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Background: Active vision therapy for amblyopia shows good results, but there is no standard vision therapy protocol. This study compared the results of three treatments, two combining patching with active therapy and one with patching alone, in a sample of children with amblyopia. Methods: Two protocols have been developed: (a) perceptual learning with a computer game designed to favour the medium‐to‐high spatial frequency‐tuned achromatic mechanisms of parvocellular origin and (b) vision therapy with a specific protocol and 2‐h patching. The third treatment group used patching only. Fifty‐two amblyopic children (aged 4–12 years), were randomly assigned to three monocular treatment groups: 2‐h patching (n = 18), monocular perceptual learning (n = 17) and 2‐h patching plus vision therapy (n = 17). Visual outcomes were analysed after 3 months and compared with a control group (n = 36) of subjects with normal vision. Results: Visual acuity (VA) and stereoacuity (STA) improved significantly after treatment for the three groups with the best results for patching plus vision therapy, followed by monocular perceptual learning, with patching only least effective. Change in the interocular difference in VA was significant for monocular perceptual learning, followed by patching. Differences in STA between groups were not significant. For VA and interocular differences, the final outcomes were influenced by the baseline VA and interocular difference, respectively, with greater improvements in subjects with poorer initial values. Conclusions: Visual acuity and STA improved with the two most active treatments, that is, vision therapy followed by perceptual learning. Patching alone showed the worst outcome. These results suggest that vision therapy should include monocular accommodative exercises, ocular motility and central fixation exercises where the fovea is more active. [ABSTRACT FROM AUTHOR]

Introduction: There remains a lack of compelling objective evidence on whether stereopsis is necessary for an ophthalmic surgical career. It is also unclear if high-grade stereoacuity correlates with better surgical performance. The present study attempts to address this question by comparing the simulated surgical performance of subjects with different levels of stereoacuity using a virtual reality (VR) intraocular surgical simulator (EYESi, VRmagic, Mannheim, Germany). Methods: Subjects were tested based on their stereoacuity level and stratified in three age-matched groups: normal stereopsis, subnormal stereopsis, and patients with no measurable stereoacuity in the clinical setting. Eleven subjects in each group to make a total of 33 subjects with no prior surgical experience were recruited from the IWK Health Centre, Halifax, Canada (REB trial registration: 1023183). Subjects performed three attempts on a standardized microsurgical module on the EYESi VR simulator. Results: There was no significant main effect of the stereo-group that the participants belonged to on their total scores, or on the time needed to complete the task, or on the odometer value, or on the amount of injury to surrounding tissues. Discussion: This study showed that for a basic simulated microsurgical task on the EYESI intraocular surgical simulator, the performance of individuals with reduced and absent stereoacuity was statistically indistinguishable from those with normal stereoacuity. Therefore, caution is still recommended when advocating for mandatory high level of stereoacuity as a requirement for admission to training programs in ophthalmology. There is still definite need for solid evidence that stereopsis is necessary to achieve satisfactory skills in ophthalmic microsurgery. [ABSTRACT FROM AUTHOR]

Teiji Yagasaki,1,2 Yoshimi Yokoyama,2 Ayaka Yagasaki,1,2 Kenta Hozumi,2 Sho Ichikawa2,3 1Yagasaki Eye Clinic, Ichinomiya, Aichi, Japan; 2Department of Ophthalmology, Japan Community Health Care Organization Chukyo Hospital, Nagoya, Aichi, Japan; 3Chukyo Eye Clinic, Nagoya, Aichi, JapanCorrespondence: Teiji Yagasaki, Email y-teiji@jb3.so-net.ne.jpPurpose: Favorable stereoacuity does not develop in all patients with partially refractive accommodative esotropia (PRAET) successfully aligned, and there have been few previous reports on the factors influencing stereoacuity outcomes in patients with PRAET treated with prismatic correction (PPC) and/or surgery. This study aimed to analyze factors affecting stereoacuity outcomes in patients of PRAET treated with PPC and surgery.Study Design: Retrospective study.Methods: Sixty-six patients with alignment within 10 prism diopters at final visit with PPC and surgery were included. According to the final stereoacuity, patients were grouped into the fine group (≤ 60 arcsec (“)), the coarse group (60 “ 6 months, ≤ 2 years; late: > 2 years) was carried out with the Kruskal–Wallis test.Results: There were no differences in ages at initial PPC, at surgery, at final visit, durations of misalignment, of PPC, or after surgery; however, significant differences in ages at onset and initial visit were found. Age at onset in the absent group was significantly earlier than those of the fine and the coarse groups (p < 0.001 and p < 0.001, respectively). Moreover, of the 25 patients with age at onset > 2 years, 18 patients (72%) showed fine or coarse stereoacuity (p < 0.001).Conclusion: Although stereoacuity outcomes in patients with early onset were poor despite of the finally successful alignments obtained with PPC and surgery, fine stereoacuity and coarse stereoacuity were obtained in 24% and 44% of patients with age at onset > 2 years.Keywords: partially refractive accommodative esotropia, prism correction, stereoacuity, critical period, surgery

Purpose: We aimed to evaluate distance stereoacuity (DS) in patients with successfully treated accommodative esotropia (AET) and its association with other clinical factors. Methods: The medical records of 176 children with refractive AET with a follow-up period ≥ 1 year were reviewed to identify a cohort of patients who achieved a stable alignment within 4 prism diopters (PD) of orthotropia at both distance and near fixation. Age of onset, duration of misalignment, uncorrected near and distance deviation, accommodative convergence/accommodation ratio, refractive error, presence of anisometropia and amblyopia, near stereopsis were evaluated as predictors of outcome. DS was measured using the Distance Randot Stereo test and near stereoacuity by Randot Stereotest. The patient group was compared with 50 age-matched normal controls for DS. Results: Fifty-six patients were included, and 38 patients had DS at the final visit. All patients with DS attained uncontoured near stereopsis (UCNS). UCNS was present only in 11 patients without DS (p = 0.001). Anisometropia (p = 0.997), uncorrected near deviation (p = 0.224), distance deviation with correction (p = 0.255), and high hypermetropia (p = 0.998) were not associated with DS. The multivariable regression model showed a significant positive correlation between UCNS and DS (OR = 31.14 (95% CI 2.25–430.48); p = 0.01). Contoured near stereopsis outcome was significantly different between the patients with and without DS (p = 0.001 for animals and p = 0.003 for circles). Compared with the control group, the patient group yielded lower DS scores (p = 0.001). Conclusion: Distance Randot Stereotest can be useful in measuring binocular vision recovery after successful realignment in refractive AET patients. Patients attaining normal scores for near stereopsis tests after optical correction revealed subnormal thresholds for DS. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate stereopsis in term-born, preterm, and preterm children with and without retinopathy of prematurity (ROP) and its treatment. Methods: The cross-sectional study included 322 children between 3 and 11 years of age born term or preterm, with or without ROP, and with or without treatment for ROP. The ROP treatments were laser therapy, intravitreal injection (IVI) of anti-vascular endothelial growth factor, or their combination. Stereoacuity was measured using the Titmus Stereo Test, and the results among various age groups were analyzed. Results: Stereopsis was found to improve with increasing age at testing (P < 0.001) across the entire study population. The term group exhibited significantly better stereoacuity than the preterm group (P < 0.001). At 3–5 years and 6–8 years, the preterm children without ROP exhibited significantly better stereoacuity than did those with ROP (P < 0.001 and P = 0.02, respectively); however, at 9–11 years, both groups exhibited similar stereoacuity (P = 0.34). The stereoacuity in the children with untreated ROP was similar to that of the children with treated ROP in all age groups (P > 0.05). No significant differences in stereopsis were identified between children with ROP treated with laser versus with IVI (P > 0.05). From multivariate analysis, younger age at testing (P = 0.001) and younger gestational age (P < 0.001) were associated with poorer stereopsis. Conclusions: Stereopsis development gradually improved with age in all groups. The children born preterm exhibited poorer stereoacuity than those born term. Children with ROP treated with laser photocoagulation versus IVI may exhibit similar levels of stereoacuity. Younger age at testing and gestational age were independent risk factors for poorer stereoacuity. [ABSTRACT FROM AUTHOR]

