Binocular Visual Function Research Articles

Visual Skills and Reading Ability: Role of Functional Binocular Vision (FBV)

Visual Skills and Reading Ability: Role of Functional Binocular Vision (FBV)

Visual Function of Drivers and its Relation to the Occurrence of Road Traffic Accidents in Saudi Arabia

BACKGROUND: The mortality rate due to road traffic accidents (RTA) is significantly high in Saudi Arabia (SA) compared to other countries. The visual function which includes good visual acuity (VA) and binocular vision are very important factors that can contribute to the incidence of RTA. AIM: The aim of this study is to investigate the association between refractive errors (REs) and the RTA in SA. METHODS: A total of 354 participants (mean age 22.67 ± 3.22 years) were recruited randomly to participate in this study from the population of Qassim district. Data collected using the questionnaire included participants’ age, sex, and education level, ocular and medical history, driving history as well as history of RTA. Ocular health examination including VA, RE measurements, and binocular vision function vision was measured and analyzed. RESULTS: The results of this study show that 48.3% of drivers had some form of REs with 3.4% being visually impaired. 217 (61.3%) of participants have had an RTA, and 119 (54.9%) of them have had more than two accidents in the past two years. The findings show no significant association between the occurrence of RTA and uncorrected REs or binocular vision dysfunction. CONCLUSION: Our data showed significantly higher rate of RTA among Saudi drivers which is much higher than any country in the world. The current Saudi regulations for obtaining driving license need to be modified, with implementing a comprehensive eye examination prior to acquiring or renewing drivers’ licenses.

Binocular Interactions in Glaucoma Patients With Nonoverlapping Visual Field Defects: Contrast Summation, Rivalry, and Phase Combination.

PurposeIn glaucoma, visual field defects in the left and right eye may be non-overlapping, resulting in an intact binocular visual field. In clinical management, these patients are often considered to have normal vision. However, visual performance also relies on binocular processing. The aim of this study was to evaluate binocular visual functions in glaucoma patients with intact binocular visual field, normal visual acuity, and stereoscopy.MethodsWe measured in 10 glaucoma patients and 12 age-similar controls: (1) monocular and binocular contrast sensitivity functions (CSF) using a modified quick CSF test to assess binocular contrast summation, (2) dominance during rivalry, and (3) contrast ratio at balance point with a binocular phase combination test. A mirror stereoscope was used to combine the left and right eye image (each 10° horizontally by 12° vertically) on a display.ResultsArea under the monocular and binocular CSF was lower in glaucoma compared to healthy (P < 0.001), but the binocular contrast summation ratio did not differ (P = 0.30). For rivalry, the percentage of time of mixed percept was 9% versus 18% (P = 0.056), the absolute difference of the percentage of time of dominance between the two eyes 19% versus 10% (P = 0.075), and the rivalry rate 8.2 versus 12.1 switches per minute (P = 0.017) for glaucoma and healthy, respectively. Median contrast ratio at balance point was 0.66 in glaucoma and 1.03 in controls (P = 0.011).ConclusionsBinocular visual information processing deficits can be found in glaucoma patients with intact binocular visual field, normal visual acuity, and stereoscopy.

A Study to Assess the Feasibility of Utilising Virtual Reality for the Treatment of Accommodative and Vergence Infacility

Background:To assess the feasibility, as well as viability, of utilising gaming using virtual reality (VR) to treat accommodative and vergence infacilities.Methods:Forty-two emmetropic and asymptomatic participants between the ages of 18 and 30, with normal binocular visual function, were selected for the study in 2018. Participants with binocular accommodative infacilities and/or vergence infacilities comprised the study population. The binocular accommodative facilities (BAF) were assessed using amplitude-scaled facilities (probe lens = 30% amplitude of accommodation; test distance = 45% amplitude of accommodation). All those with less than 10 cycles per minute (cpm) were regarded as failing. Vergence facilities were assessed using 12 pd base out and 3 pd base in prisms. All those with less than 15 cpm were regarded as failing. The participants were separated into age-matched experimental and control groups. The experimental group played a fast-paced game using Samsung Gear VR (SM-R323), whilst the control group watched a television film projected onto a two-dimensional screen at a distance of one metre. Pre-test and post-test binocular amplitude-scaled facilities and vergence facilities were measured for both groups after exposure for 25 minutes.Results:There was a significant, mean increase in binocular accommodative facilities of 4.67 ± 5.05 cpm (p = 0.008) for the experimental group (n = 12). There was a significant mean increase in vergence facilities of 3.72 ± 3.18 cpm (p < 0.001) for the experimental group (n = 32). A statistically significant mean difference of 4.07 cpm (95%CI: 0.97, 9.19; p = 0.03) between the respective control and experimental groups was found for binocular accommodative facilities and 2.45 cpm (95%CI: 0.68, 4.22; p = 0.008) for vergence facilities.Conclusion:Binocular accommodative facilities and vergence facilities increased after 25 minutes of VR gaming in asymptomatic emmetropic participants with accommodative infacilities and vergence infacilities. However, due to the small-scale, unmasked and unrandomised nature of the study more research is needed to confirm the results of this study.

