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This study aimed to systematically review and summarize gene therapy treatment for monogenic retinal and optic nerve diseases.This review was prospectively registered (CRD42021229812). A comprehensive literature search was performed in Ovid MEDLINE, Ovid Embase, Cochrane Central, and clinical trial registries (February 2021). Clinical studies describing DNA-based gene therapy treatments for monogenic posterior ocular diseases were eligible for inclusion. Risk of bias evaluation was performed. Data synthesis was undertaken applying Synthesis Without Meta-analysis guidelines.This study identified 47 full-text publications, 50 conference abstracts, and 54 clinical trial registry entries describing DNA-based ocular gene therapy treatments for 16 different genetic variants. Study summaries and visual representations of safety and efficacy outcomes are presented for 20 unique full-text publications in RPE65-mediated retinal dystrophies, choroideremia, Leber hereditary optic neuropathy, rod-cone dystrophy, achromatopsia, and X-linked retinoschisis. The most common adverse events were related to lid/ocular surface/cornea abnormalities in subretinal gene therapy trials and anterior uveitis in intravitreal gene therapy trials.There is a high degree of variability in ocular monogenic gene therapy trials with respect to study design, statistical methodology, and reporting of safety and efficacy outcomes. This review improves the accessibility and transparency in interpreting gene therapy trials to date.

To characterize red-green and tritan color discrimination in eyes with macular telangiectasia Type II (MacTel).Color discrimination was assessed by metameric matching methods using an Oculus MR Anomaloscope. Red-green color discrimination was assessed using the Rayleigh equation, and tritan color discrimination was assessed using the Moreland equation. Results were expressed as anomalquotient (AQ) and tritanomalquotient (TAQ) units, respectively.Seventeen eyes with MacTel were compared with 16 control eyes with normal vision. Twelve eyes with MacTel demonstrated abnormal color matches; except for two eyes with red-shifted Rayleigh matches, the primary abnormality evident was reduced color discrimination. On average, Rayleigh matching ranges were significantly widened in MacTel (0.518 ± 0.066 AQ units) compared with normal (0.14 ± 0.03 AQ units; P0.0001). Similarly, Moreland matching ranges were significantly wider (0.794 ± 0.109 TAQ units) than normal control subjects (0.204 ± 0.070 TAQ units; P0.0001). Losses in color discrimination did not correlate significantly with the best-corrected visual acuity, although Moreland matching ranges were significantly correlated to Rayleigh matching ranges.MacTel results in a combined acquired red-green and tritan color vision deficiency. A minority of eyes demonstrated red-shifted Rayleigh matches, consistent with decreases in cone photopigment optical density.

In anomalous trichromacy, the color signals available from comparing the activities of the two classes of cone sensitive in the medium and long wavelength parts of the spectrum are much reduced from those available in normal trichromacy, and color discrimination thresholds along the red-green axis are correspondingly elevated. Yet there is evidence that suprathreshold color perception is relatively preserved; this has led to the suggestion that anomalous trichromats post-receptorally amplify their impoverished red-green signals. To test this idea, we measured chromatic discrimination from white and from saturated red and green pedestals. If there is no post-receptoral compensation, the anomalous trichromat's loss of chromatic contrast will apply equally to the pedestal and to the test color. Coupled with a compressively nonlinear neural representation of saturation, this means that a given pedestal contrast will cause a smaller than normal modulation of discrimination sensitivity. We examined cases where chromatic pedestals impair the color discrimination of normal trichromatic observers. As predicted, anomalous observers experienced less impairment than normal trichromats, though they remained less sensitive than normal trichromats. Although the effectiveness of chromatic pedestals in impairing color discrimination was less for anomalous than for normal trichromats, the chromatic pedestals were more effective for anomalous observers than would be expected if the anomalous post-receptoral visual system were the same as in normal trichromacy; the hypothesis of zero compensation can be rejected. This might suggest that the effective contrast of the pedestal is post-receptorally amplified. But on closer analysis, the results do not support candidate simple models involving post-receptoral compensation either.

Background Cone-rod dystrophy (CORD) is a group of inherited retinal dystrophies, characterized by decreased visual acuity, color vision defects, photophobia, and decreased sensitivity in the central visual field. Our study has identified a novel pathogenic variant associated with X-linked cone-rod dystrophy (XLCORD) in a Chinese family. Methods All six family members, including the proband, affected siblings, cousins and female carriers, have underwent thorough ophthalmic examinations. The whole exome sequencing was performed for the proband, followed by Sanger sequencing for spilt-sample validation. A mammalian expression vector (AAV-MCS) with mutated retinitis pigmentosa GTPase regulator (RPGR) sequence was expressed in HEK293 T cells. The mutated protein was verified by Western blotting and immunohistochemistry. Results A novel mutation in the RPGR gene (c.2383G > T, p.E795X) is identified to be responsible for CORD pathogenesis. Conclusions Our findings have expanded the spectrum of CORD-associated mutations in RPGR gene and serve as a basis for genetic diagnosis for X-linked CORD.

Non-organic vision loss can manifest in various ways, most commonly in the form of reduced vision and visual field defects. Colour vision disorders in the context of a conversion disorder have only rarely been reported.This review presents the case of a 9-year-old boy with a colour vision disorder as the isolated symptom of a conversion disorder. The challenging in this case was an additional somatic comorbidity - a congenital red-green deficiency. Consequently it was difficult to make a diagnosis and to convince the parents.It is important to rule out organic causes and establish the diagnosis of a conversion disorder. In these cases, multidisciplinary treatment is crucial for a successful outcome. The diagnosis may be especially challenging when the patients have both somatic and psychogenic complaints.Nichtorganische Sehstörungen können sich verschiedenartig manifestieren. Die häufigsten Symptome sind Visusminderungen und Gesichtsfelddefekte. Farbsinnstörungen im Rahmen einer Konversionsstörung sind selten.Dieser Artikel behandelt den Fall eines 9-jährigen Jungen mit einer Farbsinnstörung als alleiniges Symptom einer Konversionsstörung. Die diagnostische Herausforderung in diesem Fall war eine zusätzlich vorliegende somatische Komorbidität – eine kongenitale Rot-Grün-Schwäche, die eine Diagnosestellung und deren Akzeptanz erschwerte.Zunächst sollten umfassende zielorientierte Tests zum Ausschluss einer organischen Ursache erfolgen. Bei Vorliegen einer Konversionsstörung ist eine interdisziplinäre Zusammenarbeit von Ophthalmologen und Psychiatern/Psychologen wichtig. Gerade das zeitgleiche Vorliegen von somatischen und psychogenen Beschwerden kann diagnostisch herausfordernd sein.

Background: Bornholm eye disease (BED) is a rare X-linked cone dysfunction disorder with high myopia, amblyopia, and color vision defects.Materials and methods: Visual and ocular outcomes in a family where two of five siblings had molecularly confirmed BED are reported. Ophthalmological assessments included best-corrected visual acuity (BCVA), color vision test, and optical coherence tomography (OCT). Medical records, electroretinography (ERG), and genetic analyses were re-evaluated.Results: Two male siblings had confirmed BED with myopia and protanopia. The younger brother had high myopia, subnormal BCVA, and ocular fundi that showed tilted discs, crescent shaped peripapillary atrophy, and visible choroidal vessels. OCT confirmed retinal and choroidal atrophy. The older brother was lightly myopic with normal/subnormal BCVA and subtle findings in the fundi. Both brothers had abnormal ERG recordings with a decreased cone response. They also had a structurally intact OPN1LW/OPN1MW gene cluster. The OPN1LW gene was shown to carry a deleterious variant combination in exon 3 known to result in mis-splicing of opsin mRNA and acknowledged as LIAVA amino acid delineation (Leu153-Ile171-Ala174-Val178-Ala180), while the OPN1MW gene exon 3 showed a non-pathogenic variant combination (MVVVA). Another normal-sighted brother carried another wildtype variant combination (LVAIS) in exon 3 of the OPN1LW gene.Conclusions: The two affected brothers demonstrated a large variability in their phenotypes even though the genotypes were identical. They presented a disease-associated haplotype in exon 3 of OPN1LW that has been described as the molecular cause of BED.

