Quantification of Pupillary Dynamics and Accommodative Response in Adie’s Tonic Pupil: A Case Report

Background: Objective quantification of pupillary dynamics in a clinical setting is of worth importance to rule out any pupillary abnormalities. However, despite normal binocular vision findings, a quantitative measurement of pupillary response and accommodation provides a better insight to understand the mechanism. Case Report: This case report illustrates the clinical presentation, binocular vision parameters, Pupillary dynamics and accommodative response in a 33-year-old diagnosed with Adie’s Tonic pupil following trauma. Conclusion: This report explains the role of the pupillometer and open field autorefractor in quantitative analysis of pupillary and accommodative function.

Theta Burst Stimulation in Adults with Symmetric and Asymmetric Visual Acuity

Purpose: Theta Burst Stimulation can influence adult neuro-visual response in imbalanced visual pathways, possibly by influencing cortical excitability. Our objective was to compare suppressive imbalance (SI) and visual acuity (VA) after applying repetitive Transcranial Magnetic Stimulation (TMS) between groups of subjects with normal binocular vision, visual asymmetry and amblyopia. Methods: Thirty – five volunteers between 19 and 51 years of age, were split into three groups: 6 volunteers with asymmetric VA (group A); 19 amblyopes (group B); and 10 subjects with normal binocular vision (group C). VA and SI of all groups were evaluated before and after a single session of continuous theta-burst stimulation (cTBS) or placebo stimulation over the right occipital cortex. Results: In both groups A and B we found a significant VA improvement in the non-dominant eye after cTBS (p=0.04 and p=0.01, respectively). In SI evaluation, group A and group B also revealed a significant improvement after the cTBS session (p=0.03 and p=0.01, respectively).Finally, in the group of volunteers with normal binocular vision and for placebo groups A and B, there were no significant differences in VA and SI after cTBS. Conclusions: Amblyopic and visually asymmetric individuals improved VA and SI of the non-dominant eye after cTBS when compared to baseline and to placebo stimulation. These enhancements were not found in the group of volunteers with normal binocular vision. We can therefore reasonably assume that cTBS may interfere with the visual system of subjects that present some kind of asymmetry, possibly by improving neuronal imbalances.

Effect of corneal refractive surgery on accommodative and binocular dysfunctions among civilian pilots in Southwest China

Background To analyze whether corneal refractive surgery (CRS) is associated with the distribution of different accommodative dysfunctions (ADs) and binocular dysfunctions (BDs) in civilian pilots. A further aim was to analyze the percentages and visual symptoms associated with ADs and/or BDs in this population. Methods One hundred and eight civilian pilots who underwent CRS from January 2001 to July 2012 (age: 30.33 ± 4.60 years) were enrolled, the mean preoperative SE was − 1.51 ± 1.15 D (range: − 1.00- − 5.00 D). Ninety-nine emmetropic civilian pilots (age: 29.64 ± 3.77 years) who were age- and sex-matched to the CRS group were also enrolled. Refractive status, accommodative and binocular tests of each subject were performed. Visually related symptoms were quantified using the 19-item College of Optometrists in Vision Development Quality of Life (COVD-QOL) questionnaire. The 19 items were summed to obtain visual symptom scores that might indicate visual dysfunctions. The chi-square test was used to analyze differences in percentages of ADs and/or BDs between the CRS and emmetropic groups. The Mann-Whitney U test was used to compare visual symptom scores between pilots with ADs and/or BDs and pilots with normal binocular vision. Results No significant difference was observed between the CRS and emmetropic groups in the overall prevalence of ADs and BDs (15.7% and 15.2% in the CRS and emmetropic groups, respectively; P = 0.185). ADs were present in 4.63% and 3.03% of the CRS and emmetropic group, respectively. BDs were observed in 11.1% and 12.1% of the CRS and emmetropic group, respectively, yielding no significant differences between the groups in the prevalence of ADs or BDs (AD: P = 0.094; BD: P = 0.105). Pilots with ADs and/or BDs had significantly more visual symptoms than pilots with normal binocular vision (p < 0.001). Conclusions CRS for civilian pilots with low-moderate myopia might not impact binocular functions. ADs and/or BDs commonly occur in both emmetropia pilots and pilots who undergo CRS, and pilots with ADs and/or BDs are associated with increased symptoms. This study confirms the importance of a full assessment of binocular visual functions in detecting and remedying these dysfunctions in this specific population.

