Evaluating the level of visual acuity to minimise false-positives in different colour vision tests.

CLINICAL RELEVANCE: Accurate colour vision assessment is important in clinical settings to minimise false-positive errors and enhance the reliability of diagnoses outcomes. BACKGROUND: Colour vision testing is valuable in assessing the visual system, particularly given the high proportion of individuals with poor vision. This study aimed to determine the minimum visual acuity level required to perform a colour-vision test without errors. METHODS: After fogging the right eyes of 52 healthy participants using plus lenses to 1.60 logMAR, vision was evaluated using Ishihara, Hardy - Rand - Rittler Standard Isochromatic, Waggoner Pseudo-isochromatic, City University, Waggoner Computerised, and Farnsworth D-15 tests. Participants then completed these tests at lower fogging degrees (in 0.1-logMAR intervals). The acuity at which 5% of the tested population was considered abnormal was determined. RESULTS: Significant differences were found in the average visual acuity required to perform colour vision tests without errors (p < 0.05). The Waggoner Computerized test required the highest average visual acuity among the tests utilised. The Farnsworth D-15 test yielded the highest logMAR values. No significant differences were observed between the Waggoner Pseudo-isochromatic test and Hardy - Rand - Rittler Standard Isochromatic, Ishihara, and Farnsworth D-15 tests (p > 0.05). Additionally, no significant differences were found between the Ishihara and Hardy - Rand - Rittler tests (p > 0.1) or between the Waggoner Computerized and City University tests (p = 0.11). Colour vision testing maintained an accuracy ≤ 1.0 logMAR with the Ishihara and Hardy - Rand - Rittler tests, 1.1 logMAR with the Waggoner Pseudo-isochromatic and Farnsworth D-15 tests, and 0.9 logMAR with the Waggoner Computerized and City University tests. CONCLUSIONS: Insights are provided into the visual acuity thresholds required for accurate colour vision testing, which can serve as a basis for future research and provide a reference for clinical practice in this field.

Assessment of tear film parameters post-treatment with commercial eyelid cleaning wipes: a pilot study.

AIM: To investigate the short-term effects of commercially available eyelid-cleaning wipes on film parameters. METHODS: This study enrolled 48 healthy participants aged 20-35y (both males and females). Clinical assessment included the Ocular Surface Disease Index (OSDI) questionnaire, non-invasive tear break-up time (NITBUT), tear meniscus height (TMH), and lipid layer pattern (LLP). Based on these initial results, participants were categorized as either non-dry eye or dry eye. Participants in each group were randomly allocated to either Blephaclean® or Systane® treatments. Changes in NITBUT, TMH, and LLP levels before and after lid wipe treatment were assessed. RESULTS: The dry eye group exhibited significantly higher OSDI scores and lower NITBUT and TMH levels than in the non-dry eye group (P<0.001). Following the application of eyelid wipes (Systane® wipes), dry eye subjects experienced a significant improvement in NITBUT levels (P=0.0014) compared to the non-dry eye individuals. Although the remaining participants showed a marginal increase in TMH and NITBUT levels, these changes did not achieve statistical significance (P>0.05). Similarly, the LLP levels were significantly improved with Systane® (P<0.001) post-treatment compared to individuals in the non-dry eye group. However, the dry eye subjects showed higher post-treatment LLP levels than the untreated group (P<0.02). CONCLUSION: The short-term effects of Systane® eyelid wipes on tear film parameters suggest their effectiveness in dry eye disease. Nonetheless, further exploration of their long-term impact is essential to justify their cost effectiveness and efficacy in treating both aqueous deficiency and evaporative dryness.

Age-related changes in reading performance in normally sighted Arabic-speaking adults.