Anomalous trichromacy is a form of color vision deficiency characterized by the presence of three cone types, but with shifted spectral sensitivities for L or M cones, causing a red-green color deficiency. However, long-term adaptation to this impoverished opponent input may allow for a more normal color experience at the suprathreshold level (“compensation”). Recent experimental evidence points to the presence of compensation in some tasks. The current study used threshold detection, suprathreshold contrast matching, and a reaction-time task to compare contrast coding in normal and anomalous observers along the cardinal cone-opponent axes. Compared to color normals, anomals required more L-M contrast, but not S contrast, to detect stimuli and to match an achromatic reference stimulus. Reaction times were measured for several contrast levels along the two cone-opponent axes. Anomals had higher overall reaction times, but their reaction-time versus contrast functions could be matched to those of controls simply by scaling contrast by the detection thresholds. Anomalous participants were impaired relative to controls for L-M stimuli in all three tasks. However, the contrast losses were three times greater for thresholds and reaction times than for suprathreshold matches. These data provide evidence for compensation in anomalous trichromats, but highlight the role that the experimental task plays in revealing it.

Purpose To investigate the sensitivity of the color vision test by Arden in patients with dysthyroid optic neuropathy (DON) to improve diagnosis. Methods In this observational, retrospective study, we included the medical records of 92 eyes (48 patients) with diagnosis of DON between 2008 and 2019 in order to evaluate the full spectrum of findings from the color vision test by Arden, and to determine potential importance of this test. Thirty-five patients were female, and 13 patients were male. The mean age was 58.0 years (range: 34–79) at the time of the DON diagnosis. Results Forty-one eyes displayed relatively good BCVA with ≤ 0.2 LogMAR. We found a protan value exceeding the threshold of ≥ 8% in 57 eyes (30 patients) at the time of the diagnosis. The sensitivity of protan was 61.9% (95% CI 51.2–71.8%), while that of tritan was a striking 98.9% (95% CI 94.1–99.9%). We discovered one pathological sign, tritan deficiency (based on a threshold of ≥ 8%) consistently in all eyes but one at the time of the diagnosis, regardless of the visual field defects or any changes in best-corrected visual acuity (BCVA). Conclusion We found blue-yellow (tritan) deficiency, to be a sensitive and reliable indicator of dysthyroid optic neuropathy. We conclude that, in cases with suspected DON, a color vision test that can detect tritan deficiency is an essential tool for the adequate assessment, diagnosis, and treatment of DON.

AimsTo determine long-term safety and efficacy outcomes of a subretinal gene therapy for CNGA3-associated achromatopsia. We present data from an open-label, nonrandomised controlled trial (NCT02610582).MethodsDetails of the study design have been previously described. Briefly, nine patients were treated in three escalating dose groups with subretinal AAV8.CNGA3 gene therapy between November 2015 and October 2016. After the first year, patients were seen on a yearly basis. Safety assessment constituted the primary endpoint. On a secondary level, multiple functional tests were carried out to determine efficacy of the therapy.ResultsNo adverse or serious adverse events deemed related to the study drug occurred after year 1. Safety of the therapy, as the primary endpoint of this trial, can, therefore, be confirmed. The functional benefits that were noted in the treated eye at year 1 were persistent throughout the following visits at years 2 and 3. While functional improvement in the treated eye reached statistical significance for some secondary endpoints, for most endpoints, this was not the case when the treated eye was compared with the untreated fellow eye.ConclusionThe results demonstrate a very good safety profile of the therapy even at the highest dose administered. The small sample size limits the statistical power of efficacy analyses. However, trial results inform on the most promising design and endpoints for future clinical trials. Such trials have to determine whether treatment of younger patients results in greater functional gains by avoiding amblyopia as a potential limiting factor.

Color vision deficiencies are a group of vision disorders, characterized by abnormal color discrimination. They include red-green color blindness, yellow-blue color blindness and achromatopsia, among others. The deficiencies are caused by mutations in the genes coding for various components of retinal cones. Gene therapy is rising as a promising therapeutic modality. The purpose of this review article is to explore the available literature on gene therapy in the different forms of color vision deficiencies. A thorough literature review was performed on PubMed using the keywords: color vision deficiencies, gene therapy, achromatopsia and the various genes responsible for this condition (OPN1LW, OPN1MW, ATF6, CNGA3, CNGB3, GNAT2, PDE6H, and PDE6C). Various adenovirus vectors have been deployed to test the efficacy of gene therapy for achromatopsia in animals and humans. Gene therapy trials in humans and animals targeting mutations in CNGA3 have been performed, demonstrating an improvement in electroretinogram (ERG)-investigated cone cell functionality. Similar outcomes have been reported for experimental studies on other genes (CNGB3, GNAT2, M- and L-opsin). It has also been reported that delivering the genes via intravitreal rather than subretinal injections could be safer. There are currently 3 ongoing human clinical trials for the treatment of achromatopsia due to mutations in CNGB3 and CNGA3. Experimental studies and clinical trials generally showed improvement in ERG-investigated cone cell functionality and visually elicited behavior. Gene therapy is a promising novel therapeutic modality in color vision deficiencies.

To evaluate the changes in functional vision in patients with resolved endophthalmitis. This was a cross-sectional study. The study included 20 patients with resolved endophthalmitis and best-corrected visual acuity of 20/100 or better. Visual acuity (VA), contrast threshold (CT), red/green (RG) and yellow/blue (YB) colour vision and 15 Hz flicker modulation threshold (FMT) were assessed using standard psychophysical techniques. The median age was 54 years. The median visual acuity was 0.27 (~ 20/40—Snellen Equivalent) ((interquartile range [IQR]), 0.30) logMAR). The median log contrast threshold (CT) was − 1.13 (IQR, 0.36) log units (normative value for age-matched CT: − 1.61 log units). The median red/green (RG) and yellow/blue (YB) thresholds were 11.52 (IQR, 26.19) and 9.45 (IQR, 16.20) CAD units respectively, which were at least 5 times higher than age-matched normative RG and YB thresholds. The median central cone- mediated FMT was 17.64% (IQR, 23.40%), which was much higher compared to age-matched FMT (5.48% [IQR, 3.47]). Linear regression revealed significant relationship between contrast thresholds and foveal thickness (y = 0.001x−1.47, R2 = 0.20, p = 0.048). Though endophthalmitis may resolve with a good visual acuity, deficits in visual functions like chromatic discrimination, cone-mediated flicker and contrast sensitivity persist.

Diagnosing colour vision deficiency is vital, owing to its impact on the choice of career and activities of daily living. Conventional screening methods require frequent replacement due to soiling of the materials, and hence are expensive and not feasible for large-scale community screening. This study aims to construct and validate a new screening tool, Dalton's pseudo-isochromatic plates (PIP), addressing the disadvantages of the conventional methods.The two phases of the study included the construction and validation of the Dalton's PIP. Construction involved utilising specific wavelengths based on spectral tuning, selection of numerals as targets for the chart and identification of a material with durability and resistance to wear and tear. Validation of the chart was done against the 38-plate edition of Ishihara's PIP by two masked examiners for 1,019 school children aged between 11-17 years (mean ± SD: 14 ± 2 years) as part of a school eye-health program.The sensitivity and the specificity of the Dalton's PIP was found to be 94.12 per cent (95% CI 71.31-99.85) and 99.60 per cent (95% CI 98.98-99.89) respectively and the positive and negative predictive values were 80 per cent and 99.90 per cent respectively. Dalton's PIP when used with a failure criterion of less than three plates correct in two screening sets had the maximum sensitivity and specificity and the area under the curve was 0.96 (95% CI 0.90-0.99, p 0.05).The newly constructed Dalton's PIP is found to be a valid screening tool to detect congenital colour vision deficiency and is comparable to the Ishihara PIP. This screening tool with its shorter screening time, cost and longer durability would effectively serve in large-scale vision screening programs.