Longitudinal Rehabilitation of Binocular Function in Adolescent Intermittent Exotropia After Successful Corrective Surgery.

PurposeTo study the longitudinal rehabilitation of binocular visual function in adolescent intermittent exotropia (IXT) after successful surgery and compare the results with those of a normal population. The role of binocular function in ocular alignment stability was also evaluated postoperatively.MethodsIn this prospective study, 30 adolescents with IXT successfully corrected after 1 month were followed for 12 months, and 30 children with normal vision were enrolled as controls. Stereopsis, the fusional vergence amplitude, sensory fusion, and accommodative flexibility were measured to assess binocular function at baseline and 6 and 12 months postoperatively. The controls were tested once when they were enrolled in the study.ResultsThe deviation was −32.00 ± 8.60 prism diopters (PD) at distance fixation and −36.0 ± 9.10 PD at near fixation preoperatively with an average correction of 28.53 ± 3.79 PD and 30.67 ± 1.34 PD at 1 month postoperatively. Distance stereoacuity and near stereoacuity improved from 1 to 12 months postoperatively (p = 0.025 and p = 0.041, respectively). Compared with the controls, the fusional convergence reserve at distance (p = 0.025) and near (p = 0.033) fixations and fusion reserve ratio at distance (p = 0.000) and near (p = 0.000) fixations remained subnormal, whereas sensory fusion (p = 0.237), distance stereopsis (p = 0.120), and the fusional divergence amplitude at a distance (p = 0.168) were normal. However, no significant correlations were found between binocular functions at 1 month postoperatively and the postoperative drift.ConclusionBinocular function significantly improved from before to after successful corrective surgery and continued to improve from 1 to 12 months postoperatively in adolescents with IXT. No significant correlations were found between binocular functions at 1 month postoperatively and ocular alignment stability.

Effect of Undercorrection Using Spectacle Lens and Multifocal Soft Contact Lens on Binocular Visual Function

Purpose : To investigate the effect of undercorrection using multifocal soft contact lens and +1.00 D spectacle lens on binocular visual function compared to no correction. Methods : Seventeen individuals (mean age of 23.58±2.12 years) were recruited to participate in this study. Seventeen participants have less than sphere refractive error of ±1.00 D and with less than –0.75 D of astigmatism. Repeated measurements were performed using three different correction options; no correction (NC), correction using multifocal contact lenses (CM) with a plano power for distance and addition up to +1.00 D and undercorrection using +1.00 D spectacle lens (UL). The battery of binocular visual function measures includes amplitude of accommodation, accommodative response, accommodative facility, amplitude of divergence, convergence facility and near/distance phoria. Results : Types of vision correction had no significant effect on amplitude of accommodation, amplitude of divergence and distant phoria. Accommodative response with no correction was statistically significantly bigger than other two correction options, and CM induced statistically significant accommodative response compared to UL. Also, accommodative facility with no correction and CM were statistically significantly better than accommodative facility of UL. Convergence facility with UL and CM were statistically significantly better than NC. Also, near phoria measured Howell chart with UL and CM were statistically significant than NC whereas near phoria measured with Maddox rod with UL was statistically different from NC. Conclusion : Multifocal contact lens do not alter important changes in accommodative system yet provide better accommodative stimulus-response and vergence response. The subjects with multifocal contact lens exhibited decreased accommodative response and improved convergence facility. Thus, simultaneous image multifocal contact lenses may be useful for children and young adults who presented accommodative problems or vergence disorder.