Effect of corneal refractive surgery on accommodative and binocular dysfunctions among civilian pilots in Southwest China

Background: To analyze whether corneal refractive surgery (CRS) is associated with the distribution of different accommodative dysfunctions (ADs) and binocular dysfunctions (BDs) in civilian pilots. A further aim was to analyze the percentages and visual symptoms associated with ADs and/or BDs in this population.Methods: One hundred and eight civilian pilots who underwent CRS from January 2001 to July 2012 (age: 30.33±4.60 years) were enrolled, the mean preoperative SE was −1.51±1.15 D (range: −1.00- −5.00 D). Ninety-nine emmetropic civilian pilots (age: 29.64±3.77 years) who were age- and sex-matched to the CRS group were also enrolled. Refractive status, accommodative and binocular tests of each subject were performed. Visually related symptoms were quantified using the 19-item College of Optometrists in Vision Development Quality of Life (COVD-QOL) questionnaire. The 19 items were summed to obtain visual symptom scores that might indicate visual dysfunctions. The chi-square test was used to analyze differences in percentages of ADs and/or BDs between the CRS and emmetropic groups. The Mann-Whitney U test was used to compare visual symptom scores between pilots with ADs and/or BDs and pilots with normal binocular vision.Results: No significant difference was observed between the CRS and emmetropic groups in the overall prevalence of ADs and BDs (15.7% and 15.2% in the CRS and emmetropic groups, respectively; P=0.185). ADs were present in 4.63% and 3.03% of the CRS and emmetropic group, respectively. BDs were observed in 11.1% and 12.1% of the CRS and emmetropic group, respectively, yielding no significant differences between the groups in the prevalence of ADs or BDs (AD: P=0.094; BD: P=0.105). Pilots with ADs and/or BDs had significantly more visual symptoms than pilots with normal binocular vision (p < 0.001). Conclusions: CRS for civilian pilots with low-moderate myopia might not impact binocular functions. ADs and/or BDs commonly occur in both emmetropia pilots and pilots who undergo CRS, and pilots with ADs and/or BDs are associated with increased symptoms. This study confirms the importance of a full assessment of binocular visual functions in detecting and remedying these dysfunctions in this specific population.

Effect of Corneal Refractive Surgery on Accommodative and Binocular Dysfunctions Among Civilian Pilots in Southwest China

Background: To analyze whether corneal refractive surgery (CRS) is associated with the distribution of different accommodative dysfunctions (ADs) and binocular dysfunctions (BDs) in civilian pilots. A further aim was to analyze the percentages and visual symptoms associated with ADs and/or BDs in this population.Methods: One hundred and eight civilian pilots who underwent CRS from January 2001 to July 2012 (age range: 23-35 years) and 99 emmetropic civilian pilots (age range: 23-35 years) were included in this study. Visual symptoms, refractive status, accommodative and binocular tests of each subject were performed.Results: No significant difference was observed between the CRS and emmetropic groups in the overall prevalence of ADs and BDs (15.7% and 15.2% in the CRS and emmetropic groups, respectively; P=0.185). ADs were present in 4.63% and 3.03% of the CRS and emmetropic group, respectively. BDs were observed in 11.1% and 12.1% of the CRS and emmetropic group, respectively, yielding no significant differences between the groups in the prevalence of ADs or BDs (AD: P=0.094; BD: P=0.105). Pilots with ADs and/or BDs had significantly more visual symptoms than pilots with normal binocular vision (p < 0.001). Conclusions: CRS for civilian pilots with low-moderate myopia might not impact binocular functions. ADs and/or BDs commonly occur in both emmetropia pilots and pilots who undergo CRS, and pilots with ADs and/or BDs are associated with increased symptoms. This study confirms the importance of a full assessment of binocular visual functions in detecting and remedying these dysfunctions in this specific population.Trial registration number: ChiCTR1900027235 (date: 6 Nov 2019) Available at www.medresman.org

