Clinical color vision testing and correlation with visual function

Retinal damage extends beyond the border of the detached retina in fovea-on retinal detachment

PURPOSE

The aim of this study was to investigate the preoperative and postoperative change in retinal sensitivity in relation to the distance to the retinal detachment (RD) in patients with fovea-on RD.

METHODS

We prospectively evaluated 13 patients with fovea-on RD and a healthy control eye. Preoperatively, OCT scans of the RD border and the macula were obtained. The RD border was highlighted on the SLO image. Microperimetry was used to assess the retinal sensitivity at the macula, the RD border and the retina around the RD border. At 6 weeks, 3 and 6 months postoperatively, follow-up examinations of OCT and microperimetry were performed in the study eye. Microperimetry was performed once in control eyes. Microperimetry data were overlaid on the SLO image. The shortest distance to the RD border was calculated for each sensitivity measurement. The change in retinal sensitivity was calculated as control-study. The relation between the change in retinal sensitivity and the distance to the RD border was assessed using a locally weighted scatterplot smoothing curve.

RESULTS

Preoperatively, the greatest loss in retinal sensitivity was 21 dB at 3° inside the RD which decreased linearly, through the RD border, and reached a plateau of 2 dB at 4°. For 6 weeks and 3 months postoperatively, the greatest retinal sensitivity loss remained at 3° inside the RD but was 4 dB and sensitivity loss decreased linearly to a plateau of 0 dB at 5° outside the RD. At 6 months postoperatively, the greatest sensitivity loss was 2 dB at 3° inside the RD, and decreased linearly to a plateau of 0 dB at 2° outside the RD.

CONCLUSIONS

Retinal damage extends beyond the detached retina. Retinal sensitivity loss of the attached retina decreased drastically as the distance to the RD increased. Postoperative recovery occurred for both attached and detached retina.

Evaluation of the Reddesa Chart, a New Red Desaturation Testing Method, for Optic Neuritis Screening and Grading in Clinical Routine

Background

Optic neuritis usually leads to reduced color sensitivity. Most often, the change of red color, the so-called red desaturation, is tested in clinical routine. The aim of this study was to test the feasibility of the Reddesa chart, a new red desaturation test based on polarization, as a screening method for optic neuropathy.

Methods

A total of 20 patients with unilateral optic neuritis and 20 healthy controls were included in this prospective pilot study. Ophthalmological examination included assessment of best corrected visual acuity (BCVA), slit lamp examination, fundoscopy, testing of relative afferent pupillary defect (RAPD) and red desaturation with the red cup test and the Reddesa chart.

Results

The mean BCVA in the optic neuritis group was 0.76 ± 0.36 in the affected eye (95% of eyes with RAPD, 75% of eyes with difference in the Reddesa test) and 1.28 ± 0.24 in the healthy eye, whereas in the control group, BCVA was 1.14 ± 0.11 in the right eye and 1.15 ± 0.14 in the left eye (none of the eyes with RAPD or abnormal Reddesa test). In our study, the Reddesa test showed a positive predictive value of 100% and a negative predictive value of 80% for detecting optic neuritis.

Conclusion

The Reddesa chart allows to quantify red desaturation and has the potential to be implemented as a screening test in clinical routine.

A Novel Smartphone-Based Color Test for Detection of Color Vision Defects in Age Related Macular Degeneration

Purpose

To evaluate the efficacy of the smartphone-based K-color test to detect color defects in patients with Age-related Macular Degeneration (AMD).

Methods

88 patients (n = 135 eyes) with AMD and 28 controls (n = 53 eyes) underwent color testing with the Hardy–Rand–Rittler (H-R-R), the K-color test, and the Ishihara test. The K-color test presents randomized colored shapes in decreasing steps of intensity, providing also a record system for result tele-transmission. Sensitivity, specificity, and reliability were examined to investigate the validity of the novel test. 26 participants with AMD also completed a questionnaire regarding the feasibility of the test.

Results

Linear mixed-effects models indicated a significant difference (p < 0.001) between AMD and normal eyes. The areas under the curve (AUC) were estimated to be 0.897 [95% CI: 0.841–0.952], 0.943 [95% CI: 0.901–0.984], and 0.931 [95% CI: 0.886–0.977] for the red, green, and blue color, respectively. Based on the H-R-R, the sensitivity of the test was 0.79, 0.90, and 0.95 for the red, green, and blue colors, respectively, and specificity was 0.88 for all colors. The new test recognized more abnormal cases than the Ishihara (sensitivity of 0.98 and 1.0 and specificity of 0.48 and 0.38 for red and green colors, respectively). Test-retest reliability was found to be high for the red [ICC = 0.996 (0.990–0.999)], green [ICC = 0.974 (0.929–0.990)], and blue [ICC = 0.992 (0.981–0.997)] colors. The majority of the asked participants stated that they could easily perform the test.