Traditional color vision tests depend on subjective judgments and are not suitable for infant children and subjects with cognitive dysfunction. We aimed to explore an objective and quantitative color vision testing method based on sweep steady-state visual evoked potentials (sweep SSVEPs) and compare the results with subjective Farnsworth–Munsell (FM) 100-hue test results. A red-green SSVEP pattern reversal checkboard paradigm at different luminance ratios was used to induce visual evoked potentials (VEPs) from 15 color vision deficiencies (CVDs) and 11 normal color vision subjects. After electroencephalography signals were processed by canonical correlation analysis, an equiluminance turning curve corresponding to the activation of the L-cones and M-cones at different levels of color vision was established. Then, we obtained different equiluminance T and proposed the SSVEP color vision severity index (ICVD) to quantify color vision function and the severity of CVDs. In addition, the FM 100-hue test was used to obtain subjective data for the diagnosis of color vision. The value of ICVD can be an indicator of the level of color vision. Both the total error scores (TES) and confusion index (C-index) of the FM 100-hue test were significantly correlated with ICVD values (P

Many studies have examined how color and luminance information are processed in the visual system. It has been observed that chromatic noise masked luminance discrimination in trichromats and that luminance thresholds increased as a function of noise saturation. Here, we aimed to compare chromatic noise inhibition on the luminance thresholds of trichromats and subjects with severe deutan or protan losses. Twenty-two age-matched subjects were evaluated, 12 trichromats and 10 with congenital color vision impairment: 5 protanopes/protanomalous, and 5 deuteranopes/deuteranomalous. We used a mosaic of circles containing chromatic noise consisting of 8 chromaticities around protan, deutan, and tritan confusion lines. A subset of the circles differed in the remaining circles by the luminance arising from a C-shaped central target. All the participants were tested in 4 chromatic noise saturation conditions (0.04, 0.02, 0.01, 0.005 u′v′ units) and 1 condition without chromatic noise. We observed that trichromats had an increasing luminance threshold as a function of chromatic noise saturation under all chromatic noise conditions. The subjects with color vision deficiencies displayed no changes in the luminance threshold across the different chromatic noise saturations when the noise was composed of chromaticities close to their color confusion lines (protan and deutan chromatic noise). However, for tritan chromatic noise, they were found to have similar results to the trichromats. The use of chromatic noise masking on luminance threshold estimates could help to simultaneously examine the processing of luminance and color information. A comparison between luminance contrast discrimination obtained from no chromatic and high-saturated chromatic noise conditions could be initially undertaken in this double-duty test.

BACKGROUND To evaluate the effects of the ChromaGen contact lens (CCL) on best-corrected visual acuity, contrast sensitivity and pseudoisochromatic test plate performance in patients with congenital colour vision deficiency (CVD). METHODS CCLs were inserted into 50 eyes of 25 patients with congenital red-green CVD. The patients were tested with the Ishihara and Hardy-Rand-Rittler test plates before and after the insertion of Magenta 2, Magenta 3, and Violet 3 CCLs. The patients' mean numbers of recognised symbols were calculated and the most appropriate CCL was determined for each eye. The best-corrected visual acuity for both far and near vision and contrast sensitivity were evaluated before and after the insertion of the appropriate CCLs, and the results were compared. RESULTS The mean age of the patients was 26.56 ± 10.30 years. While all CCLs increased the mean numbers of recognised symbols on the Ishihara (p

Purpose To evaluate structural grading and quantitative segmentation of foveal hypoplasia using handheld OCT, versus preferential looking (PL), as predictors of future vision in preverbal children with infantile nystagmus. Design Longitudinal cohort study. Participants Forty-two patients with infantile nystagmus (19 with albinism, 17 with idiopathic infantile nystagmus, and 6 with achromatopsia) were examined. Methods Spectral-domain handheld OCT was performed in preverbal children up to 36 months of age. Foveal tomograms were graded using our 6-point grading system for foveal hypoplasia and were segmented for quantitative analysis: photoreceptor length, outer segment (OS) length, and foveal developmental index (FDI; a ratio of inner layers versus total foveal thickness). Patients were followed up until they could perform chart visual acuity (VA) testing. Data were analyzed using linear mixed regression models. Visual acuity predicted by foveal grading was compared with prediction by PL, the current gold standard for visual assessment in infants and young children. Main Outcome Measures Grade of foveal hypoplasia, quantitative parameters (photoreceptor length, OS length, FDI), and PL VA were obtained in preverbal children for comparison with future chart VA outcomes. Results We imaged 81 eyes from 42 patients with infantile nystagmus of mean age 19.8 months (range, 0.9–33.4 months; standard deviation [SD], 9.4 months) at the first handheld OCT scan. Mean follow-up was 44.1 months (range, 18.4–63.2 months; SD, 12.0 months). Structural grading was the strongest predictor of future VA (grading: r = 0.80, F = 67.49, P < 0.0001) compared with quantitative measures (FDI: r = 0.74, F = 28.81, P < 0.001; OS length: r = 0.65; F = 7.94, P < 0.008; photoreceptor length: r = 0.65; F = 7.94, P < 0.008). Preferential looking was inferior to VA prediction by foveal grading (PL: r = 0.42, F = 3.12, P < 0.03). Conclusions Handheld OCT can predict future VA in infantile nystagmus. Structural grading is a better predictor of future VA than quantitative segmentation and PL testing. Predicting future vision may avert parental anxiety and may optimize childhood development.

Objective The purpose of this study was to determine if there is an association between Perceptual Ability Test (PAT) results and color vision deficiency (CVD). Methods Three consecutive classes of first-year dental students (n = 291) voluntarily participated in the study. The Farnsworth-Munsell 100 Hue Color Vision test (FM-100) was administered to students beneath a Macbeth Judge II viewing booth that provided ideal lighting conditions to ascertain CVD. Results of FM-100 test were recorded as total error scores (TES). Color acuity was scored as superior (TES 0-16), average (TES 20-100), or poor (TES > 100). Additional information of age, sex, ethnicity, and time to complete the FM-100 was obtained. Multiple linear regression was used to determine the association between PAT and CVD while adjusting for age, sex, ethnicity, and time to complete the FM-100 test. Results TES ranged from 0-244. There were 132 students with superior color acuity, 161 with average, and eight with poor acuity. Females performed better than males on the FM-100 test. Time to complete the FM-100 test ranged from 3:40 minutes to 25:12 minutes. There was a strong relationship between PAT scores and CVD (P = 0.0003). A 1-unit increase in PAT scores was found to result in a 9% decrease in TES; indicating that students with higher PAT scores are less likely to have CVD. Conclusion The PAT may be a preliminary screening instrument to identify students who may have CVD. The FM-100 test can then confirm the presence of CVD. Students with CVD may desire to improve dental shade matching skills through targeted training and education.

