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Thomas Kaercher,1 Elisabeth M Messmer,2,3 Thomas Berninger,4 Klaudia K Huber-van der Velden,5 Raphaela Geiger,6 Pauline Cipriano-Bonvin,7 Christina Jacobi8,9 1Augenarztpraxis, Heidelberg, Germany; 2Department of Ophthalmology, Ludwig-Maximilian-University, Munich, Germany; 3Praxis Professor Kampik & Kollegen, Munich, Germany; 4Augenzentrum, Olching, Germany; 5Augenheilkunde Lindenthal, Köln-Lindenthal, Germany; 6TRB Chemedica AG, Feldkirchen, Germany; 7TRB Chemedica International SA, Geneva, Switzerland; 8Augen & Haut Zentrum-Praxis Dr. Jacobi, Nuremberg, Germany; 9Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, GermanyCorrespondence: Thomas Kaercher, Augenarztpraxis, 48 Dossenheimer Landstr, Heidelberg, 69121, Germany, Tel +49 6221 400 888, Fax +49 6221 412 203, Email thomas.kaercher@meibomius.dePurpose: To investigate the efficacy, safety and tolerability of topical omega-3 polyunsaturated fatty acids (PUFA) as an innovative treatment of dry eye disease (DED).Patients and Methods: In a pilot, multicenter, masked-observer, randomized, active-controlled, non-inferiority study in Germany, patients self-treated their eyes with daily instillations of eye drops containing either omega-3 PUFA or povidone as major components for three months. At four and twelve weeks, efficacy was among others evaluated based on Ocular Surface Disease Index (OSDI), ocular surface symptoms intensity, general clinical impression, tear break-up time (TBUT), corneal fluorescein staining using the Oxford grading scale, tear volume, and matrix metalloproteinase-9 (MMP-9) concentration in the tear film. Safety evaluation included visual acuity, intraocular pressure, and the incidence of adverse events. Co-primary endpoints were the mean percent changes from baseline of TBUT and OSDI after four weeks.Results: In total 80 patients were included, of whom 37 in the PUFA group and 39 in the povidone group were evaluable for the co-primary endpoints. Patients had a mean age of 52 years and > 80% were women. Both co-primary endpoints (TBUT and OSDI) significantly improved from baseline in both treatment groups, at Week 4 and Week 12 and the statistical analysis demonstrated topical omega-3 PUFA to be non-inferior to 2% povidone for these two parameters. Both treatments resulted in a significant improvement of most secondary efficacy endpoints as well, often with a slight difference in favor of PUFA, not reaching statistical significance though. One non-severe, treatment-related local AE was reported in each group.Conclusion: Omega-3 PUFA-based eye drops proved to be non-inferior to povidone-containing eye drops in the treatment of signs and symptoms of dry eye. This treatment may thus be an additional tool for the management of DED.Keywords: polyunsaturated fatty acids, povidone, dry eye disease, artificial tears, omega-3 fatty acid

Aim: To investigate the relative sensitivity and specificity of two tests of retinal function (the electro-oculogram (EOG) and a computerised colour vision test) in screening for ocular toxicity caused by [...]

Aims Producing dry, zeolite-based granular and powder inoculants of the Gram-negative, plant growth-promoting bacterium Paraburkholderia phytofirmans Ps JN. Key aspects were maintenance of cell viability during desiccation and throughout storage at ambient conditions. Methods and Results Twenty additives and exopolysaccharide ( EPS) produced by Ps JN were screened for conserving cell viability of Ps JN in air-drying and lyophilization. Suitable combinations (e.g. skimmed milk + air-drying) increased survival of Ps JN up to 100 000-fold and maintained it for >7 months. EPS performed as good as skimmed milk during air-drying, but was second-rank regarding shelf life. Combinations of zeolite, skimmed milk and gelatin as a film-forming agent were extruded and processed into granules and powders, both displaying relatively stable viability for over 4 weeks at ambient conditions. Gelatin promoted brittleness of zeolite-based inoculants. Conclusions Viability of highly sensitive Ps JN was successfully conserved in dry formulations, taking into account the interplay between carrier, protectants, drying method and coating agent. Significance and Impact of the Study This is the first study to provide ways of maintaining viability of Ps JN during desiccation stress and to investigate the applicability of its EPS as a protectant, thus ultimately facilitating successful plant inoculation especially under field conditions. [ABSTRACT FROM AUTHOR]