Conclusion

The K-color test was found to be sensitive and specific in detecting color defects in AMD patients. The K-color test may serve as a useful tool both for patients and their physicians.

Visual function tests for glaucoma practice - What is relevant?

Glaucoma represents one of the most important ocular diseases causing irreversible ganglion cell death. It is one of the most common causes of visual impairment and morbidity in the elderly population. There are various tests for measuring visual function in glaucoma. While visual field remains the undisputed method for screening, diagnosis, and monitoring disease progression, other tests have been studied for their utility in glaucoma practice. This review discusses some of the commonly used tests of visual function that can be routinely used in clinics for glaucoma management. Among the various modalities of testing visual function in glaucoma, this review highlights the tests that are most clinically relevant.

Application of Blue Filters Increases the Usefulness of Moreland Test in Anomaloscopic Color Vision Assessment for Blue-Green Color Range

The effect of blue light filters on the anomaloscopic examination was analyzed. Thirty subjects (18–43 y, 20 female, 10 male) without color vision disorders were examined in 4 filter conditions: no filter (F-0), Blue Control Hoya (F-BC), Med-1 JZO (F-Med1) and 450 Eschenbach (F-450). Both Rayleigh test (red–green axis) and Moreland test (blue–green axis) were performed. Application of F-BC filter shows negligible effect on color vision perception in both tests. Contrary to this, the application of strong F-450 filter causes significant shift in Moreland test towards tritanopy and the decrease in correlations of Moreland parameters with Rayleigh test parameters. The application of medium strong F-Med1 filter causes the slight shift in Moreland test towards the center of the Moreland scale and increases the Spearman correlations between Moreland and Rayleigh test parameters. This observation suggests that the about 15–40% reduction of blue diode intensity in the Moreland test may be beneficial in detecting mild changes in color vision perception in the blue-green axis and may improve its usefulness in evaluating the color vision perception disorders accompanying different illnesses, such as diabetes, glaucoma, neuritis optica, or cataract. The discussion concerning the modifications of Moreland test construction is also presented.

Genes Relevant to Tissue Response to Cancer Therapy Display Diurnal Variation in mRNA Expression in Human Oral Mucosa

Background:

To address a critical gap for application of cancer chronotherapy of when would be the best time(s) for treating an individual cancer patient, we conducted a pilot study to characterize diurnal variations of gene expression in oral mucosal tissue, which is vulnerable to damage from cancer therapies.

Methods:

We conducted RNA-seq assay on individual oral mucosal samples collected from 11 healthy volunteers every 4 hours (6 time points). Using a cosine-based method, we estimated the individual and average values of peak-time and amplitude for each gene. Correlations between gene expression peak-times and age was examined, adjusting for individual’s sleep timing.

Results:

Among candidate gene pathways that are relevant to treatment response, 7 of 16 genes (PER3, CIART, TEF, PER1, PER2, CRY2, ARNTL) involved in circadian regulation and 1 of 118 genes (WEE1) involved in cell cycle regulation achieved p-value ≤ 0.1 and relative amplitude>0.1. The average peak times were approximately 10:15 for PER3, CIART and TEF, 10:45 for PER1, 13:00 for WEE1, PER2 and CRY2, and 19:30 for ARNTL. Ranges in peak times across individuals differed by gene (e.g., 8 hours for PER1; 16.7 hours for WEE1). Older people had later peak times for PER1 (r = 0.77, p = 0.03) and PER3 (r = 0.69, p-value = 0.06).

Conclusion:

In oral mucosa, expression of some genes relevant to treatment response displayed diurnal variation. These genes may be candidates for development of biomarkers for optimizing individual timing of cancer therapy using non-invasively collected oral mucosa.

Visual Acuity Inadequately Reflects Vision-Related Quality of Life in Patients After Macula-Off Retinal Detachment Surgery

Purpose

To determine the impact of postoperative visual function on the vision-related quality of life (VRQoL) in patients after anatomically successful surgery for macula-off rhegmatogenous retinal detachment (RRD) and to propose a classification to grade the extent of macular detachment using preoperative optical coherence tomography (OCT) scans.