CLINICAL RELEVANCE: Reading performance is important for evaluating near vision and predicting and prescribing near-vision correction. There is a significant gap in the literature on Arabic reading performance and its associated effects. BACKGROUND: Normative data from control participants serve as the baseline for future studies involving groups with specific characteristics. This study aimed to assess baseline measures of Arabic reading performance. METHODS: In total, 428 normally sighted adults aged 19-83 years read the Balsam Alabdulkader - Leat chart to measure their reading performance. The participants were divided into five age groups. The outcome measures were the maximum reading speed in standard-length words per minute, critical print size, reading acuity, and reading accessibility index. RESULTS: The average reading performance measures were as follows: 171 ± 27 standard-length words per minute for maximum reading speed, 0.01 logarithm of the minimum angle of resolution for critical print size, -0.17 logarithm of the minimum angle of resolution for reading acuity, and 1.02 for the accessibility index. There were significant differences among the age groups, indicating a dependency on age and showing a plateau for the young adult group and a decline with age. The accessibility index had an almost perfect correlation with maximum reading speed and a weak but significant relationship with reading acuity and critical print size. CONCLUSION: Arabic exhibits an age-dependent trend in reading speed. However, owing to differences in orthography, visual demands, and reading strategies, the magnitude of the decrease and increase differs, potentially accounting for the variations between languages, especially when compared to English. This study serves as a foundation for future studies on Arabic reading performance. Future studies should examine the reading performance in patients with low vision, study the effects of common diseases on reading ability, evaluate the effectiveness of reading devices, and assess improvements in vision rehabilitation.

Can chromatic text/background improve Arabic reading performance?

PURPOSE: Colors have been shown to improve reading performance; however, the effect of colors on Arabic orthography has not been studied. This study aimed to design and create a chromatic acuity chart to evaluate the effect of chromatic contrast on Arabic reading performance. METHODS: Color selection for the newly developed chromatic acuity chart was based on the contrast between the L, M, and S cones. The colors were chosen to have a luminance of approximately 13.6 cd/m2 with red text on a green background. A Pantone color guide set was used to choose the colors. Fifteen healthy individuals aged 19-27 years were recruited. Reading performance was measured using the newly developed red-green (R-G) chart and compared with the original achromatic Balsam Alabdulkader-Leat (BAL) chart with a luminance of 95 cd/m2. The outcomes were maximum reading speed in standard-length words per minute (SLWPM), reading acuity (RA), and critical print size (CPS). RESULTS: The mean R-G SLWPM of 201 wpm was similar to that of the BAL chart (P < 0.05). The mean RA for the R-G chart was - 0.05 logMAR and - 0.20 logMAR for the BAL chart (P < 0.05). The CPS for the R-G chart was 0.36 logMAR, significantly higher than the original chart of 0.17 logMAR (P < 0.05). CONCLUSION: This study showed that the reading performance for a text that varies only in chromatic contrast along the R-G axis reduces the reading performance for CPS and RA. Individuals showed an approximate decline of two lines on an Arabic continuous text chart compared with a high-contrast achromatic chart. This information can be used to further develop a set of near-reading charts that can efficiently determine whether there is a differential loss in chromatic and achromatic sensitivity in patients with various vision disorders.

Visual resolution under photopic and mesopic conditions in patients with Sjögren's syndrome.

AIM: To focus on different visual resolution tasks under photopic and mesopic conditions in Sjögren's syndrome patients compared to age-matched healthy controls. METHODS: The visual resolution measurements included high and low visual acuities and contrast sensitivity functions. These tests were conducted under photopic and then mesopic conditions. Twenty-one Sjögren's syndrome patients and 21 aged-matched healthy volunteers completed all the measurements in this study. RESULTS: Sjögren's syndrome patients have greater impairment in contrast sensitivity than standardized visual acuity. This reduction was significant under the mesopic condition. Also, Sjögren's syndrome patients treated with pilocarpine suffer more than patients without pilocarpine treatment under low light conditions. CONCLUSION: Sjögren's syndrome patients shows greater impairment in different visual resolution tasks due to dry eye symptoms.

Clinical analysis of the Konan-Waggoner D15 color vision test using the Surface-Pro display.

This work expands on our previous comparison of the Konan-Waggoner D15 (KW-D15) and Farnsworth D15 (F-D15). Sixty subjects with normal color vision and 68 subjects with a red-green color vision defect participated in the study. The KW-D15 had good agreement with the F-D15 for both pass/fail and classification across all failure criteria. The agreement was slightly better if subjects had to pass on 2/3 trials compared with just the first trial. The KW-D15 is an adequate substitute for the F-D15, with the caveat that the KW-D15 might be slightly easier to pass than the F-D15 for deutans.

Evaluation of the Third edition of the City University Colour Vision Test.