Charcot-Marie-Tooth (CMT) constitutes a group of heterogeneous hereditary motor and sensor neuropathies. Mutations in mitofusin-2 (MFN2) cause CMT type 2A by altering mitochondrial fusion and trafficking along with the axonal microtubule system. In literature patients presenting with CMT2A are reported as having a subacute onset of optic atrophy associated with central scotoma and color vision defects. We report on the clinical and genetic findings in a 40 years-old Caucasian woman presenting with CMT type 2A and MFN2 mutation (c.2258duplT/p.Leu753fs) who presented bilateral progressive optic atrophy with bilateral severe concentric narrowing of the visual field but normal visual acuity and color vision. This is the first report that describes such phenotypical manifestation of an MFN2 mutation suggesting that the molecular mechanisms underlying the mitofusin-2 function alteration at optic nerve need to be investigated further.

For patients with color vision defects, owing to the destruction of cone cells and loss of function, some color information is lost, hence changing the originally transmitted information by the image. The purpose of the traditional method of correction is to help patients distinguish between colors, but it does not take into account the problem of the saliency of the image. In this paper, we propose a saliency consistency-based image re-colorization for color blindness. We use image retrieval methods to select a large number of images and use co-saliency methods to detect salient areas of standard color images and color-blind simulated images. According to the detection results, an image with the same detection result was selected as the reference image. We grayscale the significantly changed image, recolor the grayscale image using the reference image, and the color scheme of the recolored image is similar to the reference image. The color matching scheme of the reference image makes the significance of the image basically unchanged in standard vision and color vision defects, thereby making the color blindness patient’s perception of the image close to standard vision. We invite green blind patients to evaluate CVD simulation images with different recoloring methods subjectively. In addition, we use different evaluation criteria to evaluate the experimental results objectively. In the subjective evaluation and objective evaluation, the method proposed in this paper has achieved good results, which validates the effectiveness of our method.

Visual impairment due to refractive errors and color vision deficiency (CVD) can affect the visual abilities of workers in workplace. Identifying the prevalence of common visual problems helps us to prevent and treat occupational ocular problems. This study was conducted on 2600 males referring from companies for a routine medical exam to Occupational Medicine Center. In all subjects, visual acuity and refraction were measured. Assessment of color vision was performed by Ishihara color test. In present study, right eyes of subjects were selected to statistical analysis. The mean spherical equivalent was –0.19 ± 1.39 diopter with a range of –11.00 to +10.00 diopter. Whereas 71% of persons were emmetropic, 20% and 9% of them were myopic and hypermetropic, respectively. From a total subjects, 164 of them had CVD with prevalence of color blindness of 6.3%. In comparison with normal subjects, CVD had no significant effect on refractive findings of our subjects (P > .05). Our data present the prevalence of refractive errors and color blindness among Iranian industry-workers. Compared with other studies, our subjects have a lower prevalence of refractive errors, and similar rate of prevalence of color blindness.

Background: Although in clinical practice an impairment of sensory perception is frequently reported by depressed patients no mention of these symptoms is made in DSM-5, ICD-10 or ICD-11. Previous studies on colour perception have largely relied on patient self-reports and few have studied colour discrimination.Methods: The ability to discriminate small colour differences was assessed in 30 patients currently experiencing a moderate to severe depressive episode (ICD-10: F32.1-2, F33.1-2 or F31.3-4) and 32 healthy controls using the colour buttons of the Farnsworth Munsell 100-Hue test. Data were analysed by standard tests for comparing two groups (t-test, Mann-Whitney U-test, Chi-square test) and by ordinal regression and generalised estimating equation models.Results: Depressed patients failed significantly earlier (i.e., at larger differences between adjacent buttons) to discriminate between colours. This finding was retained after adjustment for potential confounders. There was no significant association with age, gender or depression score.Conclusions: We found a reduction in the ability to discriminate colours in depressed patients. This finding underlines the importance of sensory deficits as part of the symptomatology of depression. Sensory impairments should be taken into account in clinical care of patients with depression and should be included in diagnostic manuals. Further studies in larger samples including intra-individual comparisons between the depressed and the remitted state of patients are needed.Key pointsIn clinical practice, an impairment of sensory perception is frequently reported by depressed patients.However, no mention of these symptoms is made in the commonly used diagnostic manuals.In this pilot study, depressed patients and controls differed significantly in terms of the ability to discriminate colours with patients performing worse than their healthy counterparts.Sensory impairments should be taken into account in clinical care of patients with depression and should be included in diagnostic manuals.

Images can be made more accessible by choosing hues, shapes and textures carefully. Images can be made more accessible by choosing hues, shapes and textures carefully.

The ability of the adult human brain to develop function following correction of congenital deafferentation is controversial. Specifically, cases of recovery from congenital visual deficits are rare. CNGA3-achromatopsia is a congenital hereditary disease caused by cone-photoreceptor dysfunction, leading to impaired acuity, photoaversion, and complete color blindness. Essentially, these patients have rod-driven vision only, seeing the world in blurry shades of gray. We use the uniqueness of this rare disease, in which the cone-photoreceptors and afferent fibers are preserved but do not function, as a model to study cortical visual plasticity. We had the opportunity to study two CNGA3-achromatopsia adults (one female) before and after ocular gene augmentation therapy. Alongside behavioral visual tests, we used novel fMRI-based measurements to assess participants' early visual population receptive-field sizes and color regions. Behaviorally, minor improvements were observed, including reduction in photoaversion, marginal improvement in acuity, and a new ability to detect red color. No improvement was observed in color arrangement tests. Cortically, pretreatment, patients' population-receptive field sizes of early visual areas were untypically large, but were decreased following treatment specifically in the treated eye. We suggest that this demonstrates cortical ability to encode new input, even at adulthood. On the other hand, no activation of color-specific cortical regions was demonstrated in these patients either before or up to 1 year post-treatment. The source of this deficiency might be attributed either to insufficient recovery of cone function at the retinal level or to challenges that the adult cortex faces when computing new cone-derived input to achieve color perception. SIGNIFICANCE STATEMENT The possibility that the adult human brain may regain or develop function following correction of congenital deafferentation has fired the imagination of scientists over the years. In the visual domain, cases of recovery from congenital deficits are rare. Gene therapy visual restoration for congenital CNGA3-achromatopsia, a disease caused by cone photoreceptor dysfunction, gave us the opportunity to examine cortical function, to the best of our knowledge for the first time, both before and after restorative treatment. While behaviorally only minor improvements were observed post-treatment, fMRI analysis, including size algorithms of population-receptive fields, revealed cortical changes, specifically receptive field size decrease in the treated eyes. This suggests that, at least to some degree, the adult cortex is able to encode new input.

Ethionamide is part of a group of drugs used in the treatment of drug resistant TB. With the advent of increasing drug resistance in pulmonary TB cases, use of Ethionamide, a second line anti tubercular drug is increasing. Vision changes are rare with ethionamide. Cyanopsia i.e., bluish tinted vision of surroundings with ethionamide is not known in literature. Here, we report a case of DRTB patient who developed cyanopsia soon after introducing ethionamide. Although reversible, ethionamide may sometimes need withdrawal because of significant distress caused to patient.

Background: Color vision tests are routinely performed and are mandatory in most part of the world. However, in Nepal and many other developing countries, color vision may often be overlooked. We evaluated a possible burden of color vision in a group of patients who were specifically evaluated for a color vision defects. This study evalutes the awareness of color vision defect among the patients evaluated and highlights the importance of the color vision evaluation. Methods: A sequential group of 73 people from August to September 2017 specifically evalu­ated for color vision defect for recruitment of government employment were evaluated. Ishi­harapseudo-isochromatic plates and Farnsworth-Munsell Dichotomous D-15 test were used for screening. Mean and Standard deviation were used for descriptive analysis of the data. Results: Fifty-seven were male and sixteen were female. The mean age was 23 years (SD ± 3.7). On evaluation of the color vision defect, 9 (12.3%) were found to have total color vision defect (achromatopsia), 3 (4%)-red-green defect and 1(1%) with blue red defect. None of the patients had undergone color vision test at eye hospital previously. There were 4 patients who were registered drivers who had color vision defect. Conclusions: Color vision is an important part of the vision. It should not be ignored.All of the patients evaluated were found to be unware of their condition. Early detection of color vision defects in individuals, if possible, at school level can help them to determine their careers and future endeavors at early stage.