Methods

This prospective study evaluated 48 patients. At 12 months after surgery, visual function assessments were as follows: metamorphopsia (M-CHARTS), aniseikonia (New Aniseikonia Test), best corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS]), low contrast BCVA (10% ETDRS), color vision (Hardy Rand Rittler), and stereopsis (Titmus Fly). VRQoL was assessed by the National Eye Institute Visual Functioning Questionnaire-25 (NEIVFQ-25). Associations between visual function parameters and NEIVFQ-25 scores were evaluated. Preoperative OCT-scans were classified into six stages according to the extent of macular detachment based on an ETDRS-grid: incomplete perifoveal detachment (1), incomplete parafoveal detachment (2), incomplete foveal detachment (3), complete foveal detachment (4), complete parafoveal detachment (5), and complete perifoveal detachment (6).

Results

General vision and driving were the lowest scoring categories. General vision had the strongest correlation with low contrast BCVA (r = −0.41, P = 0.002), while driving had the strongest correlation with stereopsis (r = −0.39, P = 0.008). All macular detachments were graded stage 3 or beyond. Patients with stage 3 macular detachments had the highest visual function values compared to the other stages. The highest percentage of patients with metamorphopsia, aniseikonia and BCVA>0.1 logMAR was found in stages 5 and 6.

Conclusions

Macula-off RRD particularly affects general vision and driving. The extent of macular detachment is a potential predictor for visual function and can be graded using the proposed classification.

The effect of reduced contrast sensitivity on colour vision testing

OBJECTIVE

To assess the effect of reduced contrast sensitivity on three commonly used colour vision tests in order to establish key discrepancies that may be relevant for clinical practice.

METHODS

A prospective non-interventional clinical study of colour vision testing using three commonly used devices: Ishihara and Hardy-Rand-Rittler (H-R-R) pseudoisocochromatic plate tests, and Farnsworth D-15 arrangement test performed under progressively reduced contrast sensitivity conditions achieved with a neutral density filter bar.

RESULTS

The Pelli-Robson contrast sensitivity (PRCS) at which 5% of the population should first experience a 10% reduction in colour vision testing from baseline was calculated for each of the three colour vision devices: Farnsworth D-15 test: 1.81 log contrast sensitivity (CS), H-R-R test: 1.69 log CS, and Ishihara test: 1.34 log CS. Single factor repeated measures analyses, conducted separately at each contrast sensitivity level, revealed no difference between the colour vision testing devices at PRCS ≥1.80 log CS (P ≥ 0.367). However, in all PRCS ≤1.65 log CS, the differences were statistically significant (all P ≤ 0.004), demonstrating a significantly lower percentage of errors in the Ishihara test compared with both the Farnsworth D-15 (P < 0.023) and H-R-R (P < 0.035) tests.

CONCLUSIONS

At high contrast sensitivities, all colour vision tests function almost equally; however, at decreased levels of contrast sensitivity, H-R-R and Farnsworth D-15 are more greatly affected.

A proposed correction in the weighted method to score the Ishihara test

Objective

Ishihara test is a color vision test, whose results consider that all plates of the test have the same weighting. Rodriguez-Carmona et al. (Aviat Space Environ Med 83:19–29, 2012) proposed an equation to quantify the Ishihara test results (severity index), which took an account the rate of hits from the different plates of the test considering the performance of trichromat or colorblind population. We proposed a correction in Rodiguez-Carmona’s equation for the severity index. We evaluated 60 normal trichromats and 107 subjects with congenital color deficiency. We calculated three indexes to quantify the results of each subject: a non-weighted index, a weighted index similar to the Rodriguez-Carmona et al., and a weighted index modified which combined the hit frequency for each plate in a trichromat population and of the error reading frequency for each plate in color-blind populations.

Results

Compared to the non-weighted evaluation, the weighted index was reduced by 22.95%, 32.92%, and 35.38% from trichromats, protan and deutan groups, respectively. Receiver Operating Characteristics (ROC) analysis showed perfect performance of the classifier for all metrics to measure the Ishihara test results. The proposal correction changed significantly the value of the index, but the overall benefits were small.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4320-2) contains supplementary material, which is available to authorized users.

