced in 4 rhesus and 4 cynomolgus monkeys by laser trabecular meshwork destruction (LTD) in one eye. To evaluate the contribution of ganglion cells to mfERG changes, one monkey of each species had previously underwent unilateral optic nerve transection (ONT). After ≥44 weeks of elevation, the IOP was reduced by trabeculectomy in 2 non-transected animals. In the intact (non-transected) animals, there was an increase in the amplitude of the early mfERG waveforms (N1 and P1) of the first-order kernel (K1) throughout the period of IOP elevation in all of the rhesus, but not all of the cynomolgus monkeys. A species difference was also present as a decrease of the second-order kernel, first slice (K2.1) in all of the cynomolgus monkeys but only in 1 of the rhesus monkeys (the 1 with the ONT). Similar IOP effects on the mfERG were seen in the ONT animals. Surgical lowering of IOP resulted in a return of the elevated K1 amplitudes to baseline levels. However, the depressed K2.1 RMS in the cynomolgus monkeys did not recover. These results demonstrate species-specific changes in cone-driven retinal function during periods of elevated IOP. These IOP-related effects can occur in the absence of retinal ganglion cells and may be reversible. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the visual defects associated with the antiepileptic drug vigabatrin (VGB). Two hundred four people with epilepsy were grouped on the basis of antiepileptic drug therapy (current, previous, or no exposure to VGB). Groups were matched with respect to age, gender, and seizure frequency. All patients underwent objective assessment of electrophysiological function (wide-field multifocal electroretinography) and conventional visual field testing (static perimetry). Bilateral visual field constriction was observed in 59% of patients currently taking VGB, 43% of patients who previously took VGB, and 24% of patients with no exposure to VGB. Assessment of retinal function revealed abnormal responses in 48% of current VGB users and 22% of prior VGB users, but in none of the patients without previous exposure to VGB. Bilateral visual field abnormalities are common in the treated epilepsy population, irrespective of drug history. Assessment by conventional static perimetry may neither be sufficiently sensitive nor specific to reliably identify retinal toxicity associated with VGB. [Copyright &y& Elsevier]

Background: To investigate the outer and inner retinal function in patients with multiple evanescent white dot syndrome (MEWDS). Methods: The retinal function of three subjects with MEWDS was investigated using one or a combination of full-field electroretinography (ERG), multifocal electroretinography (mfERG) or recording of multifocal oscillatory potentials (mfOP). Results: In case 1, the scotopic, maximal, photopic and flicker ERG responses of the two eyes were similar but the amplitudes of the dark- and light-adapted OPs were markedly reduced in the affected eye. In cases 2 and 3, the ERG responses were grossly reduced in amplitude and as expected the OPs were also diminished. However, using the mfERG a residual area of ‘normal’ retinal function in the affected eye was identified. The local OP, assessed by the mfOP, within the residual ‘normal’ retinal area was reduced as compared with the corresponding retinal area of the fellow unaffected eye. Subsequently, the mfERG responses of the ‘normal’ retinal area were also reduced. Conclusion: The OPs were reduced throughout the retina in patients with MEWDS, even in the area with a normal mfERG. The electrophysiological findings suggest that functional abnormality in MEWDS may occur initially in the inner retina and subsequently involves the outer retina. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate changes in retinal morphology and visual function after transplantation of human fetal neuroretina and retinal pigment epithelium (RPE) in a minipig model of light-induced retinal degeneration. Methods: Photoreceptor degeneration was induced by 2500 lux white light exposure for six months in 16 minipigs. Human fetal (12-24 week) neuroretina and RPE were transplanted into the subretinal space adjacent to the central retina in 25 eyes. Sham operation was performed in three eyes. The operated eyes were examined by multifocal electroretinogram (mfERG), fundus fluorescence angiography (FFA), and histology for up to 12 months. Results: Subretinal transplantation of neuroretina and RPE was successful in 15 out of 25 eyes (60%), among which 10/15 eyes showed evidence of the grafted tissue in subsequent histology. Structural processes between the graft and host tissue were observed from one month post implantation, accompanied by increased numbers of GFAP-positive cells over time. Immunohistochemistry showed the presence of GFAP- and Chx10-positive cells, but rhodopsin staining was not observed within the grafted tissue. In 15 eyes, mfERG revealed retinal functional improvement in regions both inside and outside of the grafted area, but this was not observed in sham-operated eyes. FFA showed no vascular leakage or inflammatory cells in eyes receiving tissue transplants. Conclusions: Following subretinal transplantation, the grafted fetal neuroretina and RPE can survive for up to 12 months without signs of graft rejection, and the host retinas showed functional improvement over the same period. Our data suggest that subretinal transplantation of neuronal retina and RPE might be beneficial in improving retinal function in cases of retinal degeneration. [ABSTRACT FROM AUTHOR]

