Improvement In Stereopsis Research Articles

Assessment of stereopsis in unilateral amblyopia subjects using syntonic phototherapy

ABSTRACT Introduction Amblyopia is two Snellen line difference between both eyes. Red filter therapy is a treatment option for amblyopia based on principle of syntonic phototherapy. The purpose of this study is to assess the stereopsis in amblyopic patient using syntonic phototherapy. Methods A Qusai experimental study was conducted from August 2021 to December 2021 at Madina Teaching Hospital Faisalabad. A total 30 subjects of both gender and ages ranging between 8 to 18 years were included through a non-probability purposive sampling technique. The sample was considered of 15 anisometropic amblyopes and 15 strabismic amblyope. Data was collected using a Performa and pre assessments of stereopsis by Titmus fly chart were recorded without red filter. Red filter glasses were prescribed for 4 week, post assessment data was recorded after 4 weeks. Data was analyzed by using Paired sample T test and Independent Sample T test in SPSS 20 software. Results After syntonic phototherapy significant improvement was seen, mean stereopsis was 48.00000 (p = 0.002) in anisometropic amblyopes while mean improvement of stereopsis 1.670.93333 (p = 0.00) in strabismic amblyopes. Anisometropic amblyopic patients showed significantly better improvement in stereopsis (p = 0.00) by syntonic phototherapy as compared to strabismic amblyopes. Conclusion Significant improvement was seen in stereopsis, while improvement was more significant in anisometropic amblyopes as compared to strabismic amblyopes. Children were obsessed with the red filter glasses while their parents found syntonic therapy simple plus facile and gave good results. So, eye care professionals must be aware of this new therapy and they should keep syntonic phototherapy in mind whenever they are dealing with amblyopic patients.

Outcome of pediatric cataract surgery including color vision, stereopsis, and cognition in a tertiary eye care center in India.

Pediatric cataract is an important cause of avoidable childhood blindness in India. Although there are studies on clinical features and visual acuity outcomes of pediatric cataract surgery, there are no studies that look into aspects of color vision, stereopsis, and cognitive functions in children with cataracts. Studying these parameters pre- and postsurgery will help us assess the overall components of visual function that are critical for the child's development. With this in mind, we aimed to study the clinical features, outcome of treatment, color vision, stereopsis, and cognitive functions in children with cataracts. Design: Hospital-based prospective descriptive study. Data of 68 children (0 < 18 years) were collected, on the clinical features, visual acuity, color vision, stereopsis, and social and intelligence quotient before and after surgery. Data analysis was performed using Graph Pad Prism software version 9.4.0 (673). Ninety eyes of 68 children (36-bilateral/32-unilateral) were operated. A total of 46 children were available at 6 months' follow-up (28 bilateral cataracts (46 eyes) and 18 unilateral cataracts). Nineteen (67.8%) of the bilateral, had a best corrected visual acuity of 6/6-6/18 in the better eye and nine (50%) of the unilateral had a visual acuity of 6/18-6/6 in the operated eye. Preoperatively, 61.5% of the children had a stereopsis of 100-600 arc-secs. Post-operatively, 84.4% of the children had a stereopsis in the range <50-600 arc-secs. All children had color vision deficiency. Preoperatively, 62% of the children had strong and moderate deficiency, whereas postoperatively, 66.6% had mild deficiency. We found negative correlation (r = -0.503) between social quotient and percentage of visual impairment indicating that when visual impairment increases social quotient decreases. The mean IQ preoperatively was 94.36 ± 2.98 and postoperatively 101.38 ± 2.77, with 95% confidence interval P value was statistically significant (P = 0.0001). This shows better and faster performance postoperatively. Majority of the children had improved visual acuity after surgery. This outcome can be extrapolated to the overall improvement in stereopsis, color vision, and higher cognitive functions.

Sensory Function of Children With Strabismus After Epiblepharon Surgery.

To investigate the effect of epiblepharon surgery on motor and sensory function in children with epiblepharon and concomitant strabismus. Among 564 patients who underwent epiblepharon correction surgery from May 2016 to April 2023, 45 children who were examined for strabismus were included in the study. Preoperative and postoperative visual acuity, refraction, and angle of deviation were analyzed. For those with significant angle of deviation, additional stereopsis, sensory fusion, and returning time were retrospectively investigated. The angle of deviation was examined by one examiner at distance and near. The mean age of 45 children (18 boys and 27 girls) was 6.8 ± 2.9 years. Fifteen had significant strabismus at the time of epiblepharon surgery. Visual acuity improved in both the total and strabismus groups. Improvement in stereopsis and fusion was also observed in the strabismus group. The angle of deviation showed no difference in both groups. Epiblepharon could affect ocular manifestations of strabismus as shown in this study. The authors suggest strabismus treatment be continued after epiblepharon surgery, with improved sensory function. Further evaluation with larger groups is needed in the future. [J Pediatr Ophthalmol Strabismus. 2024;61(4):257-261.].