Ophthalmic and neurological complications are frequent findings in patients with AIDS. Little is known about neuroretinal dysfunction in patients with HIV infection. The purpose of this study was to measure and evaluate colour vision in patients with HIV infection or AIDS. Colour contrast sensitivity tests were performed on 75 patients (150 eyes) in different stages of HIV infection. A highly sensitive computer graphics system was used to measure tritan, deutan, and protan colour contrast thresholds. Patients were classified into three clinical groups: (a) asymptomatic HIV infection, (b) lymphadenopathy syndrome or AIDS-related complex, and (c) AIDS. Overall, tritan (p < 0.0001), deutan (p = 0.003), and protan (p = 0.009) colour contrast sensitivities were significantly impaired in patients with HIV infection compared with normal controls. Colour thresholds in patients with asymptomatic HIV infection (mean tritan threshold: 4.33; deutan: 4.41; protan: 3.97) were not impaired compared with normal controls. Colour vision was slightly impaired in patients with lymphadenopathy syndrome or AIDS-related complex (tritan: 6.25 (p < 0.0001); deutan: 4.99 (p = 0.02); protan: 4.45 (p = 0.05)). In patients with AIDS the impairment was even more marked (tritan: 7.66 (p < 0.0001); deutan: 5.15 (p < 0.0009); protan: 4.63 (p = 0.004)). Analysis of covariance controlling for age demonstrated a close association between impairment of tritan colour contrast sensitivity and progression of HIV disease (p < 0.0001). Following Köllner's rule, our study suggests that neuroretinal dysfunction occurs in patients with symptomatic HIV infection or AIDS. This is emphasised by the finding that the relative impairment in tritan vision compared with deutan/protan vision might reflect the difference in the number of cones or receptive fields. Measurement of tritan colour contrast sensitivity appears to be an appropriate and easily applicable method to detect early neuroretinal dysfunction in patients with HIV disease. [ABSTRACT FROM PUBLISHER]

A typical finding in dominant infantile optic atrophy (DIOA) is the variation of the phenotypic expression of the DIOA gene even within one family. It is of special interest for genetic consultation to evaluate an examination method for detecting subclinically involved patients. Seven patients of two families were examined. Three of them had the typical symptoms of DIOA: reduced visual acuity, tritan defect, temporal pallor of both optic discs, and a relative central scotoma for white test spots. In visual evoked cortical potentials (VECP) the amplitudes were reduced, and in one patient the latencies were slightly delayed and two patients considerably so. The amplitude of the negative component of the PERG was markedly reduced, while the positive component was normal. In the remaining four family members normal retinal and cortical responses were recorded under standard conditions and visual fields and colour vision (FM 100 hue) were also normal. However, static perimetry with blue test spots showed in two family members enlarged central scotomas, thus proving that they had subclinical DIOA. [ABSTRACT FROM PUBLISHER]

Single cell experiments in primates show that there are two major parallel pathways named after the lamination in the lateral geniculate nucleus. Each of these systems can be preferentially excited by appropriate stimuli. Here we report that in man the polarity of the evoked potentials both in retina and in cortex depends on which of these pathways is stimulated. The identification of the resulting waveforms is thereby simplified--a matter of practical importance. The fact that at retina and cortex there are characteristic potentials may reflect the different cell biology of the two pathways. [ABSTRACT FROM PUBLISHER]

We studied one patient with Leber's optic atrophy (LOA) in the acute stage and 12 at the chronic stage of the disease, and measured the activity of rhodanese in white blood cells and the level of cyanide in whole blood. In the patient with acute disease the blood cyanide level was significantly increased at first. Treatment of this patient with cyanide antagonists reduced his cyanide level, but this was not accompanied by improvement in visual function. Rhodanese activity was normal in all patients, as were the blood cyanide levels in each of the 12 patients at the chronic stage of the disease. These findings suggest a temporary disturbance of cyanide metabolism during the acute phase of the disease in this family. The abnormal metabolic mechanism was not identified. [ABSTRACT FROM PUBLISHER]

As awareness of the value of genetic counseling services increases, there has been greater recognition of the need to diversify service delivery into different languages. Studies within genetic counseling and related fields have identified complications that can arise from language nonconcordance between provider and patient. A strategy to mitigate language barriers is prioritizing the development of a multilingual workforce of genetic counselors (GCs) who can communicate with patients in their preferred language. This exploratory study assessed the experiences of multilingual GCs who have practiced in a clinical role with the aim to identify relevant challenges and differences when counseling in their nondominant language. Statistical analysis was performed to identify differences in session tasks and emotions experienced when counseling in one's nondominant language versus their dominant language. Data analysis identified an increase in reported difficulty level for most clinical tasks while using a nondominant language, most notably for difficulty with psychosocial counseling, disclosing results, and administrative tasks. Participants were also surveyed on employer support and resources provided. Overall, results suggest that multilingual GCs may benefit from greater support in certain areas within clinical roles to enhance their ability to provide patient care in their nondominant language., (© 2024 National Society of Genetic Counselors.)

