Exploring the impact of optical corrections on visual functions in myopia control-a scoping review.

PURPOSE: Myopia is controlled optically with peripheral defocus spectacles, multifocal contact lenses, or orthokeratology lenses. However, it is unknown which optical correction will improve visual performance. This scoping review aimed to identify and summarize studies on various visual functions using optical corrections for myopia control. METHODS: To develop the search strategy, population (Myopia), concept (visual performance), and context (unrestricted race/region) were used. PubMed, SCOPUS, Cochrane Library, and Web of Science databases were searched using the keywords myopia, contrast sensitivity, high and low contrast visual acuity, stereopsis, and optical correction of myopia control. This scoping review protocol was registered in the Open Science Framework registry and followed the framework for scoping review outlined by the Joanna Briggs Institute. RESULTS: Eight studies (n = 8) met the inclusion criteria and were included in the review. Four were conducted in Europe, two were conducted in China, and one was conducted in Japan and Singapore. Five studies were randomized controlled trials, out of which three used contact lenses and two studies used peripheral defocus spectacles lenses. Studies ranged from one day to 2 years. Three studies that used orthokeratology lenses were prospective study designs. Among the studies that used orthokeratology lenses and contact lenses, two studies measured the contrast sensitivity function with CSV1000 (Vector Vision) under mesopic and photopic conditions, with and without glare. Two studies measured the central and peripheral contrast sensitivity using psychophysics experiments. High and low contrast visual acuity was measured using the Freiburg Vision Test (n = 1) and ETDRS charts (n = 3), and stereopsis was assessed using a random dot stereogram (n = 1). The studies showed a reduction in central and peripheral contrast sensitivity function and low contrast acuity when treated with multifocal contact lenses, orthokeratology lenses, and peripheral defocus lenses compared with single-vision lenses. CONCLUSION: This scoping review found a reduction in central and peripheral contrast sensitivity function, as well as low contrast visual acuity when using various optical corrections for myopia control, while high-contrast visual acuity remained the same. The impact of visual functions may not influence the effectiveness of myopia control. Eye care practitioners should provide awareness to the parent and patient population about the potential visual impact of recent designs for optical corrections of myopia control.

Visual Field Evaluation Using Zippy Adaptive Threshold Algorithm (ZATA) Standard and ZATA Fast in Patients With Glaucoma and Healthy Individuals.

Purpose: To evaluate visual fields obtained with Zippy Adaptive Threshold Algorithm (ZATA) Standard and ZATA Fast from patients with glaucoma and healthy individuals. Methods: Fifty-five patients with glaucoma (median mean deviation [MD], -7.6 dB; interquartile range [IQR], -15.3 to -2.6 dB) and 22 healthy participants (median MD, -0.6 dB; IQR, -1.7 to 0.2 dB) performed ZATA Standard and ZATA Fast tests on a Henson 9000 perimeter and Swedish Interactive Thresholding Algorithm (SITA) Standard and SITA Fast tests on a Humphrey Field Analyzer. Tests were repeated within 90 days (median, 14 days; range, 7-26 days) to evaluate the test-retest variability. Results: The mean difference between the MD of the ZATA Standard and SITA Standard tests was 1.7 dB (95% confidence interval [CI], 0.9-2.4). Between ZATA Fast and SITA Fast, it was 0.9 dB (95% CI, 0.2-1.5 dB). Although there were systematic differences between the distributions of sensitivity estimates with ZATA and SITA, they did not affect the overall representation of damage by these tests. ZATA Standard and ZATA Fast were approximately 30% and 6% faster, respectively, than the corresponding SITA tests. Conclusions: ZATA Standard and ZATA Fast are suitable for clinical practice. However, differences between ZATA and SITA tests suggest that they should not be used interchangeably when patients with glaucoma are followed over time. Translational Relevance: This study examined the characteristics of ZATA visual field tests in a clinical population, and it supports the adoption of these tests for assessing patients with glaucoma.

Knowledge, perception and practice towards blue-blocking lenses among optometrists.