Real-world evaluation of amblyopic patient characteristics, clinical outcomes, and treatment patterns using the IRIS Registry

To characterize the demographics, eye-related comorbidities, clinical characteristics, clinical outcomes, type of amblyopia tests used, and treatment patterns of a large cohort of pediatric, teenage, and adult amblyopic patients from the IRIS (Intelligent Research in Sight) Registry. In this retrospective electronic health record analysis, we analyzed 456,818 patients, of whom 197,583 (43.3%) were pediatric patients; 65,308 (14.3%), teenagers; and 193,927 (42.5%), adults. Baseline best-corrected visual acuity examination in both eyes was conducted within 90 days prior to index date. Three age cohorts were analyzed based on age at the index date: pediatric (3-12 years), teen (13-17 years), and adult (18-50 years). At index date, unilateral amblyopia was more common than bilateral amblyopia in all age cohorts (pediatric, 55% vs 45%; teen, 61% vs 39%; adult, 63% vs 37%). In unilateral amblyopic patients, severe amblyopia was more frequent in adults (21%) than in pediatric patients (12%) and teenagers (13%); in bilateral amblyopic patients, severity was comparable in pediatric patients and adults (4% severe in both). The greatest level of visual acuity improvement was demonstrated in pediatric patients with severe unilateral amblyopia at baseline. Pediatric patients showed significant improvement in stereopsis over time at years 1 (P = 0.000033) and 2 (P = 0.000039) at the population level (per χ2 test vs baseline). Our findings highlight the need for more efficacious amblyopia therapies in older, more severe patients with refractory disease.

Stereopsis following delayed strabismus surgery in early-onset strabismus.

Improved stereoacuity following delayed strabismus surgery is associated with long-term alignment of eyes and reduced severity of amblyopia. The objective of this study is to evaluate stereopsis following delayed strabismus surgery in early-onset strabismus. It is a hospital-based prospective, nonrandomized, interventional case study. Thirty patients with early-onset strabismus (before 3 years of age), presenting after 6 years of age were included. History taking and full orthoptic workup was done. Stereopsis was tested with Titmus Fly Chart test. The patients were treated surgically to correct strabismus and were followed up for 3 months. Quantitative parameters were compared between preoperative and postoperative follow-up at 3 months using McNemar test, Chi-square test, and independent t-test. Of the 21 patients who had gross stereopsis preoperatively, nine of them (42.86%) attained fine stereopsis at 3 months postoperatively (P = 0.003, McNemar test). Ten (33.33%) of 30 patients had amblyopia and three out of 30 patients (10%) had preoperative "nil" stereopsis. Of the patients who showed improvement (16 of 30 patients - 53.33%), most of the improvement was observed in (a) exodeviations (56.25%, n = 9), (b) earlier age of presentation-before 10 years of age (47.36%, n = 9). The benefits of surgical correction of early-onset strabismus include improvement in stereopsis. Therefore, even in an early-onset squint with a delayed presentation rehabilitation of stereopsis should be the goal of treatment.

Cortical Deficits are Correlated with Impaired Stereopsis in Patients with Strabismus

In this study, we explored the neural mechanism underlying impaired stereopsis and possible functional plasticity after strabismus surgery. We enrolled 18 stereo-deficient patients with intermittent exotropia before and after surgery, along with 18 healthy controls. Functional magnetic resonance imaging data were collected when participants viewed three-dimensional stimuli. Compared with controls, preoperative patients showed hypoactivation in higher-level dorsal (visual and parietal) areas and ventral visual areas. Pre- and postoperative activation did not significantly differ in patients overall; patients with improved stereopsis showed stronger postoperative activation than preoperative activation in the right V3A and left intraparietal sulcus. Worse stereopsis and fusional control were correlated with preoperative hypoactivation, suggesting that cortical deficits along the two streams might reflect impaired stereopsis in intermittent exotropia. The correlation between improved stereopsis and activation in the right V3A after surgery indicates that functional plasticity may underlie the improvement of stereopsis. Thus, additional postoperative strategies are needed to promote functional plasticity and enhance the recovery of stereopsis.