Призматический этап лечения пациентов при остро приобретенной эзотропии с диплопией

Purpose. To analyze changes in binocular vision functions in patients with acutely acquired esotropia after preoperative correction by prisms. Material and methods. The study included 10 patients with acutely acquired esotropia with diplopia. Depending on the tactics of preoperative case management, two groups were distinguished: 1 - 5 patients, this group underwent preoperative prismatic correction of diplopia and the deviation angle, 2 - 5 patients, in this group underwent surgery without prior prismatic correction. Fresnel prisms were used to select and assign prismatic correction. The patients were monitored dynamically. Results. In the course of treatment 1 group according to the indicator of Worth's four-dot test color test, revealed a statistically significant increase in the frequency of value of the binocular single vision (p=0.041), the frequency of the presence of stereovision according to the Fly-test (p=0.013). Conclusion. Prismatic correction in combination with surgical treatment had better curative benefits than surgery itself in improving binocular and stereoscopic visual functions. Key words: acutely acquired esotropia, binocular vision, Fresnel prisms.

Detection of Static and Dynamic Stereopsis after Femtosecond Laser Small Incision Lenticule Extraction for High Myopia.

Purpose The purpose of this study is to test binocular visual function after femtosecond laser small incision lenticule extraction (SMILE) for high myopia. The traditional Titmus stereotest and dynamic stereotest based on the visual perception biological model were used for comparative analysis. Methods A total of 43 patients were enrolled in this prospective study. At Week 1, Month 1, and Month 3 after surgery, the Titmus stereotest and dynamic stereotest generated by MATLAB were conducted. Dynamic stereopsis consists of randomly flickering Gabor spots and is divided into two models of high energy and low energy according to flicker frequency. Results The preoperative manifest refraction spherical equivalent was −7.21 ± 0.70 D. The preoperative anisometropia was 0.52 ± 0.54D. The quartiles of static stereoacuity in preoperation and 3 follow-ups were as follows: 50.00 (25.00, 100.00) in preoperation, 63.00 (40.00, 63.00) at Week 1, 40.00 (32.00, 63.00) at Month 1, and 40.00 (25.00, 50.00) at Month 3. Static stereopsis improved at Month 1 and Month 3 compared with preoperation and Week 1 (P < 0.05). There were statistically significant differences in high energy dynamic stereopsis at Week 1 and Month 1 compared to preoperation (P < 0.05). In addition, significant differences in low energy dynamic stereopsis were detected between Month 1 and preoperation and also at Month 3 compared to Month 1 (P < 0.05). Conclusion Most high myopia patients have a dynamic stereopsis deficiency before refractive correction. SMILE surgery can improve both static and dynamic stereopsis early in the postoperation period. However, in the long term, there is no significant difference or even a decrease in dynamic stereopsis.

Normative Data for Nonstrabismic Binocular Vision Parameters in African Schoolchildren.

With reported population differences in parameters of nonstrabismic binocular vision, the present study investigated and reports normative data among a sample of African children. This study aimed to determine expected binocular visual function data among schoolchildren in the Central Region of Ghana. The study used a prospective cross-sectional design and used a multistage cluster sampling approach. Eligible normal participants selected through the administration of Convergence Insufficiency Symptom Survey questionnaire (score <16) and preliminary vision screening underwent comprehensive binocular vision testing. Only data for participants who expressed no difficulty with the specific procedures were analyzed. A total of 1261 normal participants (11 to 17 years [mean, 14.75 ± 1.530 years]) were selected for comprehensive binocular vision testing in the normative data study. The means with ±1 standard deviation for normative data for the nonstrabismic binocular vision parameters include the following: accommodative target near point of convergence (NPC) break (6.10 ± 1.67 cm), NPC recovery (8.17 ± 1.67 cm), fixation light with red-green anaglyph (RG NPC) break (8.51 ± 2.43 cm), RG NPC recovery (10.95 ± 2.60 cm), cover test distance phoria (0.12 ± 0.79 exophoria), cover test near phoria (2.1 ± 2.3 exophoria), modified Thorington test near phoria (1.9 ± 2.5 exophoria), negative relative accommodation (+2.54 ± 0.75 D), positive relative accommodation (-2.58 ± 0.81 D), and the accommodative convergence over accommodation ratio (2.80 ± 1.07:1). Age (in years)-predicted normal linear regression equations for NPC break (5.13 + 0.07 × age), RG NPC break (10.00 - 0.10 × age), RG NPC recovery (12.83 - 0.13 × age), positive relative accommodation (2.05 + 0.04 × age), and the gradient accommodative convergence over accommodation ratio (3.97 - 0.08 × age) serve as a guide. The study provides expected data that optometrists may use with similar aged Black African populations.