Genetic counselors are an integral part of the healthcare system; however, the number of genetic counselors in many parts of the United States is limited, impacting access to comprehensive healthcare for all patients. One solution to addressing this deficit includes modifying genetic counseling training programs to increase student enrollment. Fieldwork capacity, driven by a limited number of rotation sites and supervisors, produces a significant bottleneck to entering the profession. Other professions have reported on techniques to increase fieldwork capacity; however, the practicality of these techniques for genetic counseling training has yet to be explored. This study seeks to investigate the perspectives of key stakeholders in genetic counseling training programs on the practicality of techniques already posited in the literature from other allied health professions. Semi-structured focus group interviews with 25 participants were conducted at the 2019 National Society of Genetic Counselors conference. Participants included program directors and supervisors from clinical, industry, and laboratory backgrounds. The focus group responses were analyzed using directed content analysis and a split coding technique, after which several themes emerged within the larger domains of rotation structures, systems infrastructure, skill-building methods, and other novel techniques to increase fieldwork capacity. Emerging themes included the importance of finding quality student placements rather than maximizing the quantity of participatory cases; a need for transparency about the transferability of skills learned from novel experiences; scaffolding student entrustment to expand supervisor capacity; and recognizing nuances in implementation for individual programs. Overall, the results emphasize the importance of openness in communication to manage expectations for students and supervisors, who may be more hesitant to try novel rotation placements and skill-building techniques. Genetic counseling programs may use these results to address the bottleneck of fieldwork capacity, increasing student enrollment., (© 2024 National Society of Genetic Counselors.)

Ethnic diversity is not reflected within healthcare professions, including genetic counseling, where lack of growth and membership among minority colleagues extends to upper-level and executive roles. While diversity and inclusion-based topics have been emphasized, studies on potential barriers to career advancement in the field of genetic counseling have not received the same attention. Our study examined the current state of mentorship and sponsorship programs, the presence of diversity and inclusion initiatives, and opportunities for career advancement through the lens of a minority genetic counselor. Practicing genetic counselors in the United States identifying as part of any racial group, other than non-Hispanic White alone, were recruited through the Minority Genetics Professionals Network for survey participation. A 31-item survey was fully completed by 19 practicing genetic counselors from a variety of ethnic backgrounds. Data were analyzed using descriptive statistics and thematic analysis, allowing for individual stories and accounts to be amplified. Results showed 16 of 19 participants had never been promoted in their current employment setting. Additionally, 7 out of 19 respondents disagreed or strongly disagreed that their company had a commitment to an ethnically diverse workforce within upper-level positions. Prominent themes identified from open-ended responses included lack of social connection with supervisors and the cross-race effect, a term referencing a tendency for individuals to better recognize members of their own race or ethnicity than others. Additional themes revealed feelings of isolation, need for support from White colleagues, as well as desired emphasis on sponsorship tailored toward professional growth. These findings demonstrate a need for proactive involvement in reaching ethnic and racial minority genetic counselors through companywide policy efforts, support and advocacy from White colleagues, and modification of cultural perception frameworks. Further focus and emphasis on these distinct but critical topics may be important in promoting increased diversity in upper-level positions in the field of genetic counseling., (© 2022 National Society of Genetic Counselors.)

Conscience clauses are laws that allow healthcare providers to refuse to participate in legal medical services based on moral or ethical objections. Genetic counselors encounter a variety of ethical and moral issues, including counseling about abortions. Currently, three states (Oklahoma, Nebraska, and Virginia) have genetic counseling conscience clause laws that allow genetic counselors to refuse to counsel about abortions. Conscience clause laws applying to physicians and pharmacists have been studied; however, they have not been studied in genetic counseling to date. We conducted an exploratory study assessing conscience clause awareness, attitudes, perceived obligations if utilizing a conscience clause, and alignment with the National Society of Genetic Counseling (NSGC) Code of Ethics. Genetic counselors (n = 274) currently practicing in the United States completed an online survey recruited through the NSGC listserv. The majority of participants were not aware that conscience clauses exist for genetic counseling (90%). There was uncertainty about whether genetic counselors had the right to utilize a conscience clause in practice (24% said yes, 31% said no, and 45% were unsure/needed more information). The majority reported an obligation to refer a patient if implementing a conscience clause (90%), although there were discrepancies among what constitutes an appropriate referral. When asked about the interaction between conscience clauses and the NSGC Code of Ethics, 45% believe they are separate and one does not supersede the other, 31% felt the Code of Ethics supersedes, 8% felt conscience clauses supersede, and 16% were unsure. Our study shows overall uncertainty with how conscience clause laws may be applied in clinical practice. Further clarity and education, especially in states where these laws exist, is critical to navigate the interaction between conscience clause laws and genetic counseling practice., (© 2021 National Society of Genetic Counselors.)