CLINICAL RELEVANCE: There is a lack of clinical guidelines in India for the prescription of blue-blocking lenses. Therefore, the practice trends will depend on practitioners' knowledge, attitude, and perception. BACKGROUND: Exposure to blue light with increased use of light-emitting diode (LED) lights and digital devices along with the commercial availability of blue blocking lenses has warranted the need to understand the factors that influence the prescription of blue blocking lenses among eye care practitioners. Hence, we aim to assess knowledge, perception, and practice pattern of blue blocking lenses among Indian optometrists. METHODS: This cross-sectional online survey was conducted among Indian Optometrists. The survey was distributed through various social groups of optometrists and state associations. The questionnaire had four main domains with 29 items in total. The four major domains were knowledge, practice, perception and demographic details on education. Descriptive analysis and logistic regression were performed to study the impact of these domains on the prescription of blue block lenses. RESULTS: Out of 341 responses, 247 were included for analysis as per study criteria. About 50% (n = 123) of the participants had appropriate knowledge about blue light. Blue-blocking lenses were prescribed always or most of the time by 52% (n = 130) of the participants. The odds of prescribing blue blocking lenses were higher among practitioners who considered blue light as an important factor in causing computer vision syndrome (OR 3.77, 95% CI: 1.33-10.69, P = 0.01) or if they considered there is adequate published evidence (OR 3.95, 95% CI: 1.58-9.87, P = 0.003). CONCLUSIONS: The source of evidence for prescribing blue-blocking lenses for our participants was mainly from advertisements rather than from scientific studies. Factors such as awareness, knowledge, education, and nature of practice did not play a significant role in prescribing blue-blocking lenses. This raises the need for evidence-based practice and the development of practice guidelines for prescribing blue-blocking lenses.

Does the sampling frequency of an eye tracker affect the detection of glaucomatous visual field loss?

PURPOSE: Evidence suggests that eye movements have potential as a tool for detecting glaucomatous visual field defects. This study evaluated the influence of sampling frequency on eye movement parameters in detecting glaucomatous visual field defects during a free-viewing task. METHODS: We investigated eye movements in two sets of experiments: (a) young adults with and without simulated visual field defects and (b) glaucoma patients and age-matched controls. In Experiment 1, we recruited 30 healthy volunteers. Among these, 10 performed the task with a gaze-contingent superior arcuate (SARC) scotoma, 10 performed the task with a gaze-contingent biarcuate (BARC) scotoma and 10 performed the task without a simulated scotoma (NoSim). The experimental task involved participants freely exploring 100 images, each for 4 s. Eye movements were recorded using the LiveTrack Lightning eye-tracker (500 Hz). In Experiment 2, we recruited 20 glaucoma patients and 16 age-matched controls. All participants underwent similar experimental tasks as in Experiment 1, except only 37 images were shown for exploration. To analyse the effect of sampling frequency, data were downsampled to 250, 120 and 60 Hz. Eye movement parameters, such as the number of fixations, fixation duration, saccadic amplitude and bivariate contour ellipse area (BCEA), were computed across various sampling frequencies. RESULTS: Two-way ANOVA revealed no significant effects of sampling frequency on fixation duration (simulation, p = 0.37; glaucoma patients, p = 0.95) and BCEA (simulation, p = 0.84; glaucoma patients: p = 0.91). BCEA showed good distinguishability in differentiating groups across different sampling frequencies, whereas fixation duration failed to distinguish between glaucoma patients and controls. Number of fixations and saccade amplitude showed variations with sampling frequency in both simulations and glaucoma patients. CONCLUSION: In both simulations and glaucoma patients, BCEA consistently differentiated them from controls across various sampling frequencies.

Tablet-based 'ON/OFF' pathway test can distinguish between rod- and cone-dominated diseases.

INTRODUCTION: The photopic ON pathway defect is associated with nocturnal vision loss. However, the measurement of ON function to detect a rod-dominated disease (rods affected more than cones) has not been explored. We evaluated whether the psychophysical evaluation of ON/OFF pathways can be used to distinguish cone-dominated from rod-dominated diseases. METHODS: Thirty-seven patients with inherited retinal diseases were tested using the 'EyeSpeed' [iOS application] on an iPad. The test displayed a random number (1-3) of light or dark targets on a black-and-white noise background. Participants responded on a touch screen indicating the correct number of targets displayed. The outcome variables-reaction time, accuracy and performance index (speed [1/reaction time] * accuracy) to both light and dark targets were assessed for diagnostic ability using standard receiver-operating characteristic (ROC) analysis. RESULTS: Mean ± standard deviation age and visual acuity for the cone- and rod-dominated groups were 25.15 ± 11.74 years, 0.80 ± 0.25 logMAR and 28.3 ± 14.29 years, 0.48 ± 0.26 logMAR, respectively. The median reaction time to light targets in rod-dominated disease [interquartile range] was 5.28 s [3.17], significantly greater than for patients with cone-dominated disease (2.07 s [0.93]; Mann-Whitney U test, p < 0.001). Amongst all of the outcome variables evaluated, the reaction time to light targets (criterion of ≥2.98 s) exhibited the highest area under the ROC curve (area = 0.89 ± 0.11; p < 0.001), with a sensitivity and specificity of 82.4% and 85% respectively. CONCLUSIONS: Reaction time to light targets using the ON/OFF pathway paradigm is a valid marker to differentiate between rod- and cone-dominated retinal dystrophies. ON pathway function measured using a tablet-based test could act as a supplemental test in the diagnosis of challenging photoreceptor-specific inherited retinal diseases.