Comparison of a Smartphone Application with Ishihara Pseudoisochromatic Plate for Testing Colour Vision

The Eye Handbook (EHB) is the most frequently downloaded smartphone application with diagnostic tools for eye-care providers. However, limited data exists validating the EHB test to gold standard colour vision testing. EHB and Ishihara colour vision tests were evaluated and compared under simulated colour vision loss through use of image processing software. Images of both tests were processed through ImageJ to 32 bit-grey scale and blue channel under split RBG channel to model total colour vision loss and red-green (R-G) deficiency, respectively. Two colour plates differentiated R-G deficiency from total colour blindness in EHB compared with eight Ishihara plates. Without colour information, correct numerals were identified in 3.5/15 EHB plates converted to 32-bit greyscale, versus 1/16 in Ishihara. We conclude EHB may underestimate colour vision loss severity in persons with normal contrast sensitivity compared to Ishihara. Eye-care providers need to be aware of the potential inconsistency compared to standardised methods, including limitations in differentiating patients with R-G colour deficiencies from total colour blindness.

Diffuse Colour Discrimination as Marker of Afferent Visual System Dysfunction in Amyotrophic Lateral Sclerosis

Abnormalities of the inner and intermediate retinal structures in patients with amyotrophic lateral sclerosis (ALS) have been described using optical coherence tomography and histopathology. Colour vision is a potential marker of these structural changes. The purpose of this study is to test the hypothesis that colour vision impairment is associated with ALS. Monocular (right eye) colour vision was assessed in subjects with definite or probable ALS (n = 25, aged 50-80 years) and control (n = 21, aged 46-89 years) subjects with corrected near visual acuity of at least 20/40 using the L'Anthony D15 color test (desaturated), scored by c-index, a measure of diffuse colour discrimination. Of ALS subjects, 16/25 (64%) had impaired colour vision (c-index >1.8). Comparing with our normal subjects and accounting for age, 72% (n = 18) of ALS subjects had colour vision below the 50th percentile, 52% (n = 13) had colour vision below the 25th percentile, 24% (n = 6) had colour vision below the 10th percentile, and 8% (n = 2) had colour vision below the 2nd percentile. In multivariate models of ln(c-index) and age, the intercept was higher and the slope was flatter in ALS subjects, suggesting that colour vision deficits are more prominent in younger ALS patients. Diffuse colour discrimination deficits are detected in ALS subjects at younger ages than in control subjects. Further study is needed to confirm these findings and to determine if the ALS colour discrimination abnormalities correlate with structural markers of retinal involvement and ALS disease severity.

Effects of Contrast Sensitivity on Colour Vision Testing

This study analyses how contrast sensitivity loss affects colour vision (CV) testing. Eleven participants were scored while cycling through randomly arranged pictures of CV tests with varying levels of contrast changes applied. Hardy-Rand-Rittler (HRR) scores declined significantly at each successive decrease in contrast level after the highest setting (p < 0.004). HRR scores were also lower than those for Ishihara and Farnsworth D-15 tests at two contrast settings (p < 0.01). Contrast changes had the greatest impact on HRR scores, indicating that this test may not be an accurate reflection of CV in patients with contrast sensitivity loss.

A method for identifying color vision deficiency malingering

PURPOSE

To propose a new test to identify color vision deficiency malingering.

METHODS

An online survey was distributed to 130 truly color vision deficient participants and 160 participants willing to simulate color vision deficiency. The survey contained three sets of six color-adjusted versions of the standard Ishihara color plates each, as well as one set of six control plates. The plates that best discriminated both participant groups were selected for a "balanced" test emphasizing both sensitivity and specificity. A "specific" test that prioritized high specificity was also created by selecting from these plates. Statistical measures of the test (sensitivity, specificity, and Youden index) were assessed at each possible cut-off threshold, and a receiver operating characteristic (ROC) function with its area under the curve (AUC) charted.

RESULTS

The redshift plate set was identified as having the highest difference of means between groups (-58%, CI: -64 to -52%), as well as the widest gap between group modes. Statistical measures of the "balanced" test show an optimal cut-off of at least two incorrectly identified plates to suggest malingering (Youden index: 0.773, sensitivity: 83.3%, specificity: 94.0%, AUC of ROC 0.918). The "specific" test was able to identify color vision deficiency simulators with a specificity of 100% when using a cut-off of at least two incorrectly identified plates (Youden index 0.599, sensitivity 59.9%, specificity 100%, AUC of ROC 0.881).

CONCLUSIONS

Our proposed test for identifying color vision deficiency malingering demonstrates a high degree of reliability with AUCs of 0.918 and 0.881 for the "balanced" and "specific" tests, respectively. A cut-off threshold of at least two missed plates on the "specific" test was able to identify color vision deficiency simulators with 100% specificity.