Abnormal electroretinogram (ERG) findings are essential to the diagnosis of acute zonal occult outer retinopathy (AZOOR), however, the standard Ganzfeld-ERG can record only the mass retinal response. The multifocal electroretinogram (mfERG) can simultaneously evaluate the local function of numerous small retinal areas. A neuro-ophthalmologic examination including visual field, ERG, and mfERG was performed in two patients with presumed AZOOR. Two patients showed a normal response to the standard ERG and an abnormal response to mfERG. In conclusion, the mfERG may be essential in the diagnosis of AZOOR. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia type 1 (SCA-ATXN1) is an autosomal dominant, neurodegenerative disease, caused by CAG repeat expansion in the ataxin-1 gene (ATXN1). In isolated reports of patients with neurological signs [symptomatic patients (SP)], macular abnormalities have been described. However, no reports exist about macular anomalies in SCA1 subjects carrying the ATXN1 mutation without neurological signs [not symptomatic carriers (NSC)]. Therefore, the main aim of our work was to evaluate whether the macular functional and morphological abnormalities could be detectable in SP, genetically confirmed and with neurological signs, as well as in SCA-ATXN1-NSC, harboring pathogenic CAG expansion in ATXN1. In addition, we investigated whether the macular involvement could be associated or not to an impairment of RGCs and of their fibers and of the neural conduction along the visual pathways. Herein, nine SCA-ATXN1 subjects (6 SP and 3 NSC) underwent the following examinations: visual acuity and chromatic test assessments, fundus oculi (FO) examination, macular and peripapillary retinal nerve fiber layer thickness (RNFL-T) analysis by Spectral domain-Optical Coherence Tomography (Sd-OCT) acquisition, multifocal electroretinogram (mfERG), pattern reversal electroretinogram (PERG) and visual evoked potentials (VEP) recordings. In four eyes of two SP, visual acuity reduction and chromatic abnormalities were observed; in three of them FO changes associated with macular thinning and outer retinal defects were also detected. In three NSC eyes, slight FO abnormalities were associated with qualitative macular morphological changes. By contrast, abnormal mfERG responses (exclusively from foveal and parafoveal areas) were detected in all SP and NSC (18 eyes). No abnormalities of PERG values, RNFL-T, and VEP responses were found, but in one SP, presenting abnormal papillo-macular bundle neural conduction. Results from our SCA-ATXN1 cohort suggest that a macular dysfunction, detectable by mfERG recordings, may occur in the overt disorder, and unexpectedly in the stage of the disease in which there is still an absence of neurological signs. In NSC, an exclusive dysfunction of preganglionic macular elements can be observed, and this is associated with both normal RGCs function and neural conduction along the visual pathways. [ABSTRACT FROM AUTHOR]