Extent of foveal fixation with eye rotation in emmetropes and myopes

Purpose: This pilot study aimed to investigate the maximum extension of foveal fixation in the horizontal direction among young adults in both emmetropes and myopes.Methods35 participants (28 emmetropes and 7 myopes) were included. Participants with restricted extra-ocular mobility, end gaze nystagmus, and/or any other ocular pathology were excluded. Visual acuity (VA) was used as a surrogate measure of foveal fixation. VA was determined using a staircase procedure with 8 reversals. The average of the last 5 reversals was taken as the thresholds. VA acuity was measured at different gaze eccentricities along nasal and temporal visual field meridian. The eccentricity at which VA drops significantly was taken as the maximum extent of foveal fixation. A bilinear fit regression model was used to investigate the drop in the VA in both nasal and the temporal direction.ResultsEmmetropes can foveate up to 35 ± 2° in nasal and 40 ± 3° in temporal direction and myopes can foveate up to 38° in both nasal and temporal directions. Paired student t-test showed a significant difference in foveal fixation between nasal and temporal direction for emmetropes (P<0.001) but not in myopes (P = 0.168). An unpaired student t-test showed a significant difference in foveal fixation for nasal direction between myopes and emmetropes (P = 0.01). However, no statistically significant difference was found in foveal fixation for temporal direction between myopes and emmetropes (P = 0.792).ConclusionThe eye rotation does not necessarily match with the extent of foveal fixation at extreme eye rotation. Eyes can fixate only up to 35° nasally and 40° temporally maintaing their maximum visual acuity. (AU)

Role of microperimetry in evaluating disease progression in age-related macular degeneration: a scoping review.

PURPOSE: Recent research has found variable evidence on the role of mesopic and dark-adapted scotopic microperimetry assessment in age-related macular degeneration. This scoping review summarises how mesopic and scotopic microperimetry can be used to assess disease progression in age-related macular degeneration and identifies gaps in the literature. METHODS: A population, concept, and context approach was used to develop the search strategy. Ovid MEDLINE, EMBASE, Cochrane Library, PubMed, CINAHL Plus, Web of Science, and SCOPUS databases were used to conduct the literature search. The key search terms used in the databases were age-related macular degeneration and microperimetry. RESULTS: Twelve studies were eligible and included in the review. All the studies (n = 12) were conducted in European countries [Germany (9), Italy (2), and the United Kingdom (1)]. The mesopic and scotopic sensitivities were measured using the Nidek scotopic microperimeter (MP1-S) (n = 6), scotopic Macular Integrity Assessment device (S-MAIA) (n = 5), and both MP1-s and S MAIA (n = 1). 83.3% (n = 10) studied (cross-sectional design) on mesopic, scotopic microperimetry and found reduced rod (scotopic) photoreceptors sensitivities compared to cone (mesopic) photoreceptors sensitivities in patients with small and reticular pseudodrusen despite having good visual acuity. Only 16.7% (n = 2) of studies followed participants with reticular drusen/large drusen for three years (longitudinal design) and found reduced scotopic over mesopic sensitivity at baseline and localized mesopic with profound scotopic sensitivity loss during follow-ups. CONCLUSION: Scotopic sensitivity is a better functional indicator than mesopic sensitivity to understand early and intermediate age-related macular degeneration progression. The evidence from longitudinal studies is debatable due to the limited stimuli range of existing microperimeters, smaller sample size, and lost follow-ups.

Extent of foveal fixation with eye rotation in emmetropes and myopes.