Ivana Mravi&ccaron;i&cacute;,&ast; Selma Luka&ccaron;evi&cacute;,&ast; Ante Bariši&cacute;,&ast; Sudi Patel,&ast; Maja Boha&ccaron;,&ast; Alma Biš&ccaron;evi&cacute;,&ast; Nikica Gabri&cacute;&ast; Department of Cataract and Refractive Surgery, University Eye Clinic Svjetlost, Zagreb, 10000, Croatia&ast;These authors contributed equally to this workCorrespondence: Sudi Patel, Department of Cataract and Refractive Surgery, University Eye Clinic Svjetlost, Heinzelova 39, Zagreb, 10000, Croatia, Email drsudipatel1@gmail.comPurpose: To determine if the changes in stereoacuity and aniseikonia, following bilateral implantation of presbyopia correcting intraocular lenses could be predicted from preoperative measurements of higher order aberrations (HOAs), axial lengths (AL), refractive errors (RE) and corrected visual acuities (CVAs).Patients and Methods: Stereoacuity (Randot tests, @6m & 40cm, in steps of 20 arcsecs”) vertical and horizontal aniseikonia (Awaya test @6m, in steps of 1%) with best correction and HOAs (Shack-Hartmann aberrometer) were measured before, 3 and 6 months after uncomplicated bilateral phacoemulsification. Twenty patients (I) underwent a mix-and-match procedure (Tecnis MF, ZKB00 in one eye and ZLB00 in the other), 17 (II) were implanted with a trifocal (AT LISA 839 triMP) and 18 (III) with a one-piece diffractive (Synergy OU) intraocular lens. The resultant aniseikonia (AR) of vertical and horizontal pairs of aniseikonia measurements was calculated using the Pythagorean theorem. Twenty untreated age/gender matched cases were recruited as controls (IV).Results: The key results (p < 0.001) were a) stereoacuity at distance (SAD) and near (SAN) improved, AR reduced in groups I, II & III remaining unchanged in group IV; b) some significant intergroup differences in SAD, SAN & AR were detected at postop; c) at 6 months postop, changes (Δ=pre- minus postoperative value) correlated with preoperative values (x). Linear regression revealed, I ΔSAD=0.66x-57.47 [0.832, ± 66.4], ΔSAN=0.96x-34.59 [0.821, ± 16.9], ΔAR=0.93AR-2.12 [0.795, ± 1.4] II ΔSAD=0.79x-62.91 [0.916, ± 38.1], ΔSAN=0.96x-31.49 [0.892, ± 8.0], ΔAR=0.91AR-0.91 [0.839, ± 1.3] III ΔSAD=0.67x-35.50 [0.991, ± 23.7], ΔSAN=0.88x-38.51[0.988, ± 10.6], ΔAR=0.86AR-0.96 [0.900, ± 1.3]. Figures in parentheses are the corresponding rs and ±limits of agreement between actual and estimated values. Definitive overarching associations connecting interocular differences in HOAs, AL, RE, and CVAs with SAD, SAN and AR were not found.Conclusion: Changes in stereoacuity and aniseikonia can be predicted using preoperative values. ΔSAN can be predicted within ± 1, and ΔAR within ± 2, scale divisions. In group III ΔSAD can be predicted within ± 1, and in group I ± 3, scale divisions.Keywords: presbyopia-correcting intraocular lenses, aberrometry, stereoacuity, aniseikonia

Background Stereoacuity is essential for depth perception and daily activities, complementing visual acuity. Assessing stereoacuity in children is vital for detecting binocular vision disorders and amblyopia. This study aimed to compare the Toegepast Natuurwetenschappelijk Onderzoek (TNO) test and the Titmus Fly test in school-based vision screening for children aged 6-12 years. Methods A cross-sectional study was conducted in social service settings with 122 elementary school children aged 6-12 years. Examinations included visual acuity, refraction, Ishihara color vision, and stereoacuity using both the TNO and Titmus Fly tests. Statistical comparisons were made using the Wilcoxon Signed-Ranks Test, and stereoacuity differences based on demographic factors and visual acuity were assessed using the Mann-Whitney U Test. The level of agreement between the two tests was determined using Bland-Altman analyses. Results Visual acuity significantly influenced stereoacuity results in the Titmus Fly test (p=0.001), with children having abnormal visual acuity performing worse. Approximately 68% of children reported that the Titmus Fly test was easier to perform. The mean difference between TNO and Titmus Fly measurements was 79.52 ± 63.75 (95% CI = 68.14–90.90; p=0.001), demonstrating a consistent bias between the two tests. Conclusion The Titmus Fly test is easier for children (6–12 years) to perform, but it tends to overestimate stereoacuity values compared to the TNO test, making the two methods non-interchangeable and not reliable. Stereoacuity assessment remains essential in school-based vision screening for evaluating binocular vision and amblyopia, especially in children with refractive errors.

Abstract Background To evaluate factors associated with better outcomes from optical treatment alone in amblyopic children from 3 up to 7 years. Methods Data extracted from two studies with similar protocols, Amblyopic Treatment Studies 5 (n = 152) and 13 (n = 128) from the Pediatric Eye Disease Investigator Group database, were used to determine by regression analysis the factors associated with improvements in visual acuity in the amblyopic eye, inter-ocular visual acuity difference and stereoacuity. Input variables were aetiology of amblyopia (anisometropic, strabismic and combined-mechanism amblyopia), treatment compliance, visual acuity, interocular visual acuity difference, stereoacuity, tropia size at distance and near, age and refractive error at baseline. Results Despite the range of clinical factors considered, our models explain only a modest proportion of the variance in optical treatment outcomes. The better predictors of the degree of optical treatment success in amblyopic children are visual acuity of the amblyopic eye, interocular visual acuity difference, stereoacuity, treatment compliance and the amblyopic eye spherical-equivalent refractive error. While the aetiology of the amblyopia does not exert a major influence upon treatment outcome, combined-mechanism amblyopes experience the smallest improvement in visual acuity, tropia and stereoacuity and may need longer optical treatment periods. Conclusions While results identify the factors influencing optical treatment outcome in amblyopic children, clinicians will be unable to predict accurately the benefits of optical treatment in individual patients. Whether this is because relevant clinical or non-clinical factors (e.g. nature and volume of daily activities undertaken) influences the outcomes from optical treatment has not yet been identified and remains to be discovered.

Purpose: A narrative review of the literature reporting ocular abnormalities in patients with schizophrenia was undertaken to determine the types and prevalence of orthoptic conditions in this patient cohort. Methods: A systematic search of multiple databases yielded 1,974 studies published between January 1992 and January 2022. All were screened for relevance based on their title and abstract. Results: Seventeen studies were included in the final review. Ocular abnormalities reported in schizophrenia included a high incidence of strabismus, reduced visual acuity and reduced stereopsis compared to controls. Additionally, eye movement abnormalities (including reduced smooth pursuit gain and increased prosaccade latency) were frequently reported. Reduced visual acuity was associated with negative symptoms and reduced quality of life in schizophrenia. Conclusions: Orthoptists and eye care professionals should be aware that a higher incidence of strabismus, reduced visual acuity, reduced stereoacuity, and eye movement abnormalities are reported in patients with schizophrenia. Further research is required to determine whether, or to what extent, ocular abnormalities and visual disturbances influence or exacerbate the symptoms of schizophrenia, and whether there is an effect of schizophrenia medication on these orthoptic conditions.

Purpose: A narrative review of the literature reporting ocular abnormalities in patients with schizophrenia was undertaken to determine the types and prevalence of orthoptic conditions in this patient cohort. Methods: A systematic search of multiple databases yielded 1,974 studies published between January 1992 and January 2022. All were screened for relevance based on their title and abstract. Results: Seventeen studies were included in the final review. Ocular abnormalities reported in schizophrenia included a high incidence of strabismus, reduced visual acuity and reduced stereopsis compared to controls. Additionally, eye movement abnormalities (including reduced smooth pursuit gain and increased prosaccade latency) were frequently reported. Reduced visual acuity was associated with negative symptoms and reduced quality of life in schizophrenia. Conclusions: Orthoptists and eye care professionals should be aware that a higher incidence of strabismus, reduced visual acuity, reduced stereoacuity, and eye movement abnormalities are reported in patients with schizophrenia. Further research is required to determine whether, or to what extent, ocular abnormalities and visual disturbances influence or exacerbate the symptoms of schizophrenia, and whether there is an effect of schizophrenia medication on these orthoptic conditions. [ABSTRACT FROM AUTHOR]

Purpose: To compare the motor and sensory outcomes of strabismus surgery and the factors affecting surgical success in acquired acute non-accomodative esotropia (ANAET) and partially accommodative refractive esotropia (pARET). Methods: A retrospective chart review of patients with ANAET and pARET who underwent unilateral or bilateral horizontal rectus muscle surgery between January 2020 and December 2021 was conducted. Patients with postoperative follow-up of at least six weeks were included. Patients with pattern deviation, lateral incomitance, and near-distance disparity were excluded. Motor success was defined as a postoperative deviation within eight prism diopters of orthophoria. Sensory success was defined as presence of binocular single vision (BSV) for both distance and near (Worth four dot test). The effect of factors like age at onset, age at surgery, amblyopia before surgery, duration of squint before treatment, presence or absence and magnitude of vertical deviation, preoperative angle of deviation, and spherical equivalent on the motor and sensory success in each group were analyzed and compared. Results: 38 patients with ANAET and 33 patients with pARET were included. The mean age of onset of esotropia was 8.55 ± 4.65 years and 4.39 ± 2.27 years (p <.001) and the mean age at surgery was 10.62 ± 4.99 years and 7.89 ± 2.84 years (p =.006) in the ANAET and the pARET group respectively. The mean duration of the final follow-up was 38.51 weeks in the ANAET and 48.68 weeks in the pARET group (p =.089). Patients were successfully aligned for both distance and near in 81.5% of patients in the ANAET and 78.9% of patients in the pARET group at the final follow-up (p. 0.775). A BSV for both distance and near at the final follow-up was seen in 81.2% vs 66.6% of patients in the ANAET and the pARET group respectively (p =.25). A good near stereoacuity (<120 arcsecs) was seen in 60.6% and 41.9% of the ANAET and the pARET groups respectively (p =.175). The percentage of patients in the ANAET group who had orthophoria, any esodeviation, and any exodeviation for distance at the final follow-up was 63.1%, 34.2% and, 2.6%. The percentage of patients in the pARET group in similar categories was 36.3%, 42.4% and, 21.2%. None of the demographic and preoperative factors were found to affect the surgical outcomes in the two groups. Conclusions: The motor and sensory outcomes were similar in the two groups. A higher proportion of ANAET patients remained orthophoric during the follow-up. The patients in the pARET group showed a tendency toward exodrift. [ABSTRACT FROM AUTHOR]