Water-soluble polymers (WSPs) are a versatile group of chemicals used across industries for different purposes such as thickening, stabilizing, adhesion and gelation. Synthetic polymers have tailored characteristics and are chemically homogeneous, whereas plant-derived biopolymers vary more widely in their specifications and are chemically heterogeneous. Between both sources, microbial polysaccharides are an advantageous compromise. They combine naturalness with defined material properties, precisely controlled by optimizing strain selection, fermentation operational parameters and downstream processes. The relevance of such bio-based and biodegradable materials is rising due to increasing environmental awareness of consumers and a tightening regulatory framework, causing both solid and water-soluble synthetic polymers, also termed 'microplastics', to have come under scrutiny. Xanthan gum is the most important microbial polysaccharide in terms of production volume and diversity of applications, and available as different grades with specific properties. In this review, we will focus on the applicability of xanthan gum in agriculture (drift control, encapsulation and soil improvement), considering its potential to replace traditionally used synthetic WSPs. As a spray adjuvant, xanthan gum prevents the formation of driftable fine droplets and shows particular resistance to mechanical shear. Xanthan gum as a component in encapsulated formulations modifies release properties or provides additional protection to encapsulated agents. In geotechnical engineering, soil amended with xanthan gum has proven to increase water retention, reduce water evaporation, percolation and soil erosion - topics of high relevance in the agriculture of the 21st century. Finally, hands-on formulation tips are provided to facilitate exploiting the full potential of xanthan gum in diverse agricultural applications and thus providing sustainable solutions., (© 2021 Jungbunzlauer Ladenburg GmbH. Microbial Biotechnology published by Society for Applied Microbiology and John Wiley & Sons Ltd.)

In response to mounting concerns regarding a perceived shortage of genetic counselors, the Genetic Counselor Workforce Working Group (WFWG) was established in 2013 to identify barriers to growth of the genetic counseling workforce. After completing a workforce analysis and confirming a shortage, the WFWG convened a strategic planning session in 2017 to identify goals and strategies that would increase the number of certified counselors to meet the current and future workforce demands and ensure access to genetic counselor services. Subcommittees were formed and charged with achieving assigned goals; one such subcommittee included a curriculum working group to build a dynamic and effective educational infrastructure to increase the number of genetic counselors graduated from accredited training program. This paper reports of progress of the WFWG Curriculum Subcommittee toward achieving this goal through a narrative literature review that identifies innovative education methods that help to increase capacity of fieldwork training, both in genetic counseling training programs and in other health professions. Of the five thematic areas identified in this study, four are analyzed for insight into building clinical capacity: systems/infrastructure, rotation structure/models, skill building, and novel techniques. While additional studies are needed to establish best practices in these thematic areas, there are several take-aways that training programs can begin to utilize as they look to expand training opportunities. While growth of the genetic counseling workforce will continue to be a long-term issue, programs should begin to think creatively and innovatively about how to reach beyond traditional fieldwork training formats to build capacity. The strategies explored in this paper offer feasible and untapped solutions that can help support efforts to establish a sustainable genetic counseling workforce., (© 2020 National Society of Genetic Counselors.)

We sought to determine the costs of genetic testing and compliance with published guidelines and clinical best practices at our institution. A cost analysis was performed comparing the costs of ordered tests to the cost of the recommended testing. This was an approved quality improvement project at a tertiary teaching hospital in California. We identified charts associated with the genetic testing billing codes for common genetic tests through our contracted laboratory (cystic fibrosis genotyping, Breast cancer susceptibility gene (BRCA 1&2), Methylenetetrahydrofolate reductase (MTHFR), factor V Leiden (FVL), prothrombin gene pathogenic variant, alpha-thalassemia, hemochromatosis, and cell-free fetal DNA). Charts were reviewed retrospectively by a licensed, certified genetic counselor to assess the compliance with published clinical practice guidelines identified on GeneReviews and the American College of Obstetricians and Gynecologists (ACOG). Tests were classified as: appropriate, misordered/not indicated, misordered/false reassurance, and misordered/inadequate. We performed a cost analysis for the recommended test changes. We reviewed 114 charts over a three-month period. Forty-four (38.6%) of the tests were misordered based on published clinical practice guidelines: 24 (21%) were misordered/not indicated, 8 (7%) were misordered/false reassurance, and 12 (10.5%) were misordered/inadequate. Costs of ordered testing ($75,177) were compared to recommended testing after review ($54,265), with a total cost savings of $20,912. In clinical practice, over one-third of genetic tests reviewed were misordered. As these tests are a small fraction of all genetic tests at our institution, future studies should broaden the scope of testing evaluated to understand the magnitude of this problem and potential cost savings. Genetic counselor review and involvement in genetic test ordering can decrease inappropriate healthcare expenditures and improve patient care., (© 2020 National Society of Genetic Counselors. This article has been contributed to by US Government employees and their work is in the public domain in the USA.)