To report a rare case of bilateral retinopathy and optic neuropathy in a patient of systemic sclerosis (SSc).Retrospective case report.A 30-year-old South Indian lady presented with bilateral pale disc oedema and telangiectatic disc vessels and bilateral drusen-like deposits (DLDs) in the macula. Fundus fluorescein angiography additionally revealed microaneurysmal dilatation and leakage from peripheral retinal vasculature and patchy choroidal ischemia. She had defective colour vision (OS) and a central scotoma with enlarged blind spot (OD) and centrocecal scotoma (OS). Systemic features and a strongly positive anticentromere antibody led to the diagnosis of limited cutaneous SSc with a score of 12 on the ACR/EULAR criteria.We describe a rare case of bilateral retinopathy with DLDs and bilateral optic neuropathy in a non-hypertensive patient who was not previously diagnosed as SSc. A prior association of DLDs have not been described in SSc (PubMed Search).

Objectives Congenital colour vision deficiency (CCVD) is an x-linked chromosome disorder that results from abnormalities in one or all three-cone type’s photoreceptors. Early assessment and diagnosis of CCVD is necessary to minimise the disability associated with the condition. Multistage sampling was used to determine the prevalence of CCVD among Black South African school children in Durban, South Africa. The examination included visual acuity measurements, ocular motility evaluation, retinoscopy, auto-refraction, and examination of the anterior segment, media and fundus. Colour vision testing was performed using Colour Vision Testing Made Easy colour plates (Home Vision Care, Gulf Breeze, FL). Results 1305 (704 boys and 601 girls) Black school children participated in the study. The overall prevalence of colour vision deficiency was 29 (2.2%), which was higher in boys (25, 4.2%) than girls (4, 0.6%), with prevalence of protanopia and deuteranopia found to be 10 (0.7%) and 19 (1.5%), respectively. The prevalence of protanopia and deuteranopia among males was nine (1.5%) and 16 (2.7%) respectively, which was significantly higher than the 1 (0.1%) protanopia and 3 (0.4%) deuteranopia in females (p

The present pilot study was undertaken to investigate the impaired acquired color vision on Calabrian male sample showing this parameter as a biological marker in type 2 diabetes. All patients and controls underwent three pseudo-isochromatic clinical test batteries: Ishihara test, Farnsworth test, and City University test. The results show a specific loss of short-wavelength (blue sensitivity) and typical tritan responses in diabetic patients. Generally, in later stages of the disease, the red-green mechanisms are involved. By the impaired color vision study in diabetic patients, we can confirm the impaired retina-brain cortex pathway. We believe that the above not invasive test analysis can support the other instrumental and imaging analysis to study the impaired retina-brain cortex pathway. Moreover, we think that the present clinical method can be useful in terms of preventive medicine.

Visual disorders like double vision, dry eyes, and visual field deficits are common but frequently missed in Parkinson's disease. Here, we aim to increase awareness for these visual disorders in Parkinson patients by discussing several common problems that can be easily diagnosed using comprehensive history taking and a basic neuro-ophthalmological examination. We offer practical guidance for the patient interview and physical exam that can facilitate a timelier recognition of visual disorders. Such recognition has immediate therapeutic relevance, because Parkinson patients are strongly dependent on an adequate vision, for example to optimally benefit from visual cueing strategies.

PURPOSE: To evaluate the use of the Cone Contrast Test (CCT) as a color vision screening tool in an Asian population of aircrew applicants and compare it against the Ishihara Psuedo Isochromatic Plates (PIP) - Edridge Lantern Test (ELT) screening pathway, assessing its impact on attrition with CCT cut-off scores of 55 and 75.METHODS: This is a retrospective review of 862 Republic of Singapore Airforce aircrew applicants tested with CCT and Ishihara PIP-ELT combination as screening. CCT repeatability was analyzed by comparing the subject's interocular (right vs. left eye) scores measured as the coefficient of repeatability (COR), with COR differing by ≥15 points considered to be outside normal limits.RESULTS: Of the applicants, 17 (1.97%) failed to achieve a CCT score of ≥55 (5 protan, 12 deutan), while 26 (3.02%) applicants failed to achieve a score ≥75 (5 protan, 21 deutan). Of the 17 applicants who obtained a CCT score of

Objective: To evaluate the influence of the extent of color-vision deficiency on visual shade-matching ability. Materials and methods: Six groups were investigated: the control group (N = 68), the protan medium deficiency (PMED) group (N = 5), the protan strong deficiency (PSTD) group (N = 5), the deutan mild deficiency (DMID) group (N = 5), the deutan medium deficiency (DMED) group (N = 5) and the deutan strong deficiency (DSTD) group (N = 8). The color vision of the participants was evaluated monocularly using the Hardy-Rand-Rittler (HRR) test and on an HMC Anomaloskop MR (Rayleigh test). The final exam on a Toothguide Training Box consisted of 15 lightness–chroma–hue tasks. The color difference (ΔE* ab) and the shade-matching score (ΣΔE* ab) were computed. The means and the standard deviations for the ΣΔE* ab were calculated. An independent t-test was used for statistical analyses of the data and a comparison of means (α = .05) for protan groups and a one-way analysis of variance (ANOVA) and a post-hoc Bonferroni test (α = .05) for deutan groups. Results: The PSTD group had a mean ΣΔE* ab of 63.38 ± 9.52, which means their elections were significantly worse in comparison to the PMED group (ΣΔE* ab = 47.62 ± 9.88, p = 0.033). The selections of the control group were significantly better in comparison to all groups with color-vision deficiency (control – PMED, p = 0.031; control – PSTD, p < 0.0001; control – DMED, p < 0.0001; control – DSTD, p < 0.0001), except in comparison with DMID group (p = 0.082). The comparisons between deutan groups were not significantly different (DMID – DMED, p = 0.352; DMID – DSTD, p = 0.323; DMED – DSTD, p = 1.000). Conclusion: Participants with strong protan color-vision deficiency are worse at shade matching than participants with medium protan color-vision deficiency.

Background: Congenital colour vision defects are x-linked inherited, non-progressive and untreatable disorders that describe poor colour discrimination. Objective: To determine the prevalence of congenital colour vision deficiency among students in Lagos, Nigeria. Methods: A school-based cross-sectional, cluster sample study was conducted to test the colour vision of 2326 primary and high school students. Inclusion criteria were Snellen VA 20/20 or better and absence of known ocular pathologies. Colour vision deficiency (CVD) was evaluated with the Richmond-HRR colour vision test plates. Results: There were 1014 (43.6%) males and 1312 (56.4%) females with a mean age of 13.40 ± 2.40 years (range = 7−22 years). The prevalence of CVD was 58 (2.5%), which was higher in males 49 (4.8%) than females 9 (0.7%). The prevalence of congenital CVD was significantly associated with males (p = 0.00), but not with females (p = 0.22). Of the 58 cases of CVD, 17 (0.7%) had protan deficiency, 38 (1.6%) had deutan deficiency and three (0.1%) were unclassified. Conclusion: The prevalence of congenital CVD among students in Lagos is comparable to findings in other parts of Nigeria but differs from other parts of the country. These results strengthen the need to establish school vision screening. Keywords: Colour vision deficiency, Richmond-HRR, prevalence, red-green defects, Nigeria.