Background: To assess the relationship between self-reported and performance-based visual impairment (VI) and lower extremity physical function.Methods: Cross-sectional analysis of 2219 Health ABC participants who completed vision testing and the Short Physical Performance Battery (SPPB). Linear regression models used either self-reported (weighted visual function question (VFQ) score)) or performance-based (visual acuity (VA), log contrast sensitivity (LCS), Frisby stereoacuity (SA)) to predict SPPB or its components-gait speed, chair stands, or standing balance-with and without covariate adjustment.Results: Mean age was 73.5 years (range 69-80); 52.4% were female and 37.4% African American. All VI measures were strongly associated with SPPB in unadjusted and adjusted models (p<0.001). A self-reported VFQ score 1 standard deviation lower than the mean (mean 87.8 out of 100) demonstrated a -0.241(95% CI:-0.325, -0.156) adjusted difference in SPPB. After controlling for covariates, VA of <20/40 (41%) demonstrated a -0.496(-0.660, -0.331) lower SPPB score while SA score>85 arcsec (30%) had a -0.449(-0.627, -0.271) adjusted SPPB score versus those with better visual function. LCS<1.55 (28.6%) was associated with a -0.759(-0.938, -0.579) lower and LCS≤1.30 (8%) with a -1.216(-1.515, -0.918) lower adjusted SPPB score relative to better LCS. In a final multivariable model containing multiple vision measures, LCS remained independently associated with SPPB and all components, while SA remained associated with balance (all p<0.05).Conclusions: Both self-reported and performance-based VI are strongly associated with poor lower extremity physical function. These findings may identify a subgroup of older adults with co-existing visual and physical dysfunction who may benefit from targeted screening and intervention to prevent disability. [ABSTRACT FROM AUTHOR]

Background: To evaluate factors associated with better outcomes from optical treatment alone in amblyopic children from 3 up to 7 years. Methods: Data extracted from two studies with similar protocols, Amblyopic Treatment Studies 5 (n = 152) and 13 (n = 128) from the Pediatric Eye Disease Investigator Group database, were used to determine by regression analysis the factors associated with improvements in visual acuity in the amblyopic eye, inter-ocular visual acuity difference and stereoacuity. Input variables were aetiology of amblyopia (anisometropic, strabismic and combined-mechanism amblyopia), treatment compliance, visual acuity, interocular visual acuity difference, stereoacuity, tropia size at distance and near, age and refractive error at baseline. Results: Despite the range of clinical factors considered, our models explain only a modest proportion of the variance in optical treatment outcomes. The better predictors of the degree of optical treatment success in amblyopic children are visual acuity of the amblyopic eye, interocular visual acuity difference, stereoacuity, treatment compliance and the amblyopic eye spherical-equivalent refractive error. While the aetiology of the amblyopia does not exert a major influence upon treatment outcome, combined-mechanism amblyopes experience the smallest improvement in visual acuity, tropia and stereoacuity and may need longer optical treatment periods. Conclusions: While results identify the factors influencing optical treatment outcome in amblyopic children, clinicians will be unable to predict accurately the benefits of optical treatment in individual patients. Whether this is because relevant clinical or non-clinical factors (e.g. nature and volume of daily activities undertaken) influences the outcomes from optical treatment has not yet been identified and remains to be discovered. [ABSTRACT FROM AUTHOR]

Background: A clinician's choice of stereotest is influenced by the robustness of the measurement, in terms of sensitivity, specificity and test–retest variability. In relation to the latter aspect, there are limited data on the test–retest variability of these new tests and how they compare to the more commonly used stereotests. Therefore, the aim of the study was to determine the test–retest variability of four different measures of stereoacuity (TNO, Frisby, Lang Stereopad and Asteroid (Accurate STEReotest On a mobIle Device)) and to compare the stereoacuity measurements between the tests in an adult population. Methods: Stereoacuity was measured twice using TNO, Frisby, Lang Stereopad and Asteroid. Inclusion criteria included adult participants (18 years and older), no known ophthalmic condition and VA (Visual Acuity) equal to or better than 0.3 logMAR (Logarithm of the Minimum Angle of Resolution) with interocular difference of less than 0.2 logMAR. Bland–Altman analysis was used to assess agreement within and between stereotests. Differences in stereo thresholds were compared using signed Wilcoxon tests. Results: Fifty-four adults (male: 23 and female: 31) with VA equal to or better than 0.3 logMAR in either eye and interocular difference less than 0.2 logMAR were assessed (mean age: 38 years, SD: 12.7, range: 18–72). The test–retest variability of all the clinical stereotests, with the exception of the Lang Stereopad (p =.03, Wilcoxon signed-rank test), was clinically insignificant as the mean bias was equal or less than 0.06 log seconds of arc (equivalent to 1.15 seconds of arc). While the Asteroid test had the smallest variation between repeated measures (mean bias: −0.01 log seconds of arc), the Frisby and Lang Stereopad tests had the narrowest and widest limits of agreement respectively. When comparing results between tests, the biggest mean bias was between Frisby and Lang Stereopad (−0.62 log seconds of arc), and 64.8% and 31.5% of differences were in the medium (21–100" of arc) and larger (>100" of arc) ranges respectively. Conclusion: The TNO and Frisby tests have good reliability but measure stereoacuity over a narrower range compared to the Asteroid which shows less variation on repeated testing but has a larger testing range. The data reported here show varying degrees of agreement in a cohort of visually normal participants, and further investigation is required to determine if there is further variability when stereoacuity is reduced. [ABSTRACT FROM AUTHOR]

Abstract Background The aim of this observational study was to identify ocular and visual perceptive risk factors related to treatment results following refractive correction and patching in children with anisometropic amblyopia, who were between the ages of 4 to 14 years old. Methods One-hundred and two children with newly diagnosed anisometropic amblyopia were recruited. Successful treatment of amblyopia was defined as the final best corrected visual acuity (BCVA) better than or equal to 0.1 logMAR and amblyopic eye BCVA within 1 line of the sound eye BCVA by the end of the treatment period. BCVA, cycloplegic refraction, stereoacuity, perceptual eye position (PEP) and interocular suppression were measured. Results Of these patients, 45.10% achieved successful treatment of amblyopia after refractive correction and patching for 10.5 months. The mean age was not significantly different between patients who were successfully and unsuccessfully treated (5.50 ± 1.59 years vs 6.14 ± 2.19 years, respectively). Patients who failed treatment had significantly larger interocular difference of BCVA at the time of initial treatment (successful group: 0.33 ± 0.29 logMAR, unsuccessful group: 0.65 ± 0.35 logMAR) and after refractive adaptation (successful group: 0.15 ± 0.13 logMAR, unsuccessful group: 0.42 ± 0.35 logMAR). They also had higher spherical equivalent (SE) of amblyopic eyes (successful group: 3.08 ± 3.61 D, unsuccessful group: 5.27 ± 3.38 D), bigger interocular difference of SE (successful group: 0.94 ± 2.71 D, unsuccessful group: 3.09 ± 3.05 D), worse stereoacuity (successful group: 2.32 ± 0.37 log seconds of arc, unsuccessful group: 2.75 ± 0.32 log seconds of arc), larger vertical PEP deviation (successful group: 6.41 ± 6.08 pixel, unsuccessful group: 19.07 ± 24.96 pixel) and deeper interocular suppression (successful group: 21.7 ± 19.7%, unsuccessful group: 37.8 ± 27.1%) than those of successfully treated patients. The most influential treatment failure risk factors were larger vertical PEP deviation [adjusted odds ratio (OR) (95% confidence interval) 1.12 (1.02–1.22)] and worse stereoacuity [adjusted odds ratio (OR) (95% confidence interval) 7.72 (1.50–39.85)] in multiple logistic regression analysis. Conclusions Larger vertical PEP deviation and worse stereoacuity were the most influential treatment failure risk factors in children with anisometropic amblyopia. The vertical PEP deviation and stereoacuity, which can reflect interocular interaction, may be useful in predicting the response to therapy.