Herein, a biosensor based on a reduced graphene oxide field effect transistor (rGO-FET) functionalized with the cascading enzymes arginase and urease was developed for the detection of L-arginine. Arginase and urease were immobilized on the rGO-FET sensing surface via electrostatic layer-by-layer assembly using polyethylenimine (PEI) as cationic building block. The signal transduction mechanism is based on the ability of the cascading enzymes to selectively perform chemical transformations and prompt local pH changes, that are sensitively detected by the rGO-FET. In the presence of L-arginine, the transistors modified with (PEI/urease(arginase)) multilayers showed a shift in the Dirac point due to the change in the local pH close to the graphene surface, produced by the catalyzed urea hydrolysis. The transistors were able to monitor L-arginine in the 10-1000 μM linear range with a LOD of 10 μM, displaying a fast response and a good long-term stability. The sensor showed stereospecificity and high selectivity in the presence of non-target amino acids. Taking into account the label-free, real-time measurement capabilities and the easily quantifiable, electronic output signal, this biosensor offers advantages over state-of-the-art L-arginine detection methods., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Damages of the (agro)ecosystem by extensive use of chemical fertilizers and pesticides, the global dying of bee populations possibly linked to pesticide spraying, and stricter regulations for pesticide use together with successful use of microbials in IPM programs are pushing on the development and commercialization of new microbial products and a large and growing biostimulants and biocontrol market. This review focuses on microbial inoculants including bacteria, fungi, and viruses used as biostimulant or biocontrol agent for foliar application and covers all important steps from inoculant development to successful field application. Topics presented comprise typical spraying equipment including the importance of the spraying process and relating effects, furthermore formulation development including classification and adjuvants, and thirdly regulatory aspects as currently applied or under discussion. Microbial inoculants for foliar spray reported in scientific literature are summarized and contrasted with selected commercial products. Special attention is given to factors most important in microbial spray: (a) type of active ingredient (bacteria, fungi, viruses), (b) mode of action (ingestion, contact, competition), (c) interaction with the plant leaf surface, (d) droplet size in terms of microbe concentration and leaf coverage, and (e) environmental conditions during spraying. Finally, we want to emphasize that timely administration is of utmost importance for successful spraying and maximum efficacy. This might be supported by weather stations and disease/pest models as an important step towards precision farming.

The application of beneficial, plant-associated microorganisms is a sustainable approach to improving crop performance in agriculture. However, microbial inoculants are often susceptible to prolonged periods of storage and deleterious environmental factors, which negatively impact their viability and ultimately limit efficacy in the field. This particularly concerns non-sporulating bacteria. To overcome this challenge, the availability of protective formulations is crucial. Numerous parameters influence the viability of microbial cells, with drying procedures generally being among the most critical ones. Thus, technological advances to attenuate the desiccation stress imposed on living cells are key to successful formulation development. In this review, we discuss the core aspects important to consider when aiming at high cell viability of non-sporulating bacteria to be applied as microbial inoculants in agriculture. We elaborate the suitability of commonly applied drying methods (freeze-drying, vacuum-drying, spray-drying, fluidized bed-drying, air-drying) and potential measures to prevent cell damage from desiccation (externally applied protectants, stress pre-conditioning, triggering of exopolysaccharide secretion, 'helper' strains). Furthermore, we point out methods for assessing bacterial viability, such as colony counting, spectrophotometry, microcalorimetry, flow cytometry and viability qPCR. Choosing appropriate technologies for maintenance of cell viability and evaluation thereof will render formulation development more efficient. This in turn will aid in utilizing the vast potential of promising, plant beneficial bacteria as sustainable alternatives to standard agrochemicals., (© 2018 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.)

The microbial component of healthy seeds - the seed microbiome - appears to be inherited between plant generations and can dynamically influence germination, plant performance, and survival. As such, methods to optimize the seed microbiomes of major crops could have far-reaching implications for plant breeding and crop improvement to enhance agricultural food, feed, and fiber production. Here, we describe a new approach to modulate seed microbiomes of elite crop seed embryos and concomitantly design the traits to be mediated by seed microbiomes. Specifically, we discovered that by introducing the endophyte Paraburkholderia phytofirmans PsJN to the flowers of parent plants we could drive its inclusion in progeny seed microbiomes, thereby inducing vertical inheritance to the offspring generation. We demonstrated the introduction of PsJN to seeds of monocot and dicot plant species and the consequential modifications to seed microbiome composition and growth traits in wheat, illustrating the potential role of novel seed-based microbiomes in determining plant traits.

A range of lab-scale methods for encapsulation of plant growth-promoting bacteria in alginate beads intended for seed coating was evaluated: contact-spotting, extrusion through syringe with/without vibration, ejection by robotic liquid handler, extrusion by centrifugal force and commercial devices (nanodispenser, aerodynamically assisted jetting, encapsulator). Two methods were selected based on throughput (encapsulator: 1.5-5 mL/min; syringe with subsequent pulverisation: 5 mL/min). Four bead sizes (55 ± 39 μm, 104 ± 23 μm, 188 ± 16 μm and 336 ± 20 μm after lyophilisation) were produced. Bacterial viability, release, bead morphology, seed surface coverage and attrition were investigated. Release from the smallest bead size was approximately 10 times higher than from the largest. Seed surface coverage was highest (69 ± 3%) when alginate beads produced with nozzle size 80 μm were applied. Pulverised macro-beads are an alternative option, if high throughput is top priority.