PURPOSE: This pilot study aimed to investigate the maximum extension of foveal fixation in the horizontal direction among young adults in both emmetropes and myopes. METHODS: 35 participants (28 emmetropes and 7 myopes) were included. Participants with restricted extra-ocular mobility, end gaze nystagmus, and/or any other ocular pathology were excluded. Visual acuity (VA) was used as a surrogate measure of foveal fixation. VA was determined using a staircase procedure with 8 reversals. The average of the last 5 reversals was taken as the thresholds. VA acuity was measured at different gaze eccentricities along nasal and temporal visual field meridian. The eccentricity at which VA drops significantly was taken as the maximum extent of foveal fixation. A bilinear fit regression model was used to investigate the drop in the VA in both nasal and the temporal direction. RESULTS: Emmetropes can foveate up to 35 ± 2° in nasal and 40 ± 3° in temporal direction and myopes can foveate up to 38° in both nasal and temporal directions. Paired student t-test showed a significant difference in foveal fixation between nasal and temporal direction for emmetropes (P<0.001) but not in myopes (P = 0.168). An unpaired student t-test showed a significant difference in foveal fixation for nasal direction between myopes and emmetropes (P = 0.01). However, no statistically significant difference was found in foveal fixation for temporal direction between myopes and emmetropes (P = 0.792). CONCLUSION: The eye rotation does not necessarily match with the extent of foveal fixation at extreme eye rotation. Eyes can fixate only up to 35° nasally and 40° temporally maintaing their maximum visual acuity.

Comparison of Saccadic Eye Movements Among the High-tension Glaucoma, Primary Angle-closure Glaucoma, and Normal-tension Glaucoma.

PRCIS: Saccadic eye movements were compared between high-tension glaucoma (HTG), normal-tension glaucoma (NTG), and primary angle-closure glaucoma (PACG). Saccades were differently affected between the subtypes of primary glaucoma. AIM: The aim of the study was to compare saccadic eye movements in eyes with HTG, PACG, and NTG. METHODS: Saccadic eye movements were recorded using the eye tracker Eyelink-1000 in 52 participants: 15 HTG, 14 PACG, 8 NTG, and 15 normal controls. All participants underwent a complete ophthalmic and visual field examination. Prosaccades were measured using the gap paradigm. Prosaccades were measured at 3 target eccentricities (5-, 7-, and 10-degree eccentricity). All prosaccade targets were projected outside the area of visual field defect. Saccade latency, average and peak velocity, and amplitude difference of the saccades were compared between glaucoma subtypes. RESULTS: The mean±SD age was lesser in controls compared with glaucoma (P=0.02). The mean age in all the glaucoma subtypes was comparable (P=0.92). The average mean deviation in PACG (-16.66±6.69 dB) was worse (P=0.01) than in HTG (-11.56±6.08 dB) and NTG (-9.55±3.96 dB). The latencies were delayed, average and peak velocities were reduced, and saccades were hypometric in glaucoma compared with controls (P<0.01). Between subtypes, the differences in latency (P<0.01), peak velocity (P=0.02), and amplitude (P=0.02) were significant. Saccadic eye movements were significantly different in NTG compared with other glaucoma subtypes (post hoc analysis; latency (HTG vs. NTG; P<0.01, HTG vs. PACG; P=0.01), peak velocity (HTG vs. NTG; P=0.02) and amplitude difference (HTG vs. NTG; P=0.02). CONCLUSIONS: Saccadic eye movement parameters were differently affected among the glaucoma subtypes. Saccadic parameters were more affected in NTG.

Comparison of Visual Field Progression Rates Among the High Tension Glaucoma, Primary Angle Closure Glaucoma, and Normal Tension Glaucoma.

Purpose: To compare the visual field (VF) progression among high tension glaucoma (HTG), primary angle closure glaucoma (PACG), and normal tension glaucoma (NTG) subjects in routine clinical care. Methods: All patients had ≥5 VF tests using HFA, 24-2, SITA-standard strategy. We compared the progression between glaucoma subtypes after matching the VFs for baseline severity (mean deviation [MD]) and the age at presentation. Global VF progression was evaluated by linear regression analysis (LRA) of MD. For local VF progression, scotoma expansion (SE) defined as appearance of new scotoma and scotoma deepening (SD) defined by pointwise LRA were calculated. SE and SD were analyzed in three VF zones: superior arcuate (SA), inferior arcuate (IA), and central (C). Results: A total of 310 HTG, 304 PACG, and 165 NTG eyes were included. When VFs were matched by baseline MD, a greater number (n = 20/76) of eyes with HTG showed significant progression compared to PACG (n = 9/76; P = 0.04). The number of progressing eyes were not significantly different between HTG and NTG (n = 11/76; P = 0.10) and between NTG and PACG (P = 0.65). When the baseline VFs were matched by age, the number of eyes showing significant progression were similar in all the subtypes. SA zone in HTG and NTG showed greater SE and SD compared to other zones (P < 0.05), whereas IA zone in PACG showed greater SE and SD compared to other zones (P < 0.05). Conclusions: In our cohort of treated primary glaucoma with matched baseline severity, a greater proportion of HTG eyes progressed faster compared to PACG. SA zone in HTG and NTG and IA zone in PACG showed greater VF progression.