INTRODUCTION: The 3rd edition of the City University Colour Vision Test (CUT) was originally based on the Farnsworth-Munsell D-15 test (D15). The first part of the test is for detecting a defect, and the second part is used to diagnose the type and severity of the defect. This study evaluates the CUT 3rd edition relative to the Ishihara and the D15 colour vision tests. METHODS: Fifty nine colour vision normal subjects and 60 subjects with a congenital red-green colour vision defect were recruited. Subjects were tested with the Ishihara and CUT tests. Subjects who failed the Ishihara also performed the D15 test. RESULTS: The agreement between the Ishihara and CUT screening plates was marginally higher when using the CUT failure criterion of >1 error compared with using >2 errors. If the diagnostic plates were included with the screening plates in determining the pass/fail outcomes, the agreement between the Ishihara and CUT was high, with a first-order agreement coefficient (AC1) of 0.90. The AC1 coefficient agreement between the D15 and CUT diagnostic plates in terms of pass/fail was 0.81 when using the D15 failure criteria of >1 or >0 crossing. CONCLUSION: The level of agreement between the 3rd edition of the CUT and D15 was lower than the 2nd edition of the CUT. The primary reason for the lower agreement of the 3rd edition of the CUT was that it had a lower specificity relative to the D15 compared to the 2nd edition. Although the CUT predictive value for failing the D15 is over 90%, the predictive value for passing shows that 19%-25% of patients who pass the 3rd edition of the CUT test will fail the D15. The 3rd edition tends to misclassify protans as deutans or cannot classify the type of defect relative to the D15 and Ishihara.

Evaluation of the Waggoner computerized D15 color vision test using an iPad device.

The W-D15 test, a computerized variant of the F-D15 test, is used to determine whether an individual with a color vision defect can safely perform color-related tasks. This study evaluated the performance of the W-D15 test using an iPad. Fifty-nine color normal and 61 color vision defect subjects participated. Participants were screened based on the Ishihara, City University Test, and Waggoner PIP24 tests. Different failure criteria of the D15 tests were considered. The pass/failure agreement between the two tests was relatively appropriate, with a κ-coefficient ≥0.8, for all failure criteria. The W-D15 could be an appropriate substitute for F-D15 using an iPad.

Pupil light reflex in Parkinson's disease patients with and without freezing of gait symptoms.

PURPOSE: Freezing of gait (FOG) is considered as a motor disorder that affects some Parkinson's disease (PD) patients; however, sensory systems may also be involved in FOG. The pupil light reflex (PLR) is a reliable measure of the autonomic nervous system. Different dilation and constriction pupil parameters may be used to investigate the integrity of the autonomic nervous system in PD patients with and without FOG symptoms. This study aimed to look at the integrity of autonomic nervous system and to investigate the nonmotor functions mediated by the cholinergic system in Parkinson's patients with and without FOG symptoms. METHODS: Constriction and dilation pupil light reflexes were measured by using a handheld pupillometer. Twenty-two patients with FOG symptoms, 25 patients without FOG symptoms, and 25 aged-matched healthy controls participated in this study. RESULTS: The results showed that most of the constriction parameters and dilation latency of both patient groups differed significantly from healthy controls. FOG patients showed larger pupil size under light condition and larger deficits in constriction latency than nonFOG patients. Both the groups of PD patients had longer dilation latencies than healthy controls. CONCLUSION: This study suggests that the cholinergic autonomic nervous system is affected in PD patients more than the adrenergic system. FOG patients had larger impairments in nondopaminergic mediated functions such as pupil light reflexes, which suggests that FOG patients have greater impairment in functions that involve cholinergic neurotransmitters.

Changing vergence function in persons with Parkinson's disease and convergence insufficiency.

Individuals with Parkinson's disease and convergence insufficiency were assigned vergence training. After two months, average positive fusional vergence increased and average near point of convergence decreased. Vergence can be improved with training in persons with Parkinson's disease who also have convergence insufficiency.

Visual processing speed in freezing and non-freezing Parkinson's disease patients.