Slanted recession on bilateral lateral rectus for the treatment of intermittent Exotropia with convergence insufficiency

PurposeTo evaluate the efficacy and safety of slanted bilateral lateral rectus recession (S-BLRc) for the treatment of convergence insufficiency-type intermittent exotropia (CI-IXT) in children and to probe the relationship of the slanted amount and surgical outcomes.MethodsRetrospective study. Fifty-eight patients with CI-IXT, aged 4 to 10 years old, underwent S-BLRc procedures. According to the different slanted amount between the upper and lower poles of lateral rectus, all the patients were grouped: Group A (slanting 1 mm, n = 22), Group B (slanting 1.5 mm, n = 18) and Group C (slanting 2 mm, n = 18). The successful surgical outcome was defined as deviation in the primary position ranging from exotropia< 8△ to esotropia< 5△ both at near and at distant as well as the near-distance difference (NDD) < 5△. We analyzed and compared the preoperative and postoperative data including deviations both at near and at distance, NDD, objective torsion, horizontal deviation at up and down gaze, lateral incomitance, binocular vision and surgical success rate among three groups.ResultsThe average deviations were significantly decreased from − 37.1△ ± 4.2△ (−,exotropia) to − 1.4△ ± 4.6△ at near (P < 0.05) and from − 25.8△ ± 3.7△ to − 0.1 ± 4.1△ at distance (P < 0.05). The postoperative NDD on average was significantly reduced from 10.0△ to 1.8△ in Group A (P < 0.05), from 11.2△ to 0.8△ in Group B (P < 0.05) and from 13.3△ to 0.9△ in Group C (P < 0.05). There was a significant difference in the mean corrections of NDD among the three groups (8.2△ in group A, 10.3△ in group B and 12.4△ in group C respectively, P < 0,05). All the patients attained various improvement of stereopsis after surgery. None had torsional diplopia, A-V pattern and lateral incomitance after strabismic surgery. Totally, the surgical success rate was 89.7% in our series at the 6- to 8-month follow-up.ConclusionsSlanted bilateral lateral rectus recession is an effective and safe procedure for the treatment of CI-IXT in children. S-BLRc can successfully collapse exotropia both at distance and at near, decrease NDD and benefit to gain binocular vision. The correction of NDD was associated with the slanted amount.

Binocular versus standard occlusion or blurring treatment for unilateral amblyopia in children aged three to eight years.

Binocular versus standard occlusion or blurring treatment for unilateral amblyopia in children aged three to eight years.

Factors Determining Improvement in Stereopsis and Binocularity After Good Postoperative Alignment in Patients With Childhood-Onset Strabismus.

Introduction: The purpose of the present study was to determine the factors that affect the outcome of strabismus surgery in terms of improvement in stereopsis and binocularity.Methods: Data were collected prospectively from patients with childhood-onset, concomitant, constant strabismus greater than 30 prism diopters (PD) with postoperative alignment within 10 PD. Pre- and postoperative stereopsis and binocularity testing were performed using the Titmus fly test, random dot test, Bagolini striated glass test, and Worth four dot test at one, four, and 12 weeks postoperatively.Results: A total of 73 patients (55% males and 45% females) who underwent surgery at our center were studied. The mean age at the time of surgery was 16 ± 7.7 years (range: 5-35 years). We found that factors such as age of strabismus onset, type of deviation, and amblyopia had a statistically significant influence on the postoperative surgical outcome. A statistically insignificant relationship was noted with gender, refractive error, and duration of strabismus. Patients who had strabismus after six months of age noticed a significant improvement in stereopsis (p-value = 0.000) than those who had strabismus before six months of age (p-value = 0.660). Further, there was a statistically significant improvement in patients having exotropia (p-value = 0.018) or combined horizontal and vertical deviations (p-value = 0.000), but there was no significant improvement in patients with esotropia (p-value = 0.180). Moreover, non-amblyopes had a significantly better postoperative stereopsis than amblyopes (p-value = 0.006). Although there was no association between preoperative deviation and improvement in stereopsis (p-value = 0.081), patients having preoperative deviation in the range of 31-45 PD had a statistically significant improvement in stereopsis (p-value = 0.000). There was no significant difference between postoperative residual deviation and final stereopsis (p-value > 0.05). All the results were the same for both the Titmus test and the random dot test. Binocular fusion was observed in 34 subjects, and uniocular suppression was noted in 38 subjects preoperatively. It was observed that only one patient gained binocular single vision postoperatively.Conclusion: The presence of amblyopia, esotropia, early onset of strabismus (within six months of age), and a larger preoperative deviation (>45 PD) were associated with poorer stereopsis. In patients with horizontal strabismus, the coexistence of vertical deviation had a positive impact on the postoperative stereopsis. Gender, refractive error, and duration of strabismus did not influence the final stereopsis in our study.

Binocular therapy as primary intervention in adults with anisometropic amblyopia.

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.

Role of improved distance and near visual acuity with low vision aids to enhance stereopsis in retinal diseases.