Background: Stereopsis plays a significant role in our visual system because it allows perception of depth to perform day-to-day activities. Aim: The aim of this study was to determine the severity and proportions of monocular versus binocular-induced blur on stereoacuity using the Randot® Stereo Test (RST) at near (40 cm). Setting: Data were collected at the optometry clinic of the University of Johannesburg. Methods: The study used a cross-sectional, experimental and prospective design with a quantitative approach. Forty university students between the ages of 18 years and 25 years were invited to participate in this study. Blur was induced monocularly and binocularly through 1 dioptre (D) to 3 D lenses and stereoacuity was measured using the RST at near (40 cm). Results: Stereoacuity measured with the added 1 D to 3 D lenses monocularly and binocularly resulted in reduced stereopsis, which was worse monocularly, found not to be significant (p = 0.17) with the addition of the 1 D lens(es) monocularly and binocularly. Significant reductions in stereoacuity were found with the addition of 2 D (p = 0.00) and 3 D (p = 0.00) monocularly and binocularly, respectively. Conclusion: The effect of induced optical blur monocularly on stereoacuity impacted significantly compared with induced binocular blur. However, the different accommodative amplitudes could have affected monocularly and binocularly induced stereoacuity for some participants. Contribution: The study is clinical and focuses on the effect of induced blur monocularly and binocularly on stereoacuity. Key insights are that the effect of induced optical blur monocularly impacted significantly on stereoacuity compared with induced blur binocularly.

Introduction: Amblyopia is a condition with reduced best corrected visual acuity in absence of any ocular pathology. Different treatment approaches of amblyopia have been researched for decades. Recent studies on binocular dichoptic therapy using different software and video game based training showed drastic improvement in visual functions in amblyopic adults. Aim of this review is to assess the effect of vision therapy with dichoptic training in adults with anisometropic amblyopes. Method: Review was conducted in articles published within last 25 years from databases like PubMed, research gate, google scholar. Results: Dichoptic therapy has promising results in treatment of adults with anisometropic amblyopia. However, several limitations of these said researches were observed. Conclusion: Further studies particularly RCTs with strict methodology and treatment protocol, larger sample size and longer follow ups are recommended before clinicians could impart dichoptic therapy as a management option of adults with amblyopia into their evidence based practice. [ABSTRACT FROM AUTHOR]

(1) Background: Amblyopia is an ocular condition leading to structural and functional changes. The relationship between these changes is complex and remains poorly understood. (2) Methods: Participants included 31 children aged 5 to 9 years with strabismic (n = 9), anisometropic (n = 16) and mixed (n = 6) unilateral amblyopia, and 14 age-matched non-amblyopic children. The 95% and 63% Bivariate Contour Ellipse Area (BCEA), axial length, Foveal Avascular Zone (FAZ) area, center macular thickness and volume were assessed. The relationship between these parameters was explored. (3) Results: Statistically significant differences were found among the four groups in best corrected distance visual acuity (BCVA) (p < 0.001), BCEA 95% (p = 0.002) and BCEA 63% (p = 0.002), but not in the FAZ area, central macular thickness, central macular volume and axial length. Eyes with amblyopia had poorer BCVA and larger fixation instability than controls. Inter-ocular differences were more significant in patients with strabismic amblyopia, particularly in BCVA (p = 0.003), central macular thickness (p < 0.001) and central macular volume (p = 0.002). In amblyopic eyes, BCEA 95% and 63% were correlated with BCVA, but not with the FAZ area. (4) Conclusion: Amblyopia is associated with a reduction in fixation stability and BCVA, although there is a general lack of correlation with structural changes, suggesting a complex interaction between anatomy and function in amblyopia. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effectiveness of combined use of stereoscopic 3D video movies and part-time patching in treating older amblyopic children with poor response or compliance to traditional patching treatments and comparing this combined treatment with patching alone. Methods: Thirty-two children aged 5–12 years with amblyopia associated with anisometropia, strabismus, or both were recruited in a randomized clinical trial. Eligible participants were assigned randomly to the combined and patching groups. Here, binocular treatment refers to using the Bangerter filter to blur the fellow eye and subsequently watching a close-up 3D movie with large parallax. The primary outcome was amblyopic eye (AE) best-corrected visual acuity (BCVA) improvement at six weeks. In addition, secondary outcomes included BCVA of AE improvement at three weeks and change of stereoacuity. Results: Of 32 participants, mean (SD) age was 6.63 (1.46) years, and 19 (59%) were female. At 6 weeks, mean (SD) amblyopic eye VA improved by 0.17 ± 0.08 logMAR (2-sided 95% CI, 0.13 to 0.22; F = 57.2, p < 0.01) and 0.05 ± 0.04 logMAR (2-sided 95% CI, 0.05 to 0.09; F = 8.73, p = 0.01) in the combined and patching groups, respectively. The difference was statistically significant (mean difference, 0.13 logMAR [1.3 line]; 95% CI, 0.08–0.17 logMAR [0.8–1.7 lines]; t25 = 5.65, p < 0.01). After treatment, only the combined group had significantly improved stereoacuity, such as binocular function score (median [interquartile range], 2.30 [2.23 to 2.68] vs. 1.69 [1.60 to 2.30] log arcsec; paired, z = –3.53, p < 0.01), and mean stereoacuity gain was 0.47 log arcsec (± 0.22). Changes in other types of stereoacuity were similar. Conclusion: Our laboratory-based binocular treatment strategy engaged a high level of compliance that led to a substantial gain in visual function after a short period of treatment for older amblyopic children having poor response or compliance to traditional patching treatments. Notably, the improving stereoacuity showed a greater advantage. [ABSTRACT FROM AUTHOR]

Impaired stereoacuity is seen in some children without amblyopia, strabismus, and clinically significant refractive errors. Therefore, there are probably other factors affecting stereoacuity. The aim of this work was to investigate the longitudinal changes of local stereoacuity and associated factors in schoolchildren. The present report is a part of the Shahroud Schoolchildren Eye Cohort Study. The target population was children aged 6 to 12 years in Shahroud, Iran. The second phase of the study was conducted in 2018 by re-inviting all participants in the first phase (2015). After an initial interview, study participants underwent optometric examination and ocular biometry. Stereoacuity was evaluated using Stereo Fly Test. Exclusion criteria were functional amblyopia, strabismus, significant refractive errors, probable ocular pathology/organic amblyopia in either of the two study phases, a history of intraocular surgery or ocular trauma, and incomplete data. The data of 4666 children were analysed for this report, of which 53.7% were male. The mean age of the studied participants in the second phase was 12.37 ± 1.71 years. The mean stereoacuity was 42.31 (95% CI: 42.05 − 42.57) seconds of arc in the first phase, which reduced to 51.72 (95% CI: 50.79-52.65) seconds of arc in the second phase (P < 0.001). The prevalence of poor stereoacuity was 0.17% (95% CI: 0.06-0.29) in the first phase, which increased to 3.94% (95% CI: 3.34-4.54) in the second phase (P < 0.001). According to the multiple linear regression, older age in the first study phase (β = 0.011, P < 0.001), urban residence (β = −0.019, P = 0.006), increased spherical anisometropia (0.038, P = 0.013), and increased axial length (β = 0.062, P = 0.003) were significantly associated with reduction of stereoacuity (in log scale) after three years. In addition to the known risk factors of amblyopia, strabismus, and significant refractive errors, other factors are also associated with stereoacuity changes in children. [ABSTRACT FROM AUTHOR]

Objective: It was aimed to investigate the relationship of stereoacuity with retinal nerve fiber layer thickness (RNFLT) and P100 latency in multiple sclerosis (MS) patients with and without optic neuritis (ON). Materials and Methods: Twenty-nine patients diagnosed with clinically definite MS with and without a history of ON were included in this prospective study. Patients without ON were classified into relapsing-remitting MS (RRMS) and single-attack MS (SAMS) subgroups. There were 11 patients in the RRMS group with ON (ON-RRMS), 11 patients with RRMS and 7 patients with SAMS in the MS group without ON, and 16 healthy subjects in the control group. Stereoacuity was determined by the TNO and Titmus tests. RNFLT was measured by spectral domain-optical coherence tomography and P100 latency was measured in pattern visual evoked potential recordings. The results were analyzed with the SPSS 20 statistical program. P