Purpose: Optimal screening for ocular toxicity caused by chloroquine and hydroxychloroquine is still controversial. With the multifocal pattern electroretinogram (mfPERG), a new electrophysiological technique has recently become available to detect early changes of ganglion cells. In this study this new technique is applied to a series of 10 patients seen consecutively receiving long-term chloroquine medication., Methods: In 10 patients receiving chloroquine medication, clinical examination, Amsler visual field testing and computerized color vision testing were performed. If toxicity was suspected, automated perimetry was carried out. In addition, in all patients conventional pattern electroretinogram (PERG) and mfPERG testing were performed., Results: On clinical examination 8 patients showed no chloroquine-associated maculopathy, while 2 patients did. Of these 2, only 1 reported abnormalities when viewing the Amsler chart, while automated perimetry showed typical, ring-like paracentral scotomas in both affected patients and color vision was significantly abnormal. In the normal patients, 4 of 8 had a mild color vision disturbance, which correlated to age-related macular changes. The amplitudes of the PERG and the central (approximately 10 degrees ) responses of the mfPERG were markedly reduced in chloroquine maculopathy, while the latencies were unchanged. The peripheral rings of mfPERG (ranging to 48 degrees ) were not affected by chloroquine toxicity. Both PERG and mfPERG were less affected by age-related macular changes., Conclusions: The reduction of PERG and central mfPERG responses in chloroquine maculopathy may help with the early detection of toxicity., (Copyright 2004 S. Karger AG, Basel)

Background: The pattern ERG can be used to detect early glaucomatous change, because the response of cells in the inner retina from (typically) 20 degrees -40 degrees of area is reduced before perimetric abnormality is certain. The multifocal pattern electroretinogram (mfPERG) allows analysis of many local regions within this area. The aim of this study was to investigate whether in patients with presumed glaucoma the mfPERG permits diagnosis and discrimination from normals., Methods: Measurements on 25 age-related normal eyes were compared to those on 23 eyes with different stages of glaucoma. A RETIScan system was used to generate a stimulus pattern of 19 hexagons, each consisting of six triangles. The triangles pattern-reversed black to white at 75 Hz. Those 19 hexagons were grouped into three stimulus regions: a central field, a middle, and a peripheral ring. The complete array subtended 48 degrees at the eye. The hexagons alternated between black and white, in a temporal pattern that followed a corrected binary m-sequence (length 512, 10 cycles with 39 s each). The amplitudes and latencies of positive responses at approximately 50 ms (P-50) and negative responses at approximately 95 ms (N-95) were analyzed., Results: In patients with glaucoma the P-50 and N-95 components of the mfPERG were significantly reduced for the central area and both outer rings compared to normal volunteers (p<0.001, Mann-Whitney-U). The most distinct reduction was observed for N-95 and the central ring. Changes in latencies were not conclusive. The reduction of the components increased with the stage of glaucoma. A predictive model for detecting early glaucomatous changes was designed based on P-50-N-95 with 88% sensitivity and 76% specificity., Conclusion: In glaucoma a marked reduction of components, especially centrally is observed in the mfPERG. This hints to an early involvement of central ganglion cells and may be useful for future functional tests.

Purpose: To demonstrate the possibility of topographic mapping of retinal function under simultaneous control of fixation in humans, by scanning laser ophthalmoscope evoked multifocal electroretinography (SLO-m-ERG)., Methods: A confocal scanning laser ophthalmoscope was used as a stimulator and trigger unit to take m-ERGs. Short m-sequences based on a modified algorithm were used, with the advantage that each measurement cycle can be evaluated separately. We examined 78 normal subjects; in 62 a distortion factor of 1:1 was applied, and a factor of 1:4 in 16., Results: The recorded amplitudes decreased with eccentricity, approximately following the decrease of retinal cone density. Amplitudes were higher in the central hexagonal element in the group with 1:4 distortion than in the group with the 1:1 distortion setting., Conclusions: SLO-m-ERG is a reliable technique for topographic mapping of retinal function under simultaneous control of fixation.

Background: Mutations in the OA1 gene on the short arm of the X chromosome are known to cause X-linked ocular albinism (x1OA) in males. A four-generation family with this disorder, including asymptomatic carrier females, was investigated by molecular analysis of the OA1 gene., Methods: DNA samples were available from 22 individuals of this family, including 6 affected males and 6 obligate carriers. The nine exons of the OA1 gene were amplified and further analyzed by SSCP and sequencing., Results: A detailed clinical examination of the index patient and two female carriers showed the typical signs of ocular albinism. Visual evoked potential responses showed markedly asymmetrical responses from the two hemispheres in the affected person as well as in the carriers, as a result of misrouting and decussation of optic nerve fibers. Molecular genetic analysis demonstrated a previously undescribed 29-bp deletion at position 225-253 in exon 1 of the OA1 gene, which segregated in the family., Conclusion: Clinical examination combined with molecular genetic analysis enhances the potential for a precise diagnosis for persons at risk of x1OA and provide an accurate basis for genetic counseling.