Deficient stereopsis in the normal population revisited: why current clinical stereo tests may not be adequate

Significance statementApplied applications for occupational screening, clinical tests should assess sensitivity to the sign as well as the magnitude of disparity.PurposeTo determine why the high incidence of stereo anomaly found using laboratory tests with polarity-based increment judgements (i.e., depth sign) is not reflected in clinical measurements that involve single-polarity incremental judgements (i.e., depth magnitude).MethodsAn iPod-based measurement that involved the detection of an oriented shape defined by a single polarity-depth increment within a random dot display was used. A staircase procedure was used to gather sufficient trials to derive a meaningful measure of variance for the measurement of stereopsis over a large disparity range. Forty-five adults with normal binocular vision (20 - 65 years old) and normal or corrected-to-normal (0 logMAR or better) monocular vision participated in this study.ResultsObservers’ stereo acuities ranged between 10 and 100 arc seconds, and were normally distributed on a log scale (p = 0.90, 2-tailed Shapiro-Wilk test). The present results using a single polarity depth increment task (i.e., depth magnitude) show a similar distribution to those using a similar task using the Randot preschool stereo test on individuals between the ages of 19-35 using either the 4-book test (n = 33) or the 3-book test (n = 40), but very different results when the iPod test involved a polarity-based increment judgement (i.e., depth sign).ConclusionsThe present clinical stereo tests are based on magnitude judgements and are unable to detect the high percentage of stereo anomalous individuals in the normal population revealed using depth sign judgements.

Quantitative Approach for the Analysis of Fusional Convergence Using Eye-Tracking and SacLab Toolbox

Fusional vergence is a disjunctive movement of the eyes that is made in order to obtain single vision. The aim of the study was to provide a quantitative and objective approach for analyzing the fusional convergence response using eye tracking (ET) technology and automatic data analysis provided by the intuitive SacLab toolbox previously developed by our group. We evaluated the proposed approach in a population of 26 subjects with normal binocular vision, who were tested with base-out prisms (magnitudes 4Δ, 6Δ, and 10Δ) in order to elicit fusional convergence response. Eye movements were recorded using the Viewpoint ET and analyzed using SacLab. Parameters describing both the vergence and the version components of the fusional response (convergence duration, CD; peak convergence velocity, PCV; number of intrusive saccades, NS; and mean saccadic amplitude, MSA) were automatically calculated and provided to clinicians for an objective evaluation. Results showed that the number of subjects achieving fusional convergence decreased with prism magnitude. For subjects achieving fusion CD and PCV increased significantly (p<0.05) when increasing the prism magnitude. For NS and MSA, there were no significant changes when passing to 6Δ, but a significant increase resulted when passing to 10Δ (p<0.05). Noninvasive ET associated with the intuitive SacLab toolbox may represent a valid option to objectively characterize the fusional vergence response in clinical setting. The analysis may be extended to patients with vergence disorders.

Hoya Eyegenius®: New Method for Measuring and Correcting Fixation Disparity

Many things interfere with good binocular vision in nowadays modern digital environment: long periods spent looking at screens and switching between different digital devices at short distances. Vision-related or asthenopic complaints such as headaches, tired and burning eyes or blurred vision can be experienced by many people. Prescribing prismatic correction for fixation disparity can help to reduce these symptoms. A new, highly innovative method for measuring and correcting fixation disparity has been developed - HOYA EyeGenius®. The HOYA EyeGenius® method includes the unique examination procedures, pre-tests and fixation disparity measurements at far and near distances. The pre-tests allow to include patients with asthenopic complaints only with normal binocular vision and exclude cases with abnormal binocular vision. The main innovation of EyeGenius is based on direct conversion of the fixation disparity value into a prism amount. Therefore, the trial prismatic lenses are not used during the test. The use of digital devices makes this method interactive and minimizes the influence of the examiner.