The clinical assessment of distance stereoacuity is important in some ocular conditions. Given the different neurophysiological mechanism for crossed and uncrossed stereoacuities, evaluation of both may provide additional insight into binocular vision disorders. Clinical devices measuring distance crossed and uncrossed stereopsis are not readily available. Visotec Distance Stereo Test (VDST) is a contour-based device designed to measure both forms of distance stereoacuity. This study assesses the validity and test–retest reliability of the device in comparison to the random dot-based Randot Distance Stereo Test (RDST). VDST and RDST were administered to a total of 107 children, that included 51 'normal' and 56 'abnormal' (37 intermittent exotropia and 19 amblyopia) between the ages of 5 and 15 years. Two examiners retested stereoacuities in a sub-set of 62 randomly selected subjects. Stereoacuity was transformed to log scale. 95% limits of agreement were calculated for test–retest reliability. The Bland–Altman plot was used to demonstrate the agreement between the tests and the examiners. The mean ± SD crossed distance stereoacuities using VDST in normal, intermittent exotropia and amblyopic children were 93.1 ± 43.8, 161.9 ± 89.8 and 236.3 ± 122.4 arcseconds, respectively. For uncrossed stereoacuity, these were 104.7 ± 54.0, 187.6 ± 89.6 and 265.5 ± 144.0 arcseconds, respectively. Crossed stereoacuity was significantly better than uncrossed stereoacuity. 95% limits of test–retest agreement for crossed and uncrossed stereoacuities using the VDST were 0.27 and 0.30, respectively. An exact test–retest match using VDST was 84% in normals and 77% in abnormals for crossed and 83% in normal and 74% in abnormal for uncrossed stereoacuities. VDST is a reliable, valid and easy-to-administer distance crossed and uncrossed stereoacuity measuring device. Further studies are required to establish the clinical importance of assessing these two forms stereoacuities in relation to various binocular vision disorders. [ABSTRACT FROM AUTHOR]

AIM: To compare the effectiveness of network-based perception learning (NBPL) and traditional training in the treatment of amblyopia children. METHODS: This randomized controlled clinical trial recruited 56 participants aged 4-12y with anisometropic and/or strabismic amblyopia. Participants were randomly divided into two groups: the NBPL group (n=28) who received patching and NBPL for 3mo, and the control group (n=28) who got 3mo of patching and traditional training. Best-corrected visual acuity (BCVA) in the amblyopic eye and stereoacuity were measured and compared at baseline, 1, 2, and 3mo post-randomization. RESULTS: There were no significant differences in age, gender ratio, and BCVA between the two groups at baseline. At 3mo, most patients gained lines (2 logMAR lines on average) of BCVA in both groups except one 11-year-old girl in the control group (P

Background: The aim of this observational study was to identify ocular and visual perceptive risk factors related to treatment results following refractive correction and patching in children with anisometropic amblyopia, who were between the ages of 4 to 14 years old. Methods: One-hundred and two children with newly diagnosed anisometropic amblyopia were recruited. Successful treatment of amblyopia was defined as the final best corrected visual acuity (BCVA) better than or equal to 0.1 logMAR and amblyopic eye BCVA within 1 line of the sound eye BCVA by the end of the treatment period. BCVA, cycloplegic refraction, stereoacuity, perceptual eye position (PEP) and interocular suppression were measured. Results: Of these patients, 45.10% achieved successful treatment of amblyopia after refractive correction and patching for 10.5 months. The mean age was not significantly different between patients who were successfully and unsuccessfully treated (5.50 ± 1.59 years vs 6.14 ± 2.19 years, respectively). Patients who failed treatment had significantly larger interocular difference of BCVA at the time of initial treatment (successful group: 0.33 ± 0.29 logMAR, unsuccessful group: 0.65 ± 0.35 logMAR) and after refractive adaptation (successful group: 0.15 ± 0.13 logMAR, unsuccessful group: 0.42 ± 0.35 logMAR). They also had higher spherical equivalent (SE) of amblyopic eyes (successful group: 3.08 ± 3.61 D, unsuccessful group: 5.27 ± 3.38 D), bigger interocular difference of SE (successful group: 0.94 ± 2.71 D, unsuccessful group: 3.09 ± 3.05 D), worse stereoacuity (successful group: 2.32 ± 0.37 log seconds of arc, unsuccessful group: 2.75 ± 0.32 log seconds of arc), larger vertical PEP deviation (successful group: 6.41 ± 6.08 pixel, unsuccessful group: 19.07 ± 24.96 pixel) and deeper interocular suppression (successful group: 21.7 ± 19.7%, unsuccessful group: 37.8 ± 27.1%) than those of successfully treated patients. The most influential treatment failure risk factors were larger vertical PEP deviation [adjusted odds ratio (OR) (95% confidence interval) 1.12 (1.02–1.22)] and worse stereoacuity [adjusted odds ratio (OR) (95% confidence interval) 7.72 (1.50–39.85)] in multiple logistic regression analysis. Conclusions: Larger vertical PEP deviation and worse stereoacuity were the most influential treatment failure risk factors in children with anisometropic amblyopia. The vertical PEP deviation and stereoacuity, which can reflect interocular interaction, may be useful in predicting the response to therapy. [ABSTRACT FROM AUTHOR]

Purpose: To compare the stereoacuity in patients with anisometropia, isometropia, and emmetropia.Methods: A cross-sectional study was conducted on 1403 subjects (range: 5-45 years) divided into anisometropes (n = 403), isometropes (n = 500), and emmetropes (n = 500). There were 258 amblyopic eyes among anisometropes and 156 amblyopic eyes among isometropes. Stereoacuity was measured using the Titmus stereo test consisting of a combination of contour targets.Results: There were 675 males and 728 females. A significant (P < 0.001) reduction in stereoacuity was found in anisometropes as compared to isometropes and emmetropes. The stereoacuity was even worse in amblyopes as compared to non-amblyopes. Most patients with anisometropia of <3.0 D had fair stereoacuity. However, as the degree of anisometropia increased to >3.0 D, stereoacuity deteriorated gradually. Marked reduction of stereoacuity was observed in severe degree of anisometropia (>6.0 D). Overall, an anisometropia of ≥2.12 D was associated with reduced stereoacuity. Among the anisometropes, it was found to be the poorest in myopia, followed by myopia with astigmatism, hypermetropia with astigmatism, and hypermetropia.Conclusion: The level of stereoacuity was worse in anisometropes as compared to isometropes and emmetropes. Amblyopes had a greater reduction in stereoacuity than non-amblyopes. Stereoacuity decreased as the degree of anisometropia increased. Among the anisometropes, myopes had worst stereoacuity than hypermetropes. [ABSTRACT FROM AUTHOR]

Introduction: Stereoacuity, like many forms of hyperacuity, improves with practice. We investigated the effects of repeated measurements over multiple visits on stereoacuity using two commonly utilised clinical stereotests, for both crossed and uncrossed disparity stimuli. Methods: Participants were adults with normal binocular vision (n = 17) aged between 18 and 50 years. Stereoacuity was measured using the Randot and TNO stereotests on five separate occasions over a six week period. We utilised both crossed and uncrossed stimuli to separately evaluate stereoacuity in both disparity directions. A subset of the subject group also completed a further five visits over an additional six week period. Threshold stereoacuity was determined by the lowest disparity level at which the subjects could correctly identify both the position and disparity direction (crossed or uncrossed) of the stimulus. Data were analysed by repeated measures analysis of variance. Results: Stereoacuity for crossed and uncrossed stimuli improved significantly across the first five visits (F1,21 = 4.24, p = 0.05). The main effect of disparity direction on stereoacuity was not significant (F1 = 0.02, p = 0.91). However, a significant interaction between disparity direction and stereotest was identified (F1 = 7.92, p = 0.01). Conclusions: Stereoacuity measured with both the TNO and Randot stereotests improved significantly over the course of five repetitions. Although differences between crossed and uncrossed stereoacuity were evident, they depended on the stereotest used and reduced or disappeared after repeated measurements. A single measure of stereoacuity is inadequate for properly evaluating adult stereopsis clinically. [ABSTRACT FROM AUTHOR]

Background: Amblyopia is a common cause of visual impairment in children. Compliance with traditional treatments for amblyopia is challenging due to negative psychosocial impacts. Recent shifts in amblyopia treatment have moved from suppressing the dominant eye to enhancing binocular visual function. Binocular digital therapy has become a promising approach., Objective: The aim of this study was to evaluate the effects of binocular gamified digital therapy on visual acuity and stereoacuity (SA) in children with unilateral amblyopia., Methods: This pilot prospective study enrolled 11 children aged 4-6 years with unilateral amblyopia. Following at least 8 weeks of refractive correction, participants underwent binocular gamified digital therapy for 60 minutes per day, 5 days a week. The therapy used a roguelike shooting game delivered under binocular conditions through two independent channels with a real-time artificial intelligence visual engine. Assessments of distance visual acuity (DVA), near visual acuity (NVA), and SA were conducted at baseline and again at 4, 8, and 12 weeks., Results: At 12 weeks, the following significant improvements were noted: amblyopic eye DVA improved by 1.0 line (P=.01; d=0.77), binocular DVA improved by 0.7 lines (P=.006; d=1.00), and SA improved by 0.3 logarithm (log) arcseconds (P=.01; d=0.97). At 8 weeks, improvements included amblyopic eye DVA by 0.9 lines (P=.046; d=1.00) and SA by 0.28 log arcseconds (P=.02; d=0.90). No significant adverse events were observed, although one participant developed progressive esotropia., Conclusions: Binocular gamified digital therapy is effective and safe for improving visual outcomes in children aged 4-6 years with unilateral amblyopia., (© Wenqing Zhu, Shuneng Gu, Jian Li, Jin Lin, Chanling Hu, Rui Liu. Originally published in JMIR Serious Games (https://games.jmir.org).)