Sampling the Visual Field Based on Individual Retinal Nerve Fiber Layer Thickness Profile.

Purpose: Current perimeters use fixed grid patterns. We test whether a grid based on an individual's retinal nerve fiber layer (RNFL) thickness profile would find more visual field (VF) defects. Methods: We describe the defect-based method for choosing test locations. First, the 26 VF locations with the highest positive predictive value to detect glaucoma from the 24-2 pattern are chosen. An additional 26 locations are chosen from a 2 × 2 degree grid based on RNFL thickness. An individualized map was used to relate VF locations to peripapillary RNFL thickness. To test whether the 52 locations chosen by the defect-based method find more defects than other test grids, we collected a 386-location (2 × 2 degree grid) VF measurement on 23 glaucoma participants and classed each location in the dataset as either abnormal or normal using a suprathreshold test. Using this data, defect-based sampling was compared to: a method that sampled VF locations uniformly around the optic nerve head (ONH); the 24-2 pattern; a polar pattern; and a reduced polar pattern. The outcome measure was the number of abnormal points that were selected as test locations. Results: For 8 eyes, no method found more abnormal points than would be expected by chance (hypergeometric distribution, P < 0.05). Of the remaining 15 eyes, the defect-based method identified more abnormal locations on nine eyes, which was significantly better than the other three sampling schemes (24-2: 2 eyes, P < 0.001; polar: 2 eyes, P < 0.001; reduced polar: 2 eyes, P < 0.004; and uniform: 1 eye, P < 0.001). Conclusions: Using structural information to choose locations to test in a VF for individual patients identifies more abnormal locations than using existing grid patterns and uniform sampling based on structure.

Enhancing Structure-Function Correlations in Glaucoma with Customized Spatial Mapping.

PURPOSE: To determine whether the structure-function relationship in glaucoma can be strengthened by using more precise structural and functional measurements combined with individualized structure-function maps and custom sector selection on the optic nerve head (ONH). DESIGN: Cross-sectional study. PARTICIPANTS: One eye of each of 23 participants with glaucoma. METHODS: Participants were tested twice. Visual fields were collected on a high-resolution 3° × 3° grid (164 locations) using a Zippy Estimation by Sequential Testing test procedure with uniform prior probability to improve the accuracy and precision of scotoma characterization relative to standard methods. Retinal nerve fiber layer (RNFL) thickness was measured using spectral-domain optical coherence tomography (OCT; 4 scans, 2 per visit) with manual removal of blood vessels. Individualized maps, based on biometric data, were used. To customize the areas of the ONH and visual field to correlate, we chose a 30° sector centered on the largest defect shown by OCT and chose visual field locations using the individualized maps. Baseline structure-function correlations were calculated between 24-2 locations (n = 52) of the first tested visual field and RNFL thickness from 1 OCT scan, using the sectors of the Garway-Heath map. We added additional data (averaged visual field and OCT, additional 106 visual field locations and OCT without blood vessels, individualized map, and customized sector) and recomputed the correlations. MAIN OUTCOME MEASURES: Spearman correlation between structure and function. RESULTS: The highest baseline correlation was 0.52 (95% confidence interval [CI], 0.13-0.78) in the superior temporal ONH sector. Improved measurements increased the correlation marginally to 0.58 (95% CI, 0.21-0.81). Applying the individualized map to the large, predefined ONH sectors did not improve the correlation; however, using the individualized map with the single 30° ONH sector resulted in a large increase in correlation to 0.77 (95% CI, 0.47-0.92). CONCLUSIONS: Using more precise visual field and OCT measurements did not improve structure-function correlation in our cohort, but customizing the ONH sector and its associated visual field points substantially improved correlation. We suggest using customized ONH sectors mapped to individually relevant visual field locations to unmask localized structural and functional loss.