This paper describes optical coherence tomography (OCT) and the multifocal electroretinogram (mfERG), two recently available examination modes. Some of the limitations and disadvantages of using the techniques are discussed. The utility and scope of the techniques in diagnosis and assessment of some aspects of glaucoma are compared. OCT provides structural information and is fast, requiring no preparation of the patient; the output is immediately available. Current measurements of macular or peripapillary thickness provide useful quantitative data to assist in diagnosis and in monitoring the progress and any treatment of eye disease. New outputs may provide more sensitive methods of diagnosis than those currently available but it is important that such methods are carefully validated. mfERG takes longer to perform than OCT, requires preparation of the patient and the output may not be immediately available. Some outputs are complex and may require expertise in interpretation, which is not available to the average practitioner. Typically, mfERG systems are available only in specialist centres where research is carried out and where patients are referred for evaluation. It is likely that the procedures of the mfERG are so time consuming and complex that they will never reach the level of the general practitioner. Many mfERG protocols have not been widely used and there is scope for application of these protocols in spatial, temporal and contrast domains to improve the way in which they discriminate normal from abnormal visual systems. Until protocols have been standardised and their use is widespread, the findings from such reports should be viewed with a degree of caution. Currently, OCT is more widely accepted and more useful than the mfERG for evaluation of glaucoma and a wide range of other ocular defects. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: The aim of this study was to obtain a better understanding of the cellular contributions to the porcine global flash mfERG by using a pharmacologic dissection method, together with the method using variation of stimulus contrast which has been used to demonstrate mfERG changes in human glaucoma. Methods: Global flash mfERGs with different stimulus-contrast settings (99%, 65%, 49% or 29%) were recorded from 14 eyes of ten 6-week-old Yorkshire pigs in control conditions and after suppression of inner retinal responses with inhalation of isoflurance (ISO), and injections of tetrodotoxin (TTX) and N-methyl-d-aspartic acid (NMDA). ON- and OFF-pathway responses were isolated by injection of 2-amino-4-phosphonobutyric acid (APB) and cis-2,3-piperidinedicarboylic acid (PDA). Results: The porcine global flash mfERG consisted of an early direct component (DC) and a late induced component (IC). ISO and TTX removed inner retinal contributions to the IC; NMDA application further abolished the oscillatory wavelets in the DC and removed the residual IC waveform. The inner retina contributed regular oscillation-like wavelets (W1, W2 and W3) to the DC and shaped the IC. After removing the inner retinal contributions, the porcine global flash mfERG waveform becomes comparable to that obtained with conventional mfERG stimulation. The remaining waveform (smoothed DC) was mainly contributed by the ON- and OFF-bipolar cells as revealed after APB or PDA injection. Photoreceptors contributed a small signal to the leading edge of N1. The characteristic of contrast response function of DC was demonstrated to be contributed by the inner retinal oscillation-like wavelets. Conclusion: We believe that the DC of the porcine global flash mfERG is mainly composed of contributions from photoreceptors, and ON- and OFF-bipolar cells, where inner retinal activity partially shaped the DC with superimposed regular wavelets. However, the IC is dominated by inner retinal activity. The contrast response functions of DC consisted of both outer retinal response and oscillation-like wavelets of the inner retinal response. Both contain different characteristics during contrast modulation of the stimulus, where the changes of W2 of the inner retinal response seem independent of contrast modulation. The DC contrast response feature depends mainly on the relative contribution of inner retinal activities; the loss of inner retinal cells may alter the DC contrast response function, making it tend toward linearity. [Copyright &y& Elsevier]

Abstract: We investigated relationships between retinal structure using optical coherence tomography (OCT) and retinal function using peripheral resolution acuity and multifocal electroretinograms (mfERG) in 56 subjects with a range of refractive errors (+0.50 to −15.00D). Retinal thinning occurred in moderate and high myopia which appeared to be primarily due to reduced thickness of the middle to inner retina (MIR) (outer plexiform layer to the nerve fiber layer). MIR thickness was correlated with reduced spatial resolution and delayed mfERG timing in the peripheral retina. The findings suggest the structure and function of the post-receptor retina is susceptible to disruption in moderately and highly myopic eyes. [Copyright &y& Elsevier]

Abstract: Background: Hydroxychloroquine sulfate (Plaquenil; Sanofi-Aventis, Bridgewater, New Jersey) is an antimalarial agent, which is sometimes used for the treatment of certain autoimmune disorders. Its use has been associated with ocular side effects; the most concerning is toxic maculopathy. Case report: A 71-year-old arthritic white woman requested a second opinion regarding retinal Plaquenil toxicity. The patient℉s history was significant for seronegative rheumatoid arthritis diagnosed 6 years prior. She had taken Plaquenil 400 mg a day for about 5 years but had discontinued the drug 6 months before when bilateral central scotomas were first noted. At the consultation visit, her visual acuities were 20/20 in both eyes. SITA-Standard 10-2 disclosed a dense scotoma with 4° of central sparing in each eye. Fundus examination found retinal pigment epithelium changes bilaterally; no “bull℉s eye” retinopathy was observed. Conclusion: Withdrawal of the medication is the only effective treatment for Plaquenil toxicity and, even then, the toxic effects may progress because of the slow clearance of the drug. Though controversy exists regarding screening recommendations, a baseline ophthalmic examination should be performed on all patients before initiating Plaquenil. If a patient is considered low risk, examinations can be scheduled annually. For high-risk patients, 6-month progress visits are strongly recommended. [Copyright &y& Elsevier]