Deterioration of binocular vision after alcohol intake influences driving performance

In this study, we assessed the influence of moderate alcohol intake on binocular vision, vergence system and simulated driving performance by analyzing the interactions between visual deterioration and driving variables. Thirty young healthy subjects were recruited. For the analysis, we measured: visual function (visual acuity and stereoacuity), phorias and fusional reserves. Also, we checked Sheard’s and Percival’s criteria at near and far. The accommodative convergence/accommodation (AC/A) ratio was calculated and vergence facility was also obtained at near. A driving simulator was used to assess driving performance under natural conditions and after alcohol consumption with a breath alcohol content of 0.40 mg/l. Alcohol intake significantly reduced binocular visual performance and vergence function, except for vertical phorias, horizontal phoria at near and Sheard’s and Percival’s criteria at near. Driving performance parameters also presented a statistically significant deterioration after alcohol consumption. A statistically significant correlation was found between the deterioration in overall visual function and overall driving performance, highlighting the influence of the visual deterioration on the driving performance. Moderate alcohol consumption impairs binocular visual and simulated driving performances, implying a greater safety hazard. In addition, deteriorations in binocular visual function and vergence correlated with simulated driving impairment, which indicates that the deterioration of binocular vision due to alcohol consumption affects driving, thus reducing road safety.

A Randomized Clinical Trial Comparing Eyetronix Flicker Glass and Patching for Treatment of Amblyopia in Children Reveals Similar Improvements in Vision.

PurposeRecently, Eyetronix Flicker Glass (EFG) has been introduced as a novel treatment for amblyopia. It alternatively deprives the visual input of each eye rapidly (e.g., 7 Hz). However, whether it is comparable with standard patching therapy is unclear. In this randomized clinical trial, we evaluate the efficacy of an EFG therapy as treatment for amblyopia in children and compare it to the patching therapy.MethodsWe tested 31 children (aged 4–13 years) with amblyopia. They were assigned into one of the two treatment groups and were treated for 12 weeks. The first group was treated with EFG for 1 h/day (Flicker Group) and the latter with a standard patch (Patching Group) for 2 h/day. We designated changes from baseline in best-corrected visual acuity (BCVA) of the amblyopic eye as our primary outcome. Changes from baseline in other visual outcomes, such as contrast sensitivity, stereopsis, and fusional vergence range were measured as secondary outcome.ResultsBCVA improved significantly at 12 weeks relative to baseline in both the Flicker (0.13 ± 0.11 logMAR; mean ± SD) and Patching Groups (0.21 ± 0.14 logMAR). However, the improvements were not significantly different between groups (p = 0.13). Contrast sensitivity also significantly improved at 3 and 12 cycles/degree between baseline and 12 weeks in both groups (p’s < 0.05). However, stereopsis and fusion range did not improve significantly in both groups.ConclusionAn EFG therapy and patching improved BCVA similarly for children with amblyopia at 12 weeks. Both therapies improved the contrast sensitivity at 3 and 12 cycles per degree (cpd); however, only patching improved the contrast sensitivity at 6 cpd. Both therapies did not benefit binocular visual functions (stereopsis and fusional vergence range). We believe that EFG can be an additional choice for therapy.Clinical Trial Registrationchictr.org number: ChiCTR2000034436.

Topical Review: Assessment of Binocular Sensory Processes in Low Vision.

This article summarizes the evidence for a higher prevalence of binocular vision dysfunctions in individuals with vision impairment. Assessment for and identification of binocular vision dysfunctions can detect individuals experiencing difficulties in activities including reading, object placement tasks, and mobility.Comprehensive vision assessment in low vision populations is necessary to identify the extent of remaining vision and to enable directed rehabilitation efforts. In patients with vision impairment, little attention is typically paid to assessments of binocular vision, including ocular vergence, stereopsis, and binocular summation characteristics. In addition, binocular measurements of threshold automated visual fields are not routinely performed in clinical practice, leading to an incomplete understanding of individuals' binocular visual field and may affect rehabilitation outcomes.First, this review summarizes the prevalence of dysfunctions in ocular vergence, stereopsis, and binocular summation characteristics across a variety of ocular pathologies causing vision impairment. Second, this review examines the links between clinical measurements of binocular visual functions and outcome measures including quality of life and performance in functional tasks. There is an increased prevalence of dysfunctions in ocular alignment, stereopsis, and binocular summation across low vision cohorts compared with those with normal vision. The identification of binocular vision dysfunctions during routine low vision assessments is especially important in patients experiencing difficulties in activities of daily living, including but not limited to reading, object placement tasks, and mobility. However, further research is required to determine whether addressing the identified deficits in binocular vision in low vision rehabilitative efforts directly impacts patient outcomes.