Purpose: The study aimed to estimate the prevalence of subnormal stereoacuity in school children and to assess the factors associated with it. Methods: In this prospective cross-sectional study, a total of 2,376 school children without amblyopia and manifest squint were screened by the titmus fly test, Snellen chart, tests for heterophoria, anterior segment examination, and fundoscopy. Children with a manifest squint, amblyopia (best-corrected visual acuity [BCVA]

Abstract Background To evaluate depth perception in Primary open angle glaucoma (POAG), glaucoma suspects compared to controls and to determine the association between depth perception and severity of glaucoma. Methods This was a hospital based, comparative, cross-sectional study. The ethical clearance was taken from institutional review committee of Institute of Medicine [Reference no.399 (6–11) E2 077-078]. Agematched, equal number of participants in each group (N=20) were evaluated with both Titmus and Frisby stereoacuity tests to measure depth perception as stereopsis threshold in seconds of arc. The participants were selected using the purposive sampling technique. Results There was no differences in age, sex, or best corrected visual acuity, intraocular pressure, central corneal thickness (CCT), found among the three groups (POAG, Glaucoma Suspects and Control) respectively. However, there was significant difference in cup disc ratio (CDR) between the groups. Equal number of male and female were there in each group, while in POAG group male to female ratio was 3:2. The mean stereoacuity threshold in control group was 53.5±23.23 seconds of arc with Titmus test and 38.75±18.83 seconds of arc with Frisby stereoacuity test. The difference in threshold was significant between control and glaucoma suspect with Titmus (t=1.991, p=0.05) and with Frisby (t=2.114, p=0.04). The difference was also significant in POAG group by Titmus (t=3.135, p=0.0033) and by Frisby (t=3.014, p=0.004). More so, with increasing severity of glaucoma, the mean threshold of stereopsis increased as seen with both Titmus and Frisby Tests (ANOVA, p < 0.001) Conclusion Primary open angle glaucoma patients and glaucoma suspects, showed significant reduction in depth perception. Decreased stereoacuity was associated with greater glaucomatous visual field loss.

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Juan Antonio Portela-Camino,1 Santiago Martín-González,2 Javier Ruiz-Alcocer,3 Igor Illarramendi-Mendicute,4 Rafaela Garrido-Mercado3 1Department of Optometry, Begira Clinic, Bilbao, Spain; 2Department of Construction and Manufacturing Engineering, University of Oviedo, Oviedo, Asturias, Spain; 3Department of Optometry and Vision Science, Complutense University of Madrid, Madrid, Spain; 4Department of Optometry, Begitek Clinic, Donostia, SpainCorrespondence: Juan Antonio Portela-CaminoDepartment of Optometry, Begira Clinic, C/ Ibáñez de Bilbao, nº 10, Bilbao, 48001, Bizkaia, SpainTel +34 94 605 39 67Email juanportel@hotmail.comPurpose: Stereo-anomaly is commonly associated with amblyopia. An investigation was conducted to determine whether the measurements of stereoacuity obtained with the stereoacuity reference test (TNO Test) show an agreement with a computer stereoscope video game.Methods: Thirty-two subjects (mean age 9.37± 2.00 years) with an amblyopia history were selected for a blind and randomized study of stereoacuity improvement through a new random dot game. A masked examiner measured the stereoacuity three times per subject using the TNO test (at the beginning, at the end and after 6 months of the treatment). A second masked examiner measured stereoacuity using the new computerized game after the TNO masked evaluation.Results: The Pearson’s correlation coefficient one test against the other was r2 = 0.767 and the Bland–Altman plot was r2= 0.069 (mean difference − 0.03 log sec). Using three categories: poor (840– 300 seconds of arc), coarse (480– 210 seconds of arc) and moderate–fine stereoacuity (210– 30 seconds of arc). Positive predictive values were 89.5% for moderate–fine; 72.7% for coarse; and 90.0% for poor stereoacuity. In addition, the agreement was evaluated using the Kappa coefficient (K= 0.743) with a 0.95 confidence interval and lower and upper Kappa limits were (0.628 and 0.858), respectively. Kappa coefficient and limits were still good when analyzing data before (K =0.663, 0.420 and 0.906) and after the treatment (K= 0.765, 0.632 and 0.899).Conclusion: The Computerized Stereoscopic Game test allows the measure of stereoacuity. It can be used for both the purpose of detecting stereo vision deficits or tracking stereo vision development.Keywords: amblyopia, computerized game test, gamification, stereoacuity, TNO test

Mikias Mered Tilahun, Mohammed Seid Hussen, Getasew Alemu Mersha, Biruk Lelisa Eticha Department of Optometry, School of Medicine, University of Gondar, Comprehensive Specialized Hospital, Gondar, EthiopiaCorrespondence: Getasew Alemu Mersha POB: 196 Tel +251932823935Fax +251-058-114 1240Email gechopta12@gmail.comPurpose: This study aimed to assess the level of stereopsis, proportion of poor stereopsis, and factors influencing stereopsis in adults with refractive error.Methods: This was a cross-sectional, descriptive study conducted on 153 adults with refractive error at Gondar University Hospital Tertiary Eye Care Center from April 08 to June 07, 2019. Structured questionnaires and ophthalmic instruments (Retinoscope, Worth Four Dot test and TNO Stereo plates) were used to collect the data. Data were entered and analyzed with Statistical Package for Social Sciences (SPSS) version 20. The result was summarized using summary statistics such as mean. Chi-squared test of association was applied between stereopsis and independent variables.Results: The level of stereopsis after correction of refractive error ranged from 1.89 to 2.65 log arc second. Before correction of refractive error, poor stereopsis was observed in 46.4% of the participants, while after correction, it dropped to 39.8% (CI: 95%: 31.1%– 47.8%). Stereopsis after correction had a significant association with age, best visual acuity, type of refractive error, and fusional status at distance with a p value < 0.05.Conclusion: Given refractive error corrected, the mean stereopsis in patients with refractive error was 2.42 log arc second. Proportion of poor stereopsis was noted in 39.8% of the participants corrected for refractive error. Age, best corrected visual acuity, type of refractive error, and fusional status had a significant association with stereopsis. Further studies on stereoacuity on a large scale are recommended.Keywords: stereoacuity, poor stereoacuity, refractive error, Gondar, Ethiopia

Background: Minimally Invasive Surgery (MIS) has an impact on surgeons' musculoskeletal and visual systems. However, the relationship between visual symptoms and musculoskeletal problems is not well understood. Aim of the study: This study used surface electromyography (sEMG) to examine changes in fatigue of the neck/shoulder muscles among surgeons with visual impairments when performing simulated surgical tasks in 2D and 3D viewing modes. Design: Cross-sectional laboratory study. Methods: Changes in median frequency (MDF, an indicator of muscle fatigue) were examined in 17 experienced gynaecologists. Four simulated surgical laparoscopy tasks were performed in 2D and 3D viewing modes. The MDF of three neck/shoulder muscles (cervical erector spinae, [CES], upper trapezii [UT], and anterior deltoids [AD]) were examined bilaterally. Visual parameters (accommodation, convergence, and stereoacuity) were measured prior to commencement. Results: There was a downward shift of MDF from simple to more complex tasks for the right and left CES and AD muscles but not the UT, which was consistent for surgeons with mild accommodation/convergence impairment and/or good stereoacuity. There were significant differences in the level of muscle fatigue of the neck/shoulder muscles according to the severity of visual impairment, muscle side, task and surgical performance level. Conclusions: The results show a relationship between the degree of visual impairments and muscle fatigue of the neck/shoulder muscles among MIS surgeons. These findings have important implications in understanding the concurrence of musculoskeletal problems and visual symptoms. [ABSTRACT FROM AUTHOR]

The main objective of this study was to obtain percentile curves of stereoacuity in arc seconds for a Spanish population aged between three and twelve years of age. A descriptive, observational and transversal study was conducted, which included children aged between three and twelve years of age who did not present with any known ocular and/or systemic diseases. The convenience sampling method was used to select the sample from three schools and one hospital in the Community of Madrid. The Bueno-Matilla Vision Unit's random dot test was used to measure stereoacuity. A descriptive statistic was performed with the stereoacuity values that were obtained for the 5th, 10th, 25th, 50th, 75th, 90th and 95th percentiles. The stereoacuity values of 1300 children were analysed. In the 50th percentile curve, it was determined that stereoacuity values close to 40 sec/arc were present from four years of age, and at four years and nine months, stereoacuity values close to 28 sec/arc were already being observed within said percentile, with values that were similar to those expected in the adult population. A progressive increase was observed, reaching 19 sec/arc before six years of age, with this stereoacuity value becoming more established in children from seven years of age. Although given the specific type of sampling that was performed it was not possible to generalise the results to the entire population, these percentile curves may aid paediatric professionals in their assessment of the development of this visual ability, which is indicative of the degree of development of binocular vision. [ABSTRACT FROM AUTHOR]