Abstract: Visual sensitivity improves with prolonged exposure to light. Global neuroretinal responses increase, but little is known about the dynamics of local retinal responses over brief time intervals after changes in light level. This study applies the time-slice multifocal electroretinogram (TS mfERG) paradigm for the measurement of local electrical responses of the human eye over brief time intervals. Sixty-one, localised retinal areas were assessed over 25° of the visual field. Cone-mediated contributions to the time-slice waveform were established. The time-slice mfERG waveforms were similar in shape and timing for pre- and post-photopigment bleach conditions after saturation of rod-mediated responses, suggesting there was no rod-mediated intrusion in the waveform. The temporal dynamics of the mfERG components show that N1P1 amplitudes decrease with each successive time-slice probe, with larger amplitude responses in the central retina compared to nasal and temporal retina. The time-slice mfERG waveform is a technique for assessing the temporal dynamics of cone-generated neural responses over time. The data are interpreted in terms of the vascular supplies and lower-level visual adaptation mechanisms. [Copyright &y& Elsevier]

The article reports on the case of a 19-year-old Japanese woman who was presented with decreased vision and photopsia of the left eye. She has been diagnosed with unilateral cone dysfunction (UCD) who later developed acute zonal occult outer retinopathy (AZOOR) in the contralateral eye. The results indicate that the UCD is one of the clinical manifestations of AZOOR.

The multifocal electroretinogram (mfERG) is a newly developed electrophysiological technique. In this paper, a classification method is proposed for early diagnosis of the diabetic retinopathy using mfERG data. MfERG records were obtained from eyes of healthy individuals and patients with diabetes at different stages. For each mfERG record, 103 local responses were extracted. Amplitude value of each point on all the mfERG local responses was looked as one potential feature to classify the experimental subjects. Feature subsets were selected from the feature space by comparing the inter-intra distance. Based on the selected feature subset, Fisher's linear classifiers were trained. And the final classification decision of the record was made by voting all the classifiers' outputs. Applying the method to classify all experimental subjects, very low error rates were achieved. Some crucial properties of the diabetic retinopathy classification method are also discussed. [ABSTRACT FROM AUTHOR]

This manuscript focuses on the pathogenesis of age-related maculopathy (ARM) and the documentation of new treatments in ARM. Ischaemia will be given special consideration, as it is believed to play a central role in both early ARM and late ARM or age-related macular degeneration (AMD). Reduced choroidal and retinal blood flow causes ischaemia of Bruch’s membrane, retinal pigment epithelium and neuroretina in the early course of ARM. This is thought to be the primary trigger of the condition. Chronic ischaemia upregulates vascular endothelial growth factor (VEGF), which induces abnormal vessel growth in neovascular AMD. The role of ischaemia in neovascular AMD is supported by the evidence of effective new treatments targeting VEGF. [ABSTRACT FROM AUTHOR]

Abstract: Objective: This study investigated neuroretinal activity under normoxic and hypoxic conditions with the multifocal electroretinogram (mfERG). Methods: We used two mfERG paradigms, the fast flicker and slow flash stimulation modes, to measure neuroretinal activity in five healthy participants who breathed room air and a reduced oxygen mixture (14% oxygen, balance nitrogen). We analysed concentric ring N1P1 and P1N2 response density amplitudes, the P1 implicit times as well as the local scalar product (SP) response densities. Results: During hypoxia there was a significant reduction of the scalar product response density for the fast flicker (p <0.001) and for the slow flash mfERG (p <0.001). The N1P1 and P1N2 response densities were lower especially for the central three rings; although these reductions were not significant between the two oxygen conditions, they indicated an overall distortion of the mfERG waveform. Conclusions: It is demonstrated that a postreceptoral, primarily ON and OFF bipolar cell deficit is evident in the central retina of healthy young people during short term hypoxia. Significance: Our findings suggest that persons with pre-existing ischaemic eye disease may be at risk when exposed to hypoxic conditions. [Copyright &y& Elsevier]

A 24-year-old female patient suffering from hearing loss of the right ear, bilateral visual field defects, memory loss, and ataxia was examined using kinetic and static threshold perimetry, fluorescein angiography, indocyanine green angiography, and electrophysiological examinations. The observation period covered 18 months. The patient was diagnosed as having Susac syndrome. Worldwide, fewer than 100 cases have been reported. Until now, a proven therapy has been lacking. This patient improved in terms of static threshold visual fields and multifocal electroretinogram after therapy with intravenous immunoglobulins, intravenous high-dose corticosteroids, aspirin, and nimodipine. [ABSTRACT FROM AUTHOR]