Purpose: To measure changes in the relative spectral sensitivities of the dark adapted and light adapted ERG and thus to establish the possible contribution of rods to the 'blue cone' ERG elicited by flashes of blue light., Background: Short wavelength stimuli in the light-adapted eye evoke small rounded b-waves which have been considered to be S-cone responses. We have recorded such responses from tritanopes, which called the assumptions into question., Methods: Small ERGs were recorded to blue and green flashes. The stimulus was a Ganzfeld which employed light emitting diodes. ERGs were obtained in both the dark-adapted eye and after light adaptation to intense orange light (peak wavelength 610 nm). The change in sensitivity with light adaptation and the relative spectral sensitivity was determined from the voltage/log light intensity functions, using a 10 microV criterion., Results: (1) peak times and changes in sensitivity did not help distinguish light-adapted rod from possible S-cone responses; (2) analysis of the change in the ratio of blue:green sensitivity from darkness to 4.4 log Td. 610 nm background suggests that in seven normal subjects, 90% or more of the ERG evoked by 440 nm flashes is generated by S-cones; (3) three tritanopes have insignificantly reduced S-cone responses., Conclusions: (1) clinical techniques used to isolate S-cone ERGs are appropriate; (2) there are at least two types of tritanope and in those we investigated, functional S-cones are probably displaced into the retinal periphery.

A significant difference in the response density of the MF-ERG response has been suggested for every 2 diopter change of refraction. The influence of refractive blur on the MF-ERG was studied in 8 healthy volunteers using either the VERISTM system (Group A: n=5) or Retiscan(TM) (Group B: n=3). For each eye recordings were obtained with a corrective lens of -3 dpt, 0 dpt, +3 dpt and +6 dpt placed in front of the contact lens electrode. The viewing distance was adjusted to compensate for the induced changes in the retinal image size. When the changes in retinal image size due to the refractive lens were compensated for, no influence due to refraction was observed in either latencies or amplitudes of (KI (P > 0.05). This held true for the central response average (four degrees) as well as for the outer 6-25 degrees. In KII.1 only the peripheral amplitudes of Group B showed an influence due to refraction (P < or = 0.05). This may be due to adaptation as the recordings of group B were obtained in succession. As expected, significant differences were observed when the recordings obtained with the different systems were compared (P < or = 0.05).

319 patients with a solar retinopathy were seen in an eye clinic in Nepal within 20 months. All patients had either a positive history of sun-gazing or typical circumscribed scars in the foveal area. In more than 80% of the patients the visual acuity was 6/12 or better and did not deteriorate over time. 126 (40%) patients had a history of gazing at the sun during an eclipse, 33 (10%) were sun worshipers and 4 (1%) were in both categories. Three years later 29 patients were re-examined in a follow-up study. Only 16 had had visual disturbances directly after they had gazed into the sun. No colour vision defects were seen in any of the 44 affected eyes, when tested with Panel D 15, while four patients (6 eyes) had some uncertainty with the tritan plates of the Ishihara test charts. Metamorphopsia were recorded in 11 eyes. Five German patients with solar retinopathy were examined in more detail. Colour contrast sensitivity (CCS) was tested for the central and the peripheral visual field. CCS for tritan axis was raised in all patients for the central visual field, while it was normal for the peripheral visual field.

Purpose: Color vision deficits in patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV) disease were reported, and a retinal pathogenic mechanism was proposed. The purpose of this study was to evaluate the association of color vision deficits with HIV-related retinal microangiopathy., Methods: A computer graphics system was used to measure protan, deutan, and tritan color contrast sensitivity (CCS) thresholds in 60 HIV-infected patients. Retinal microangiopathy was measured by counting the number of cotton-wool spots, and conjunctival blood-flow sludging was determined. Additional predictors were CD4+ count, age, time on aerosolized pentamidine, time on zidovudine, and Walter Reed staging. The relative influence of each predictor was calculated by stepwise multiple regression analysis (inclusion criterion; incremental P value = < 0.05) using data for the right eyes (RE). The results were validated by using data for the left eyes (LE) and both eyes (BE)., Results: The only included predictors in multiple regression analyses for the RE were number of cotton-wool spots (tritan: R = .70; deutan: R = .46; and protan: R = .58; P < .0001 for all axes) and age (tritan: increment of R [Ri] = .05, P = .002; deutan: Ri = .10, P = .004; and protan: Ri = .05, P = .002). The predictors time on zidovudine (Ri = .05, P = .002) and Walter Reed staging (Ri = .03, P = .01) were additionally included in multiple regression analysis for tritan LE. The results for deutan LE were comparable to those for the RE. In the analysis for protan LE, the only included predictor was number of cotton-wool spots. In the analyses for BE, no further predictors were included. The predictors Walter Reed staging and CD4+ count showed a significant association with all three criteria in univariate analysis. Additionally, tritan CCS was significantly associated with conjunctival blood-flow sludging., Conclusion: CCS deficits in patients with HIV disease are primarily associated with the number of cotton-wool spots. Results of this study are in accordance with the hypothesis that CCS deficits are in a relevant part caused by neuroretinal damage secondary to HIV-related microangiopathy.