PURPOSE: Refractive correction and patching is the timetested mainstay of treatment for anisometropic amblyopia within the critical period of visual development. Binocular therapies using dichoptic training which overcome suppression by balancing the contrast between two eyes has been increasingly gaining ground. We evaluated the efficacy of dichoptic training in the adult population with anisometropic amblyopia. This study aims to evaluate the effectiveness of dichopticbased active vision therapy, using "VisuoPrime" software as primary intervention, in adults with anisometropic amblyopes. MATERIALS AND METHODS: A prospective interventional study in adults (18-40 years) with anisometropic amblyopia was conducted from August 2019 to March 2020. METHODS: Twentynine subjects with anisometropic amblyopia played binocular games through "VisuoPrime" software 30 min daily for 6 weeks. Bestcorrected visual acuity (BCVA) and binocularity was assessed at 1 and 3 months. Student's paired ttest, Wilcoxon signedrank sum test and MannWhitney tests were used. Statistical package of SPSS version 20.0 was used for analysis, considering P < 0.05 as statistically significant. RESULTS: BCVA of the amblyopic eye improved from 0.60 ± 0.40 logMAR to 0.45 ± 0.29 logMAR and 0.38 ± 0.23 logMAR at 1 and 3 months, respectively (P = 0.0001). Near acuity improved from 0.21 ± 0.14 to 0.14 ± 0.08 logMAR and 0.1 ± 0.04 logMAR at 1 and 3 months respectively (P < 0.0001). Improvement in stereopsis was observed in 24% of subjects which maintained at 3 month followup. CONCLUSION: Dichopticbased active vision therapy using "VisuoPrime" software was effective as a primary modality in adults with anisometropic amblyopia. [ABSTRACT FROM AUTHOR]

Purpose: To systematically review the published manuscripts on stereopsis after corneal refractive surgery. Methods: The Web of Science, PubMed, Scopus, ProQuest, Clinical Key, Embase, and Cochrane Library were searched for relevant articles published until August 2020. The fixed- or random-effects models were used to estimate the Weighted mean difference (WMD) or Relative risk (RR) and 95% Confidence interval (CI) for postoperative stereopsis changes and incidence when applicable. Meta-regression was conducted for adjusting the effects of potential confounders. Results: Seven studies (1266 eyes) in adults and ten studies in pediatrics (259 eyes) were included. In adults, stereopsis improved significantly compared to the preoperative state (WMD = − 27.4, 95% CI = − 40.0, − 14.7; I2 = 97.8%; P < 0.001). In pediatrics, proportion of patients with stereoacuity postoperatively was 2.18 times compared to preoperative evaluation. (RR = 2.18, 95% CI = 1.2, 3.9; I2 = 68.6%, P < 0.001). Conclusions: Stereopsis improves after corneal refractive surgery in adults and pediatrics. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study was to evaluate strabismus, stereoacuity, accommodation and convergence in prematurely born young adults; screened for retinopathy of prematurity in the neonatal period and compare with term‐born individuals of the same age. Materials and methods: The study participants included 59 prematurely born individuals with a birthweight of ≤1,500 grams and 44 term‐born controls, all born during 1988–1990 in Stockholm County, Sweden. Ocular alignment was assessed with a cover test, stereoacuity with the TNO stereo test and the amplitude of accommodation and the near point of convergence with the Royal Air Force Rule. Results: Seven of 59 (12%) preterms had manifest strabismus, 4/59 (7%) had esotropia and 3/59 (5%) exotropia. One of 44 (2%) controls had esotropia; no other controls had manifest strabismus. Stereoacuity was within normal limits in 38/59 (64%) preterms and 43/44 (98%) controls, p < 0.01; the difference remained after excluding those with strabismus. A neurological complication at 2.5 years of age was the strongest risk factor for subnormal stereoacuity within the preterm group after excluding those with strabismus. The mean amplitude of accommodation was poorer in the preterms than the controls in better (p < 0.05) and worse eyes (p < 0.05). The preterms were more likely to have an amplitude of accommodation below the minimum, according to Hofstetter's equation. There were no differences between the groups regarding the near point of convergence. Conclusion: Prematurely born young adults had a higher prevalence of strabismus, reduced stereoacuity and worse amplitude of accommodation than term‐born controls. [ABSTRACT FROM AUTHOR]

Past research has reported deficits on reaching and grasping tasks in adults with amblyopia and degraded stereoacuity, but less is known about visuomotor deficits in children—specifically, for complex tasks that require movement sequencing. This study therefore compared the visuomotor performance in 21 children with abnormal binocular vision (patient group) due to amblyopia and/or strabismus to that of 236 children with normal binocular vision development (control group) ages 5–14 years. Visual acuity, stereoacuity, and hand‐movement kinematics on a bead‐threading task were assessed. The patient group showed significantly longer durations than the control group on grasp, thread, and total movement durations. Both groups of participants were then split into immature (ages 5–9 years) and mature (ages 10–14 years) groups based on the maturation age for these parameters in control children. Grasp duration was longer in both mature and immature patient groups; thread and total movement durations were longer in the mature patient group only. Grasp duration was the most disrupted kinematic parameter in children with disrupted binocular vision due to amblyopia and/or strabismus, regardless of age. The level of stereoacuity loss rather than the depth of visual acuity loss was associated with the severity of visuomotor deficits. [ABSTRACT FROM AUTHOR]

Objectives: This research aimed to present a novel glasses-free distance random-dot stereotest system (GFDRDSS) using an eye-tracking method.Methods: A single-view autostereoscopic display applying a backlight control system combined with an eye-tracking method and the corresponding random-dot stereotest software were developed to create a GFDRDSS with a viewing distance of 5 m. The stereoacuity of 12 subjects with normal eye position was evaluated using the Randot Stereotest, Stereoscopic Test Charts vol. 3 (Yan’s Charts), Distance Randot® Stereotest, and GFDRDSS.Results: The GFDRDSS could provide distinct and stable glasses-free stereoscopic perception even while the subject was moving their head. It could evaluate binocular disparities of 40–2,400 arcsec. Eleven subjects with normal near visual acuity had fine near stereovision (20–60 arcsec) using the Randot stereotest and Yan’s Charts. Under refractive correction, 10 subjects had fine stereovision (≤60 arcsec) using the GFDRDSS at a distance of 5 m, and 9 had fine stereovision using the Distance Randot® Stereotest at 3 m. Other subjects described the 100 arcsec-level stereograms correctly. The results exhibited a concordance of stereoacuity within one degrade between the two distance stereotests.Conclusion: The proposed GFDRDSS can alternately project a couple of random-dot stereograms to the subjects’ eyes and provide a glasses-free distance stereotest, which showed good concordance with the Distance Randot® Stereotest. More data are needed for statistical studies.

Our sense of depth perception is mediated by spatial filters at different scales in the visual brain; low spatial frequency channels provide the basis for coarse stereopsis, whereas high spatial frequency channels provide for fine stereopsis. It is well established that monocular blurring of vision results in decreased stereoacuity. However, previous studies have used tests that are broadband in their spatial frequency content. It is not yet entirely clear how the processing of stereopsis in different spatial frequency channels is altered in response to binocular input imbalance. Here, we applied a new stereoacuity test based on narrow-band Gabor stimuli. By manipulating the carrier spatial frequency, we were able to reveal the spatial frequency tuning of stereopsis, spanning from coarse to fine, under blurred conditions. Our findings show that increasing monocular blur elevates stereoacuity thresholds 'selectively' at high spatial frequencies, gradually shifting the optimum frequency to lower spatial frequencies. Surprisingly, stereopsis for low frequency targets was only mildly affected even with an acuity difference of eight lines on a standard letter chart. Furthermore, we examined the effect of monocular blur on the size tuning function of stereopsis. The clinical implications of these findings are discussed.