PURPOSE: To assess the effect of type and severity of congenital color vision deficiency (CCVD) on depth perception. METHODS: Thirty-one male patients with a known diagnosis of CCVD were included in the study group and 31 age-matched healthy subjects in the control group. After standard ophthalmological examination including best corrected visual acuity (BCVA) testing with Snellen chart, slit-lamp examination, non-contact tonometry, and fundus examination, all patients underwent color perception testing with Hardy–Rand–Rittler (HRR) 4th edition pseudoisochromatic test plates and stereoacuity testing with Titmus stereo test plates. RESULTS: Of the 31 patients with CCVD, 7 were protanope and 24 were deuteranope. Mean stereoacuity was 46.77 ± 11.3, 105.7 ± 69.0, and 134.1 ± 115.2 in the control, protanope, and deuteranope groups, respectively. Stereoacuity was significantly better in the control group than in the protanope and deuteranope groups (p = 0.039, p

There is a need for a straightforward, accessible and accurate pediatric test for color vision deficiency (CVD). We present and evaluate ColourSpot, a self-administered, gamified and color calibrated tablet-based app, which diagnoses CVD from age 4. Children tap colored targets with saturations that are altered adaptively along the three dichromatic confusion lines. Two cohorts (Total, N = 772; Discovery, N = 236; Validation, N = 536) of 4–7-year-old boys were screened using the Ishihara test for Unlettered Persons and the Neitz Test of Color Vision. ColourSpot was evaluated by testing any child who made an error on the Ishihara Unlettered test alongside a randomly selected control group who made no errors. Psychometric functions were fit to the data and “threshold ratios” were calculated as the ratio of tritan to protan or deutan thresholds. Based on the threshold ratios derived using an optimal fitting procedure that best categorized children in the discovery cohort, ColourSpot showed a sensitivity of 1.00 and a specificity of 0.97 for classifying CVD against the Ishihara Unlettered in the independent validation cohort. ColourSpot was also able to categorize individuals with ambiguous results on the Ishihara Unlettered. Compared to the Ishihara Unlettered, the Neitz Test generated an unacceptably high level of false positives. ColourSpot is an accurate test for CVD, which could be used by anyone to diagnose CVD in children from the start of their education. ColourSpot could also have a wider impact: its interface could be adapted for measuring other aspects of children’s visual performance.

Purpose Autosomal recessive bestrophinopathy (ARB) and vitelliform macular dystrophy (VMD) are distinct phenotypes, typically inherited through recessive and dominant patterns, respectively. Recessively inherited VMD (arVMD) has been reported, suggesting that dominant and recessive BEST1-related retinopathies represent a single disease spectrum. This study compares adVMD, arVMD, and ARB to determine whether a continuum exists and to define clinical and genetic features to aid diagnosis and management. Methods One arVMD patient and nine ARB patients underwent standard ophthalmic examination, imaging, electrophysiology, and genetic assessments. A meta-analysis of reported BEST1 variants was compiled, and clinical parameters were analyzed with regard to inheritance and phenotype. Results Among 10 patients with biallelic BEST1 variants, three novel ARB variants (p.Asp118Ala, p.Leu224Gln, p.Val273del) were discovered. A patient with homozygous p.Glu35Lys was clinically unique, presenting with VMD, including hyperautofluorescence extending beyond the macula, peripheral punctate lesions, and shortened axial-length. A tritan-axis color vision deficit was seen in three of six (50%) of ARB patients. Attempts to distinguish recessively-inherited ARB and dominantly-inherited VMD genotypically, by variant frequency and residue location, did not yield significant differences. Literature meta-analysis with principle component analysis of clinical features demonstrated a spectrum of disease with arVMD falling between adVMD and ARB. Conclusions This study suggests that arVMD is part of a continuum of autosomal recessive and dominant BEST1-related retinopathies. Detailed clinical and molecular assessments of this cohort and the literature are corroborated by unsupervised analysis, highlighting the overlapping heterogeneity among BEST1-associated clinical diagnoses. Tritan-axis color vision deficit is a previously unreported finding associated with ARB.

Purpose Adaptive optics scanning light ophthalmoscopy (AOSLO) imaging in patients with achromatopsia (ACHM) and albinism is not always successful. Here, we tested whether optical coherence tomography (OCT) measures of foveal structure differed between patients for whom AOSLO images were either quantifiable or unquantifiable. Methods The study included 166 subjects (84 with ACHM; 82 with albinism) with previously acquired OCT scans, AOSLO images, and best-corrected visual acuity (BCVA, if available). Foveal OCT scans were assessed for outer retinal structure, outer nuclear layer thickness, and hypoplasia. AOSLO images were graded as quantifiable if a peak cone density could be measured and/or usable if the location of peak density could be identified and the parafoveal mosaic was quantifiable. Results Forty-nine percent of subjects with ACHM and 57% of subjects with albinism had quantifiable AOSLO images. Older age and better BCVA were found in subjects with quantifiable AOSLO images for both ACHM (P = 0.0214 and P = 0.0276, respectively) and albinism (P = 0.0073 and P < 0.0004, respectively). There was a significant trend between ellipsoid zone appearance and ability to quantify AOSLO (P = 0.0028). In albinism, OCT metrics of cone structure did not differ between groups. Conclusions Previously reported AOSLO-based cone density measures in ACHM may not necessarily reflect the degree of remnant cone structure in these patients. Translational Relevance Until AOSLO is successful in all patients with ACHM and albinism, the possibility of the reported data from a particular cohort not being representative of the entire population remains an important issue to consider when interpreting results from AOSLO studies.

Purpose:To investigate acquired color vision deficiency (CVD) using the Rabin cone contrast test (RCCT) in patients with retinal vein occlusion (RVO)., Methods:We retrospectively evaluated 39 patients with macular edema due to RVO who were treated with intravitreal injections of anti-VEGF agents and demonstrated improvement of best-corrected visual acuity to 20/20 Snellen VA or better. The acquired CVD was evaluated by the RCCT and standard pseudo-isochromatic plates-part 2 (SPP-2)., Results:Mean L, M, and S color contrast test (CCT) scores were significantly lower in RVO eyes than in the fellow eyes (L CCTs, 70.0 ± 13.3 vs. 90.0 ± 8.0, respectively, P < 0.01; M CCTs, 85.0 ± 16.6 vs. 95.0 ± 5.7, respectively, P < 0.01; S CCTs, 80.0 ± 21.5 vs. 95.0 ± 7.1, respectively, P < 0.01). Acquired CVD was diagnosed in 25 eyes of 39 patients by the RCCT and in 15 eyes of 39 patients by SPP-2. The RCCT was performed on two different days in 21 patients. It revealed acquired CVD in 17 eyes on the first day and in 10 eyes on the second day. Acquired CVD was improved in 9 eyes, unchanged in 8 eyes, and worsened in 2 eyes., Conclusions:The RCCT revealed eyes with RVO had acquired CVD. Acquired CVD caused by RVO can be improved further in some cases even after recovery of vision to 20/20. The RCCT may be able to quantitatively diagnose acquired CVD status.

In this paper, a novel method to modify color images for the protanopia and deuteranopia color vision deficiencies is proposed. The method admits certain criteria, such as preserving image naturalness and color contrast enhancement. Four modules are employed in the process. First, fuzzy clustering-based color segmentation extracts key colors (which are the cluster centers) of the input image. Second, the key colors are mapped onto the CIE 1931 chromaticity diagram. Then, using the concept of confusion line (i.e., loci of colors confused by the color-blind), a sophisticated mechanism translates (i.e., removes) key colors lying on the same confusion line to different confusion lines so that they can be discriminated by the color-blind. In the third module, the key colors are further adapted by optimizing a regularized objective function that combines the aforementioned criteria. Fourth, the recolored image is obtained by color transfer that involves the adapted key colors and the associated fuzzy clusters. Three related methods are compared with the proposed one, using two performance indices, and evaluated by several experiments over 195 natural images and six digitized art paintings. The main outcomes of the comparative analysis are as follows. (a) Quantitative evaluation based on nonparametric statistical analysis is conducted by comparing the proposed method to each one of the other three methods for protanopia and deuteranopia, and for each index. In most of the comparisons, the Bonferroni adjusted p-values are &lt, 0.015, favoring the superiority of the proposed method. (b) Qualitative evaluation verifies the aesthetic appearance of the recolored images. (c) Subjective evaluation supports the above results.