A Multi-Modality Treatment Approach in Vision Therapy for a Patient with Form Deprivation Adult Strabismic Amblyopia and Nystagmus: A Case Report

Background: Amblyopia is characterised by visual impairment along with compromised binocular visual function. Form deprivation amblyopia is a result of opaque media which results in obstruction of light. This obstruction of light prevents visual development. It is has traditionally been managed at early stage of life through occlusion therapy. Case Summary: A 29-year old male presented to us, diagnosed with form deprivation adult strabismic amblyopia and nystagmus. Anterior segment evaluation showed pseudophakia in both eyes, and posterior segment was within normal limits. Stereopsis was absent. In-office vision therapy and homebased vision therapy was undertaken, which included optometric syntonic phototherapy, biofeedback mechanisms to improve nystagmus along with oculomotor skills, monocular fixation in a binocular field (MFBF) and binocular therapies in-office, and Amb-iNet at home. Conclusion: A multi-modality treatment approach in vision therapy is presented, which resulted in improvement of visual acuity, stereopsis and other components of vision for an adult with form deprivation strabismic amblyopia and nystagmus.

Monocular and Binocular Visual Function Deficits in Amblyopic Patients with and without Fusion Maldevelopment Nystagmus.

PurposeThe aim of the study is to examine the association between amblyopia type and the presence of nystagmus on binocular and monocular functions of the fellow (FE) and amblyopic eye (AE).MethodsWe recruited 19 controls and 44 amblyopes (anisometropes=13, strabismic=10, mixed=21). We measured visual, grating, and vernier acuities and high/low spatial frequency (SF) contrast sensitivities in each eye using a staircase method. Stereoacuity was measured with the Titmus fly test. We recorded fixation eye movements (FEM) using high-resolution video-oculography. Subjects were classified as having either no nystagmus (n=18), fusion maldevelopment nystagmus syndrome (FMNS) (n=12), or nystagmus without any structural anomalies that does not meet the criteria for FMNS or infantile nystagmus (n=14).ResultsAnalysis of visual function by clinical amblyopia type showed that patients with strabismus/mixed amblyopia (F (2,54)=9.5, p<0.001) were more likely to have poor stereopsis while controlling for AE grating acuity deficit. The FE of patients with anisometropia had greater contrast sensitivity deficits at low (F (2,43)=4.4, p=0.018) and high SF (F (2,42)=10.1, p<0.001). Analysis of visual function by FEM characteristics (low SF: (F (3,43)=4.3, p=0.010) and high SF: (F (3,42)=7.1, p=0.001) showed that the FE of patients with FMNS had worse low and high SF contrast sensitivities, whereas those without FMNS had greater contrast sensitivity deficits only at high SF compared to controls. Patients with FMNS (F (3,54) = 12.9, p<0.001) were more likely to have poor stereopsis while controlling for AE grating acuity deficit compared to patients without FMNS. All amblyopic patients had worse high SF contrast sensitivity of the AE irrespective of type or FEM characteristics (Type = F (2,43)=8.8, p=0.001; FEM characteristics= F (3,43)=5.1, p=0.004).ConclusionThe presence of FMNS in patients with strabismic/mixed amblyopia is associated with poor/absent stereopsis. FE deficits vary across amblyopia type. Like FEM abnormalities, visual function deficits are seen in the FE of patients with and without nystagmus.

