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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 [...]

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.

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.

A new method of multifocal electroretinography making use of scanning laser ophthalmoscope with a wavelength of 630 nm (SLO-m-ERG), evoking short spatial visual stimuli on the retina, is proposed. Algorithm of presenting the visual stimuli and analysis of distribution of local electroretinograms on the surface of the retina is based on short m-sequences. Mathematical cross correlation analysis shows a three-dimensional distribution of bioelectrical activity of the retina in the central visual field. In normal subjects the cone bioelectrical activity is the maximum in the macular area (corresponding to the density of cone distribution) and absent in the blind spot. The method detects the slightest pathological changes in the retina under control of the site of stimulation and ophthalmoscopic picture of the fundus oculi. The site of the pathological process correlates with the topography of changes in bioelectrical activity of the examined retinal area in diseases of the macular area and pigmented retinitis detectable by ophthalmoscopy.

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.

Background: It is difficult to quantify thresholds in most colour vision tests, and this is especially the case for tritan hues, where a strong age-related increase of threshold has been reported. With the development of computer-graphic methods it is possible to remove brightness clues caused by lens absorption. This study attempts to give normative values for colour contrast thresholds and assess the age related changes therein., Patients and Methods: 115 patients aged between 6 & 71 years were tested for central and peripheral colour contrast sensitivity. No patient had any systemic or eye disease. As a preliminary, heterochromatic flicker balance between the luminosities of the R and G and B and G phosphors was established, so that all colours subsequently generated were isoluminant for the person tested. Then, using a modified binary search technique, colour contrast thresholds were established using both 2 degree optotypes, for central vision, and a ring, 12.5 degrees in radius for peripheral vision. In the latter case, the observer had to name the position of the missing quadrant in the ring. Stimuli were presented for 200 msec at 1 Hz. Colours were modulated on protan, deutan or tritan colour axis., Results: No correlation between age and central colour vision thresholds was observed. By contrast a significant but only minor increase of peripheral colour vision threshold was observed for the peripheral protan and tritan axis., Discussion: The present system removes luminance clues from colour vision tests and permits both central and peripheral retina to be tested. The results are simple in that the influence of age can be neglected. The variability of threshold results is small, and it is easy to detect the relatively large changes associated with disease. Since high-quality monitors are standardised and calibrated, providing the stimulus parameters described are adhered to, the results given here for upper limits of normal may be used for other similar systems.

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.

In 34 asymptomatic patients from three families at 50% risk of developing Sorsby's fundus dystrophy, colour contrast sensitivity was measured. In 16 the thresholds--mainly of the tritan axis--were raised above the normal values. It is concluded that testing of colour vision is useful in detecting the abnormal genotype. Raised colour contrast sensitivity was not observed before the first fundus or fluorescein angiographic changes in two of the families, while the colour defect occurred in the absence of ophthalmoscopic abnormality in the third family. Therefore, our results support the clinical suggestion that Sorsby's fundus dystrophy is more than one disease.

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.

We examined 44 HIV-positive patients in different disease stages with electroretinogram (ERG), pattern-electroretinogram (PERG), and visually evoked cortical potentials (VECP). Sixty-eight of the 88 eyes examined had a normal fundus and full central vision. Twelve eyes showed cotton-wool ecudates and 8 eyes CMV retinitis. Fifty-four eyes with normal fundus were examined by ERG. Of these 28 (52%) showed marked reduction of the amplitude. In the PERG, 20 eyes out of 50 examined (40%) showed an amplitude reduction. In the VECP, 12 out of 65 eyes (19%) had a reduced amplitude. In the ERG, 7 of 11 eyes (64%) with cotton-wool exudates showed marked pathological findings, as opposed to 4 of 10 cases (40%) in the PERG and 3 of 12 (12%) in the VECP. Seventy-five percent of the eyes with CMV retinitis (6 of 8 cases) showed pathological findings in the ERG and VECP and 100% (all 7 cases examined) in the PERG. These electrophysiological findings suggest that there are diffuse disorders in the retina of HIV-positive patients. It is possible that these findings are based on direct infection of the retina with HIV, or that they represent a vascular disorder, subclinical infection or are related to side effects of the drugs used for the HIV infection.