Sputum colour may mark bacterial involvement in acute exacerbations of chronic obstructive pulmonary disease (COPD). However, whether colour vision deficiency (CVD) in COPD patients could impact the use of sputum colour charts as part of a guide to antibiotic use in exacerbations is unknown. This study used an exploratory mixed-method approach to establish the likelihood that COPD patients will be colour blind and whether this would result in the sputum colour chart being unusable in the context of the patients’ self-management of their condition. CVD is under-reported in primary care and comorbidities in COPD patients increase the risk of acquiring CVD. Participants diagnosed with CVD and risk of acquiring CVD were able to use the sputum colour charts. Colour charts are likely to be usable even in the context of undiagnosed CVD in COPD patients.

Purpose: To determine whether artifacts in optical coherence tomography (OCT) images are associated with the success or failure of adaptive optics scanning light ophthalmoscopy (AOSLO) imaging in subjects with achromatopsia (ACHM). / Methods: Previously acquired OCT and non-confocal, split-detector AOSLO images from one eye of 66 subjects with genetically confirmed achromatopsia (15 CNGA3 and 51 CNGB3) were reviewed along with best-corrected visual acuity (BCVA) and axial length. OCT artifacts in interpolated vertical volumes from CIRRUS macular cubes were divided into four categories: (1) none or minimal, (2) clear and low frequency, (3) low amplitude and high frequency, and (4) high amplitude and high frequency. Each vertical volume was assessed once by two observers. AOSLO success was defined as sufficient image quality in split-detector images at the fovea to assess cone quantity. / Results: There was excellent agreement between the two observers for assessing OCT artifact severity category (weighted kappa = 0.88). Overall, AOSLO success was 47%. For subjects with OCT artifact severity category 1, AOSLO success was 65%; for category 2, 47%; for category 3, 11%; and for category 4, 0%. There was a significant association between OCT artifact severity category and AOSLO success (P = 0.0002). Neither BCVA nor axial length was associated with AOSLO success (P = 0.07 and P = 0.75, respectively). / Conclusions: Artifacts in OCT volumes are associated with AOSLO success in ACHM. Subjects with less severe OCT artifacts are more likely to be good candidates for AOSLO imaging, whereas AOSLO was successful in only 7% of subjects with category 3 or 4 OCT artifacts. These results may be useful in guiding patient selection for AOSLO imaging. / Translational Relevance: Using OCT to prescreen patients could be a valuable tool for clinical trials that utilize AOSLO to reduce costs and decrease patient testing burden.

Achromatopsia (ACHM) is a rare genetic disorder of infantile onset affecting cone photoreceptors. To determine the extent of progressive retinal changes in achromatopsia, we performed a detailed longitudinal phenotyping and genetic characterization of an Italian cohort comprising 21 ACHM patients (17 unrelated families). Molecular genetic testing identified biallelic pathogenic mutations in known ACHM genes, including four novel variants. At baseline, the patients presented a reduced best corrected visual acuity (BCVA), reduced macular sensitivity (MS), normal dark-adapted electroretinogram (ERG) responses and undetectable or severely reduced light-adapted ERG. The longitudinal analysis of 16 patients (mean follow-up: 5.4 ± 1.0 years) showed a significant decline of BCVA (0.012 logMAR/year) and MS (−0.16 dB/year). Light-adapted and flicker ERG responses decreased below noise level in three and two patients, respectively. Only two patients (12.5%) progressed to a worst OCT grading during the follow-up. Our findings corroborate the notion that ACHM is a progressive disease in terms of BCVA, MS and ERG responses, and affects slowly the structural integrity of the retina. These observations can serve towards the development of guidelines for patient selection and intervention timing in forthcoming gene replacement therapies.

Purpose In the absence of pre-admission testing for colour blindness, many of the currently practicing ophthalmologists are colour blind, accordingly their accuracy of distinguishing fine diabetic retinopathy (DR) changes is still unknown. This study aims to assess the accuracy of diagnosing and staging diabetic retinopathy and macular oedema among protonopic, deutronopic and tritanopic ophthalmologists. Methods Cross-sectional assessment of fundus images that were prepared to simulate the appearance in cases of colour blindness. We assessed the accuracy of staging diabetic retinopathy and macular oedema by a retina specialist on colour-blind simulated images. We used randomiser.org to randomly select images to be simulated by the previously validated Vischeck colour blindness simulator. Results A total of 150 simulated images were reviewed, 50 images for each of simulated protanopia, deuteranopia and tritanopia. We found that the accuracy for staging DR and macular oedema for protanope grader were 50% and 60%, respectively. Accuracy within one stage difference for DR and macular oedema were 88% and 90%, respectively. For deuteranopes, 56% and 64% accuracy for DR and macular oedema, respectively. Accuracy within one stage difference for DR and macular oedema were 86% and 90%, respectively. For Tritanope, 62% and 84% accuracy for DR and macular oedema, respectively. Conclusion Colour vision is important for distinguishing fine details during retina assessment in diabetic retinopathy patients. Colour blindness is associated with low accuracy in staging diabetic retinopathy and macular oedema, particularly among protonopic graders, and to a lesser extent in tritanopic graders.

SIGNIFICANCE Protanopia is a color vision deficiency (CVD) that is unacceptable for certain occupations. This study compares simultaneously for the first time the ability of three recently revised or developed clinical tests of color vision with the Ishihara test to diagnose protanopia from other color vision deficiencies. PURPOSE The objectives were to examine the ability of four clinical tests to differentiate (1) between protan and deutan CVDs in patients with protanopia and deuteranopia, and (2) protanopes and deuteranopes as "strong" deficiencies. METHODS The Hardy-Rand-Rittler (4th ed.), City University (3rd ed.), Ishihara, and Mollon-Reffin tests were evaluated against the Oculus Heidelberg Multi-Color anomaloscope for 18 protanopes and 9 deuteranopes. Diagnosis by anomaloscopy was subsequent to administration of screening tests. RESULTS The Ishihara test misdiagnosed all 18 protanopes as having a deutan deficiency. In contrast, the Hardy-Rand-Rittler and Mollon-Reffin tests correctly identified protan CVD in 100% of protanopes. No screening test was able to reliably diagnose protanopia on the basis of a strong protan CVD. CONCLUSIONS The Ishihara test is not suitable for screening for protanopia; its failure to diagnose protanopes as having a protan CVD was far greater than that in previous studies. The Hardy-Rand-Rittler and Mollon-Reffin are the most reliable tests for this purpose. None of the screening tests were able to reliably differentiate dichromacy from strongly anomalous trichromacy.