Color vision tests were performed on 211 German ophthalmologists during their annual meeting at Essen. The subjects also answered detailed questionnaires about their use of lasers and operating microscopes, and their ocular and general health. It was found that 33% of doctors who use lasers or operating microscopes have decreased color discrimination for colors in a tritan color-confusion axis (greater than 2 standard deviations above normal). There is a relationship between number of patients treated and the degree of threshold elevation. Thirty hours of using the operating microscope produces an increase in tritan threshold equivalent to one panretinal photocoagulation.

Macular phototoxicity is known to occur with laser use, and there is evidence that the wavelength of the light used influences this effect. In this study, a computer based colour contrast sensitivity test was used to assess the immediate macular effects of photocoagulation of peripheral flat retinal holes in otherwise normal retinas, using blue-green (488 and 514 nm), yellow (577 nm), orange (595 nm) or red (647 nm) laser light. The laser aiming beam was not allowed to traverse the macula at any stage during treatment. No protan or deutan axis threshold changes were noted in the 17 patients tested irrespective of the laser wavelength used. Tritan axis sensitivity was significantly reduced one hour after treatment with the blue-green laser, but no tritan axis change was found after treatment with longer wavelength lasers. The effect was no longer present the day after treatment in the subjects tested. The results show that even peripheral retinal treatment with blue-green laser can cause acute macular phototoxicity.

A total of 20 patients with unilateral acute optic neuritis were studied. Each patient had experienced the recent onset of a decrease in visual acuity, a relative afferent pupillary defect, a relative or absolute central scotoma and a colour-vision defect. The pattern-reversal electroretinogram (PERG) of each patient was analysed with regard to the amplitude of the positive and negative components. During the acute stage the amplitude of the positive component was reduced in all patients and that of the negative, in 18 of 20 cases. Parallel to clinical recovery, a steady increase was observed in the amplitude of the positive component to normal values; no statistical differences between affected and fellow eyes was found. In contrast, the amplitude of the negative component remained significantly reduced after clinical recovery.

Color contrast sensitivity was measured in laser operators before and after laser use. After argon blue-green laser treatment sessions, sensitivity was reduced for colors lying along a tritan color-confusion line for several hours. This acute effect is due to specular "flash-backs" from the aiming beam off the surface of the contact lens. It is caused only by argon 488-nm light, when the aiming beam intensity is high. In addition, a correlation has been demonstrated between the number of years of laser experience and a chronic reduction in tritan color contrast sensitivity. It is suggested that repeated acute changes caused by the argon lasers may cause cumulative effects and produce a chronic threshold elevation. A simple method of eliminating the acute effect is documented.

A survey was undertaken of a family known to have Sorsby's fundus dystrophy. Fifty members were reviewed, and 14 were found to be affected. Many of Sorsby's original conclusions were confirmed, including the pattern of inheritance and age of visual loss. Yellow material was present at the level of Bruch's membrane early in the course of the disease. However, the earliest phenotypic marker was delayed filling of the choriocapillaris. Abnormalities of choroidal perfusion became more profound and extended centrifugally with time. The loss of central vision was commonly due to atrophy of the outer retina and choroid. Subretinal neovascularization was a rare occurrence. The homology between this dystrophy and age-related macular disease underlines the importance of the clinical findings in this family.

Physiological experiments and the exploitation of clinical conditions have provided compelling evidence that retinal ganglion cells and other inner retinal structures generate the pattern ERG (PERG). As an increasing number of clinical reports have been published some contradictory findings have been reported. These may be ascribed to variation in recording and measuring techniques. The PERG consists of two major portions, the early positive and the following negative component which can be investigated separately if the stimulus conditions allow isolated (or "transient") responses to be recorded. Care has to be taken in positioning the reference electrode, maintaining accurate refraction, and the influence of pupil size must be considered. Furthermore the PERG is contaminated by a luminance component which may be generated in the outer retina. The size of this increases with low spatial frequency (large check-sizes) and high mean luminance. The PERG permits the examination of an additional level of the retina and helps the understanding of pathophysiology of various eye diseases, and is of clinical importance in routine diagnosis and assessment. In glaucoma the PERG amplitude is often reduced before it is possible to detect a scotoma and it is therefore an important prognostic indicator in patients with ocular hypertension. In diabetic retinopathy, retinal ischaemia sufficient to lead to the pre-proliferative state can be demonstrated. The PERG also has a major clinical role in examining localised retinal pathology. If combined with VECP recording, it greatly extends the interpretations possible, since not only can damage to the optic nerve be detected by both tests, but the normal PERG in the presence of an abnormal PVECP implies that the losses are confined to the central pathway.