INTRODUCTION: Parkinson's disease patients are usually characterized by body motor dysfunction due to dopaminergic reduction in the central nervous system. Freezing of gait is a motor disorder that affects certain Parkinson's disease patients. However, it is hypothesized that non-motor functions mediated by the cholinergic system are also involved in developing freezing of gait. Visual information processing speed, or inspection time is independent of the motor response, and can be used a reliable measure of the cholinergic system integrity. OBJECTIVE: Inspection time can be used to investigate whether Parkinson's disease patients with freezing of gait symptoms have a larger impairment in cholinergic mediated functions than those patients who have no freezing of gait symptoms and healthy controls. METHODS: The inspection time was determined by a simple length discrimination task. Twenty-two Parkinson's disease patients with freezing of gait, 25 Parkinson's disease patients without freezing of gait, and 25 aged matched healthy controls participated in the study. RESULTS: Based on the log values of IT score, Parkinson's disease patients with freezing of gait symptoms had statistically significant slower inspection times (mean of 1.793 ms) than Parkinson's disease patients without freezing of gait (mean of 1.655 ms) and healthy controls (mean of 1.523 ms). Inspection times for the Parkinson's disease patients without FOG symptoms were also significantly slower than healthy controls. CONCLUSION: The results of this study support the hypothesis that the cholinergic system integrity is affected more in Parkinson's disease patients with freezing of gait symptoms.

Stereopsis and ocular alignment in Parkinson's disease patients with and without freezing of gait symptoms.

BACKGROUND: Parkinson's disease patients are classically described by having motor disorder symptoms. Freezing of gait is one of these motor symptoms that presents in some of these patients. Even though freezing of gait is classically considered as motor dysfunction, it is now widely accepted that deficits in other sensory systems, for example visual system, may lead or contribute to freezing of gait. The purpose of this study is to characterise some of the binocular vision functions in freezing of gait patients, non-freezing of gait Parkinson's disease patients and age-matched healthy controls. METHODS: Binocular vision measurements included local and global stereopsis using different clinical stereo tests, along with fixation disparity and fixation disparity curves. The fixation disparity measures were primarily an assessment of the vergence motor system, and the clinical stereo tests assess the combined effects of motor and sensory aspects of binocular vision. Twenty-two freezing of gait patients, 25 non-freezing of gait patients, and 25 aged-matched healthy controls completed all of the measurements in this study. RESULTS: The freezing of gait group had worse stereopsis than the non-freezing of gait group, and the non-freezing of gait group had worse stereopsis than the healthy controls. The impairment of global stereopsis was more common than local stereopsis in Parkinson's disease patient groups. The reduction in stereopsis among Parkinson's disease patients was not associated with fixation disparity. CONCLUSIONS: Results from this study clearly indicate that the freezing of gait patients group has a greater loss in stereopsis than the other two groups, especially for the global tests. Whether these impairments are contributing to the freezing of gait or just associated with freezing of gait is uncertain.

Repeatability of Associated Phoria Tests.

PURPOSE: H.J. Haase developed a set of tests for measuring associated phoria and stereopsis using a variety of different targets for each. This testing method is known as the MKH-Haase method and it is used commonly in Germany. The aim of this study was to investigate the test-retest repeatability of the distance and near associated phoria tests for the MKH-Haase charts and other clinical tests. METHODS: Horizontal and vertical associated phorias were measured at distance and near for 34 symptomatic and 40 asymptomatic participants with different tests. The tests are Cross, Pointer, Double Pointer, and Rectangle tests of MKH-Haase charts at distance and near. The other common tests include the Mallett Test and the American Optical (AO) Slide at distance. At near, there are the Mallett Test, the AO Card, the Saladin Card, the Wesson Card, and the Sheedy Disparometer. RESULTS: The 95% limits of agreement for all of the distance horizontal values for the symptomatic group were within ±1.25, except for the AO Slide limits, which were larger by 0.43. The limits of agreement for the asymptomatic group were within ±0.875. At near, the 95% limits of agreement for most of the horizontal associated phoria tests were ±2.00. The exception was the symptomatic group's Sheedy Disparometer limits, which were -4.25 to 5.75. Except for the Disparometer values for the asymptomatic group, the mean between-session differences were not statistically significant different from zero based on the 95% confidence interval. The asymptomatic group's mean Disparometer value was less eso at the second session. The 95% limits of agreement for all of the vertical values at distance and near for both groups were very narrow (i.e., within ±0.375). CONCLUSIONS: Most of the tests showed good repeatability for both subject groups at distance and near, except for the Sheedy Disparometer. The reason for the lower repeatability could be the design of the Disparometer.