Purpose Genetic variation in PDE6C is associated with achromatopsia and cone dystrophy, with only a few reports of cone-rod dystrophy in the literature. We describe two pediatric and two adult patients with PDE6C related cone and cone-rod dystrophy and the first longitudinal data of a pediatric patient with PDE6C-related cone dystrophy. Methods This cohort of four patients underwent comprehensive ophthalmologic evaluation at the National Eye Institute's Ophthalmic Genetics clinic, including visual field testing, retinal imaging and electroretinogram (ERG). Next-generation sequencing-based genetic testing was performed and subsequent analysis of the variants was done through three-dimensional protein models generated by Phyre2 and Chimera. Results All cases shared decreased best-corrected visual acuity and poor color discrimination. Three of the four patients had a cone-rod dystrophy, presenting with an ERG showing decreased amplitude on both photopic and scotopic waveforms and a mild to moderately constricted visual field. One of the children was diagnosed with cone dystrophy, having a preserved peripheral field. The children had none to minor structural retinal changes, whereas the adults had clear macular dystrophy. Conclusions PDE6C-related cone-rod dystrophy consists of a severe phenotype characterized by early-onset nystagmus, decreased best-corrected visual acuity, poor color discrimination, progressive constriction of the visual field, and night blindness. Our work contributes with valuable information toward understanding the visual prognosis and allelic heterogeneity of PDE6C-related cone and cone-rod dystrophy.

Purpose: To find out the color vision defects among textile mill workers in Lahore. Study Design: Descriptive cross sectional study. Place and Duration of Study: University of Lahore from June 2019 to December 2019. Methods: Study was done at different textile mills in Lahore, Pakistan. Self-designed proforma was used to record data including age, gender, occupation, any medication or surgery. The workers with best corrected visual acuity of 6/6 and refractive error less than 3.00 D of sphere or astigmatism less than 1 D of cylinder with no history of ocular surgeries were included in the study. Color vision was assessed using Ishihara Isochromatic color plates. Examination of the anterior segment and posterior segment was done by using slit lamp Biomicroscopy and 90 D of condensing lens.Data was entered and analyzed using the SPSS version 22. Results: During this study 1,250 textile mill workers fulfilled the inclusion criteria. Six hundred fifty were males and 600 were females. Only 10 workers were suffering from color vision deficiency, which was 0.8% of the total sample size. All of the color vision deficiency patients were male of different age group. Conclusion: It has been concluded that although textile industry is based on colors, there is no proper color vision examination in our textile sector. Colour vision deficiency awareness should be increased so that everyone in the community is well aware of it. The test of color vision must be made compulsory in pre-employment examination at public and private sector at every Level.

Purpose To examine the foveal avascular zone (FAZ) in patients with congenital achromatopsia (ACHM). Methods Forty-two patients with genetically confirmed ACHM were imaged either with Optovue's AngioVue system or Zeiss's Plex Elite 9000, and the presence or absence of a FAZ was determined. For images where a FAZ was present and could be confidently segmented, FAZ area, circularity index, and roundness were measured and compared with previously published normative values. Structural optical coherence tomography images were acquired to assess the degree of foveal hypoplasia (number and thickness of inner retinal layers present at the fovea). Results A FAZ was present in 31 of 42 patients imaged (74%), although no determination could be made for 11 patients due to poor image quality (26%). The mean ± SD FAZ area for the ACHM retina was 0.281 ± 0.112 mm2, which was not significantly different from the previously published normative values (P = 0.94). However, their FAZs had decreased circularity (P < 0.0001) and decreased roundness (P < 0.0001) compared to the normative cohort. In the patients with ACHM examined here, the FAZ area decreased as the number and thickness of the retained inner retinal layers increased. Conclusions Our data demonstrate that despite the presence of foveal hypoplasia, patients with ACHM can have a FAZ. This is distinct from other conditions associated with foveal hypoplasia, which generally show an absence of the FAZ. In ACHM, FAZ formation does not appear to be sufficient for complete pit formation, contrary to some models of foveal development.

Purpose To investigate the long-term natural history of retinal function of achromatopsia (ACHM). Methods Subjects with molecularly confirmed ACHM were recruited in a prospective cohort study of mesopic microperimetry. Coefficient of repeatability and intraclass correlation coefficient (ICC) of mean sensitivity (MS) were calculated. Best-corrected visual acuity (BCVA), bivariate contour ellipse area (BCEA), contrast sensitivity (CS), MS, total volume (VTOT), and central field volume (V5°) from volumetric and topographic analyses were acquired. Correlation of functional parameters with structural findings from optical coherence tomography (OCT) was performed. Results Eighteen subjects were recruited. Mean follow-up was 7.2 years. The MS test-retest repeatability coefficient was 1.65 decibels (dB), and the ICC was 0.973 (95% confidence interval, 0.837-0.98). Mean MS was similar for right and left eyes (16.97dB and 17.14dB, respectively). A negative significant correlation between logMAR BCVA and the retinal sensitivity indices (MS, VTOT, V5°) was found. A significant negative correlation between logCS and MS, VTOT, and V5° was also observed. BCVA and BCEA improved during follow-up. Mean CS, MS, VTOT, and V5° at final follow-up were similar to baseline. MS was similar between CNGA3- and CNGB3-ACHM. Patients with and without the presence of a foveal ellipsoid zone on OCT had similar MS (16.64 dB and 17.17 dB, respectively). Conclusions We demonstrate a highly reproducible assessment of MS. Retinal function including MS, volumetric indices, and CS are stable in ACHM. Improvement of fixation stability and small changes of BCVA over time may be part of the natural history of the disease.

Patient: Male, 76-year-old Final Diagnosis: Digoxin toxicity • xanthopsia Symptoms: Dyspnea • leg edema • xanthopsia Medication:— Clinical Procedure: Intravenous hydration Specialty: Cardiology Objective: Unusual clinical course Background: Manifestations of digoxin toxicity vary, such as cardiac disturbances and gastrointestinal symptoms, and most are not specific to digoxin toxicity. We report a case of xanthopsia (yellow vision), a rare and relatively specific manifestation of digoxin toxicity, causing traffic accidents. Case Report: A 76-year-old man was admitted to our hospital for treatment of heart failure. He reported that his digoxin dose had been increased from 0.125 mg daily to 0.25 mg daily 3 weeks before admission. His serum digoxin level was 7.3 ng/mL (therapeutic range 0.8 to 2.0). Additional history-taking revealed that he had xanthopsia several days before admission and stopped riding a motorbike because of two traffic accidents. On ophthalmological examination, he had decreased responses on flash, cone, and 30-Hz flicker electroretinograms in both eyes without visual field impairment. Intravenous hydration was initiated and digoxin was withdrawn. Xanthopsia gradually improved along with the decline of serum digoxin levels and disappeared within a week. One month after admission, electroretinography findings were normal. Conclusions: Our case highlights the importance of acknowledging color vision deficiencies due to digoxin toxicity even in the modern era. This condition may increase risk of adverse events because affected patients are less likely to recognize color vision deficiencies.

Deuteranomalous color matching behavior is different from normal because the middle-wavelength sensitive cones contain an abnormal Lʹ pigment instead of the M pigment of the normal observer. However, there is growing evidence that deuteranomalous color experience is not very different from that of normal trichromats. Here, normal and deuteranomalous observers chose monochromatic unique yellow lights. They also chose broadband lights, displayed on a computer monitor, that corresponded to eight special colors: the Hering unique hues (red, yellow, green, blue), and binary colors perceptually midway between them (orange, lime, cyan, purple). Deuteranomalous monochromatic unique yellow was shifted towards red, but all the broadband special color selections were physically similar for normal and deuteranomalous observers. Deuteranomalous special colors, including monochromatic unique yellow, were similar to those of normal observers when expressed in a color-opponent chromaticity diagram based on their own visual pigments, but only if (1) color-opponent responses were normalized to white, and (2) the deuteranomalous diagram was expanded along the r – g dimension to compensate for the reduced difference between deuteranomalous L- and Lʹ-cone photopigments. Particularly, deuteranomalous observers did not choose binary colors with extra r – g impact to overcome their insensitivity along the r – g dimension. This result can only be compatible with the known abnormality of the deuteranomalous Lʹ photopigment if deuteranomalous observers adjust their perceptual representation of colors to compensate for their color vision deficiency.