Binocular integration and stereopsis in children with television torticollis

BackgroundTo observe the characteristics of binocular integration and stereopsis in children with television torticollis.MethodsA retrospective study was carried out, where data were collected from 25 children with television torticollis as the disease group after refractive error correction and 25 normal children as the control group. A virtual reality system was used to assess and analyze the characteristics of binocular integration by a contrast balance test and binocular stereopsis.ResultsThe 25 children in the disease group included 17 males and 8 females with an average age of 7.5 ± 1.9 years old and an average binocular spherical equivalent of − 0.35 ± 1.46D. The 25 children in the control group were also 17 males and 8 females with an average age of 7.3 ± 2.2 years old and the average binocular spherical equivalent of − 0.48 ± 0.93D. No significant differences were found in the horizontal bar contrast balance test between the 2 groups at near and far distances. Near-distance vertical bar contrast balance test was normal in 23 subjects and suppressed in 2 subjects in the control group, while it was normal in 13 subjects and suppressed in 12 subjects in the disease group, which showed a statistically significant difference (P = 0.002). Far distance vertical bar contrast balance test was normal in 24 subjects and suppressed in 1 subject in the control group, normal in 7 subjects and suppressed in 18 subjects in the disease group, showing a statistically significant difference (P = 0.000). All subjects in the 2 groups showed 100〞 as near distance stereoacuity. At far distance, the mean stereoacuity was 176.00〞 ± 92.56〞 in the control group, and 352.00〞 ± 270.99〞 in the disease group, with a statistically significant difference (P = 0.011).ConclusionBy using virtual reality technology, defects in binocular visual function were found in children whose television torticollis persisted after regular refractive error correction. Television torticollis may be associated with the deficit of binocular integration for vertical bars and far distance stereopsis.

Yoga Ocular Exercises to Maintain Eye Health During Work and Distance Learning in the New Normal Era

The COVID-19 outbreak is a challenge for the world of work and education to change all activities from face-to-face system into remote system with internet and technology-based online system. These online activities lead to increased exposure from digital screen such as computers and mobile phones in the society. Viewing a computer or digital screen often makes our eyes work harder, this high visual demands of digital screen display makes many people susceptible to the development of vision-related symptoms. This article aims to determine the effect of yoga ocular exercises on eye fatigue and increase eye health The method we used was a literature study that focused on yoga ocular interventions in overcoming eye fatigue with databases in the form of PubMed, Willey, Proquest and, Google Scholar published in 2015-2020. Through a review of 8 selected articles, the results showed that yoga ocular practice provides benefits in the form of reduce eye fatigue, relax the mind, prevent asthenopia symptoms, improve binocular vision function by increasing the efficiency of eye motility muscles, and also reduce the intraocular pressure in glaucoma patients. Through the review, it can be seen that yoga ocular practice can prevent vision problems and maintain eye health in the new normal era

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

BackgroundTo 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.MethodsOne 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.ResultsNo 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).ConclusionsCRS 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.

Microstructural properties of major white matter tracts in constant exotropia before and after strabismus surgery

AimsThe purpose of this study was to explore the microstructural properties of the major white matter (WM) tracts in constant exotropia (XT) before and after strabismus surgery, and further investigate...

Impact of binocular integrated visual field defects on healthy related quality of life in glaucoma.

To investigate the impact of different types of binocular integrated visual field defects on the quality of life in glaucoma.Ninety-six patients with primary glaucoma were divided into 5 groups with 25, 24, 11, 15, and 21 patients according to types of the binocular integrated visual field (BVF) defects. The criteria for BVF grouping included mild visual field defect in binocular eyes, mild visual field defect in 1 eye and moderate or advanced defect in the other, moderate and non-overlapping visual field defect in both eyes, overlapping and moderate visual field defect in binocular eyes, and severe defect in both eyes, respectively. The visual field (VF) evaluation was based on H-P-A visual field grading system. Visual acuity, visual field tests and Glaucoma Quality of Life-15 Questionnaire (GQL-15) were performed for enrolled patients, and binocular visual field results were integrated. The changes and correlations of the Visual field index values and quality of life scores were compared among the 5 groups. The main factors affecting the quality of life in glaucoma were analyzed by multiple regression analysis.The best binocular integrated visual field index (BVFI) and optimal quality of life were observed in group A. The BVFI of group B was better than that of group C or group D, but the peripheral vision glare and dark adaptation were worse. No significant difference was noted between group C and group D in terms of BVFI. However, the glare and dark adaptation in group C were better than that in group D. The BVFI was the lowest and the quality of life was the worst in group E. In all, BVFI and decibels (dB) values were negatively correlated with GQL-15 scores and positively correlated with patients’ quality of life.Binocular integrated visual field accurately reflects the visual function in glaucoma. Higher binocular integrated visual field indices represent a better quality of life for patients with glaucoma. Mild to moderate synchronous or complementary binocular VF defects had a slight effect on the quality of life, while severe and non-compensated VF loss significantly impacts on quality of life in glaucoma patients.

A device for evaluation of binocular visual function: a binocular open-view wavefront sensor

A device for evaluation of binocular visual function: a binocular open-view wavefront sensor