Purpose: To evaluate binocular visual function after unilateral and bilateral implantation of segmented refractive multifocal intraocular lenses (MIOLs). Methods: This prospective comparative pilot study included patients who underwent SBL-3 (Lenstec; + 3.00 D) implantation at Peking University Third Hospital. Patients were divided into two groups (monocular or binocular surgery). Thirty-two patients with emmetropic presbyopic contralateral eyes and 49 patients with bilateral SBL-3 implantation within a week between eyes were included in the unilateral SBL-3 and bilateral groups, respectively. At 3-month follow-up, the main outcomes were binocular uncorrected distant, intermediate, and near visual acuity (UDVA, UIVA, and UNVA). Secondary outcomes included binocular best-corrected visual acuity at all distances, defocus curve, contrast sensitivity, photic phenomena, spectacle independence, patient satisfaction, and National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) score. The essential perceptual phenomena constituting binocular vision, simultaneous perception, fusion, and stereopsis were also evaluated. Results: Both groups showed similar binocular UDVA and UIVA, but UNVA was significantly better in the bilateral group (0.07 ± 0.07 versus 0.12 ± 0.07, P = 0.008). Better binocular defocus curve at intermediate to near focal points, higher percentage of spectacle independence at near distance, and NEI-VFQ-25 near activity scores were observed in the bilateral group. No significant differences in contrast sensitivity, photic phenomena, overall satisfaction, other NEI-VFQ-25 subscales, fusional amplitude, and stereoacuity were found between groups. Conclusion: Unilateral implantation of segmented refractive MIOL provided desirable distant visual acuity and high patient satisfaction, but inferior intermediate and near visual outcomes compared with bilateral implantation. [ABSTRACT FROM AUTHOR]

Purpose: To explore the distribution of stereoacuity and to examine its determinants in school-age children in Tibetan plateau, Southwest China. Methods: This is the cross-sectional part of a school-based cohort study of 7-year-old children in Lhasa, Tibet Autonomous Region, Southwest China. Children in first year of primary school were invited to undergo a comprehensive examination, including height, weight, visual acuity, cycloplegic autorefraction (1% cyclopentolate), anterior segment, cover and uncover test, and stereoacuity (Titmus Stereo Test). Results: A total of 1833 eligible subjects were included, with a mean age of 6.82 ± 0.46 years. Mean stereoacuity was 1.78 ± 0.21 in log units (median: 60 arcsec). Children with stereoacuity equal to 40 arcsec and stereoacuity worse than 100 arcsec accounted for 29.24% and 8.18% of the cohort, respectively. Tibetan ethnicity (OR = 1.98; 95%CI, 1.30–3.03), astigmatism (OR = 1.65; 95%CI, 1.26–2.17), strabismus (OR = 2.92; 95%CI, 1.38–6.18), and amblyopia (OR = 3.77; 95%CI, 1.14–12.49) were risk factors for normal stereoacuity (= 40 arcsec). Shorter height, younger age, strabismus, and worse BCVA (P < 0.05 for all) were both related to lower stereoacuity in Spearman correlation analysis and associated with lower stereoacuity in multivariate regression analysis. Conclusion: Stereoacuity maturation does not appear fully completed in 7-year-old children, while few children present stereoacuity worse than 100 arcsec (8.18%). Lower stereoacuity was associated with younger age, shorter height, strabismus, and lower best-corrected visual acuity. [ABSTRACT FROM AUTHOR]

Purpose: Mild to moderate vision loss affects many children and can negatively impact a child's early literacy and academic achievement. Nevertheless, there is no consensus on which factors present in early childhood indicate the need for long‐term ophthalmic follow up, particularly in children with a history of perinatal adversity. This study identified the relationship between visual, cognitive, motor and demographic factors at 2 years of age and visual acuity (VA) and stereoacuity at 4.5 years of age. Methods: Five hundred sixteen children identified as being at risk of neonatal hypoglycaemia were recruited soon after birth. At 2 years of age, binocular VA, stereoacuity and non‐cycloplegic refraction were measured and a clinical neuro‐developmental assessment with the Bayley Scales of Infant Development III (BSID‐III) was conducted by a trained examiner. Monocular VA and stereoacuity were measured at 4.5 years of age. Results: Three hundred twenty‐eight children completed both the 2 and 4.5 year vision and neurodevelopmental assessments. Multiple linear regression showed oblique astigmatism and motor function at 2 years were significantly associated with VA at 4.5 years of age, while spherical equivalent refraction, motor scores and stereoacuity at 2 years were significantly associated with stereoacuity at 4.5 years of age. BSID‐III motor scores had the best sensitivity (81.8%) and specificity (51.5%) for identifying impaired stereoacuity at 4.5 years. However, all measures at 2 years were poorly associated with VA at 4.5 years old. Conclusion: Vision and neurodevelopmental measures at 2 years were poorly associated with visual function at 4.5 years of age. However, lower scores on tests of motor function at 2 years may be associated with vision abnormalities, particularly reduced stereopsis, at 4.5 years of age and referral for comprehensive vision assessment for these children may be warranted. [ABSTRACT FROM AUTHOR]

Purpose: The study aimed to estimate the prevalence of subnormal stereoacuity in school children and to assess the factors associated with it.Methods: In this prospective cross-sectional study, a total of 2,376 school children without amblyopia and manifest squint were screened by the titmus fly test, Snellen chart, tests for heterophoria, anterior segment examination, and fundoscopy. Children with a manifest squint, amblyopia (best-corrected visual acuity [BCVA] <6/18), and history of ocular trauma or surgery, and one-eyed children were excluded. Cycloplegic refraction was done in children with uncorrected or undercorrected refractive errors, and stereoacuity was assessed again with spectacle correction.Results: The prevalence of normal stereoacuity by titmus fly test was 93.18% with correction of refractive errors. Girls had slightly better stereopsis compared with boys. The subnormal stereoacuity was significantly associated with refractive error (P < 0.00001, significant at P < 0.05), unilateral refractive error (P < 0.00001, significant at P < 0.05), bilateral refractive error (P < 0.00001, significant at P < 0.05), anisometropia (P < 0.00001, significant at P < 0.05), ametropia (P < 0.00001, significant at P < 0.05), lower BCVA (P < 0.00001, significant at P < 0.05), hyperopia (P < 0.05, significant at P < 0.05), and heterophoria (P = 0.014, significant at P < 0.05). The subnormal stereoacuity was positively correlated with the magnitude of refractive error of the eyes.Conclusion: This study underlines the significant impact of identification and correction of refractive errors and squints in school children. The measurement of stereoacuity will be of immense importance and must be included in the screening programs for children. [ABSTRACT FROM AUTHOR]

Background: To evaluate depth perception in Primary open angle glaucoma (POAG), glaucoma suspects compared to controls and to determine the association between depth perception and severity of glaucoma.Methods: This was a hospital based, comparative, cross-sectional study. The ethical clearance was taken from institutional review committee of Institute of Medicine [Reference no.399 (6-11) E2 077-078]. Agematched, equal number of participants in each group (N=20) were evaluated with both Titmus and Frisby stereoacuity tests to measure depth perception as stereopsis threshold in seconds of arc. The participants were selected using the purposive sampling technique.Results: There was no differences in age, sex, or best corrected visual acuity, intraocular pressure, central corneal thickness (CCT), found among the three groups (POAG, Glaucoma Suspects and Control) respectively. However, there was significant difference in cup disc ratio (CDR) between the groups. Equal number of male and female were there in each group, while in POAG group male to female ratio was 3:2. The mean stereoacuity threshold in control group was 53.5±23.23 seconds of arc with Titmus test and 38.75±18.83 seconds of arc with Frisby stereoacuity test. The difference in threshold was significant between control and glaucoma suspect with Titmus (t=1.991, p=0.05) and with Frisby (t=2.114, p=0.04). The difference was also significant in POAG group by Titmus (t=3.135, p=0.0033) and by Frisby (t=3.014, p=0.004). More so, with increasing severity of glaucoma, the mean threshold of stereopsis increased as seen with both Titmus and Frisby Tests (ANOVA, p < 0.001) CONCLUSION: Primary open angle glaucoma patients and glaucoma suspects, showed significant reduction in depth perception. Decreased stereoacuity was associated with greater glaucomatous visual field loss. [ABSTRACT FROM AUTHOR]

Background: Minimally invasive surgery (MIS) is not without impact on surgeons' neck/shoulder/head and eyes. However, the mechanisms for concurrent symptoms are not clear. This study aims to examine the effect of visual impairments on physical symptoms and surgical performance among surgeons performing simulated surgical tasks using two-dimensional (2D) and three-dimensional (3D) viewing modes. Methods: Gynaecologists with experience in laparoscopy performed four simulated surgical tasks in the 2D and 3D viewing modes. Visual parameters (accommodation, convergence and stereoacuity) were measured prior to commencement. Objective performance measures were derived from the laparoscopic tasks, and surgeons also self-reported their mental and physical workload using the NASA-TLX. In addition, perceived symptoms were measured using Visual Analogue Scales, the Simulator Sickness Questionnaire and the Computer Vision Syndrome Questionnaire. Results: Seventeen healthy gynaecologists participated in this study. There were significant relationships between visual impairments and both the perceived symptoms and surgical performance scores of MIS surgeons. Surgeons with a higher number of accommodation/convergence dysfunctions and/or poorer stereoacuity tended to have poorer objective performance scores on simulated surgical tasks in both viewing modes. NASA-TLX scores indicated that surgeons with poorer stereoacuity also perceived themselves to have been less successful at accomplishing tasks. However, these surgeons also reported less intense physical symptoms and simulator sickness. Conclusions: Surgeons' performance for the simulated surgical tasks correlated with visual functions, and it also impacted on the symptoms experienced. Regular screening of surgeons' vision and vision therapy may be required to decrease physical symptoms and improve surgical performance. [ABSTRACT FROM AUTHOR]