Purpose:The purpose of this study was to examine role of improved distance and near best-corrected visual acuity (DBCVA and NBCVA) with use of magnification devices to enhance stereopsis in low vision (LV) subjects having retinal diseases.Methods:In a cross-sectional observational study without control, 84 subjects having LV due to retinal diseases were examined for an improvement of BCVA with use of magnifying low vision aids (LVAs) (2X for DBCVA and 3X for NBCVA). The stereopsis scores on titmus fly test were recorded with near refractive correction “on” and then with 3X magnification. The improvement in stereopsis for distance was however estimated through statistical correlation values.Results:The DBCVA (P < 0.001), NBCVA (P < 0.001) and stereopsis (P < 0.001) improved statistically significantly (SS) following magnifying LVA. There was no correlation between pre-LVA stereopsis and pre-LVA DBCVA (r = 0.059; P = 0.444;NSS) and post-LVA DBCVA (r = 0.054; P = 0.487;NSS); and no correlation between post-LVA stereopsis and pre-LVA DBCVA (r = 0.042; P = 0.592;NSS) and post-LVA DBCVA (r = 0.08; P = 0.920;NSS). There was no correlation between pre-LVA stereopsis and pre-LVA NBCVA (r = 0.044; P = 0.572;NSS) and no correlation between post-LVA stereopsis and pre-LVA NBCVA (r = 0.108; P = 0.165;NSS). But positive correlation between pre-LVA stereopsis and post-LVA NBCVA (r = 0.347; P < 0.001) and between post-LVA stereopsis and post-LVA NBCVA (r = 0.445; P < 0.001) was SS.Conclusion:The use of magnification as LVA improves both the BCVA and stereopsis. The increase in DBCVA with LVA improves the stereopsis for distance though it may not be SS while improvement in NBCVA with LVA enhances stereopsis for near objects in SS manner.

Predictive factors of stereopsis outcomes following strabismus surgery.

Purpose:To determine the predictive factors of post-operative stereopsis in patients with strabismus.Method:In this retrospective study, records of patients who received surgical treatment for strabismus were reviewed. All types of strabismus were included. Pre- and post-treatment stereoacuity were measured using the Titmus Stereo Fly test, and predictive factors of stereopsis were evaluated.Results:A total of 194 patients (132 females and 62 males) with a mean age of 14.8 ± 8.4 years were included. There was a statistically significant improvement in stereopsis following surgery (p value < 0.001). Patients with a higher amount of deviation at baseline had poorer stereopsis on the final examination (p value < 0.001). Stereopsis improvement was more prominent in the pure horizontal strabismus group, compared to combined horizontal and vertical deviations. Baseline and the final stereopsis were higher in the “exotropia” group as compared to the “esotropia” group (p value = 0.003 and 0.0155, respectively); however, the within group change of stereopsis was not significantly different between these two groups (p value = 0.144). Post surgical residual deviation was associated with a poorer stereopsis (p value = 0.002, r = 0.251). A longer duration of strabismus before surgery was associated with poorer final stereopsis levels (p value = 0.026). The presence of amblyopia before surgery was associated with poorer stereopsis on last examination (p value < 0.001 for both correlations).Conclusion:Based on the result of this study, final stereopsis after strabismus surgery could be affected by the type, duration, and the amount of deviation before surgery, amblyopia, and post operative ocular deviation.

Stereopsis deficiency treatment using virtual reality games in exotropic candidate for firefighter

Background: Impaired stereopsis very often limits career options for patients with binocular vision disorders. Eyesight requirements for some occupations like police officers and firefighters usually include perfect visual acuity. In Poland, candidates for these professions must also demonstrate perfect stereopsis. The presented case study aims to demonstrate that vision therapy (VT1) mixed with new technologies may be an effective treatment for young adults who do not meet the chosen occupation's visual requirements.&#x0D; Case report: A case of a young man diagnosed with intermittent exotropia and poor stereopsis is discussed. Poor stereopsis did not allow him to pass the ophthalmological qualification tests to the fire academy. Vision therapy was implemented to improve stereopsis. The case report presents the patient’s treatment implemented within 4 years. The patient started with prismatic correction, then received the office-based VT with home reinforcement. The improvement in fusional vergence and the control of deviation was observed. Nevertheless, the patient was still stereo-deficient. 3 years later, Binocular Vision Therapy in Virtual Reality (BVTVR2) was recommended. The patient received home-based therapy for 16 weeks (60 minutes per day), which has resulted in significant improvement of stereopsis. As a result, he finally met the visual requirements to become a firefighter.&#x0D; Conclusion: BVTVR appears to be a promising rehabilitation method for patients with poor stereopsis. Three-dimensional anti-suppression therapy and dynamic, real-life stereopsis training seem to be a more effective treatment of poor stereopsis compared to standard VT techniques.

Looking beyond occlusion: A novel perspective for amblyopia treatment.

Purpose:The aim of this study was to evaluate the efficacy of Orthoptek (Magnocellular Stimulator OMS; Carditek Pvt. Ltd., Bangalore) as a treatment modality for amblyopia and strabismus.Methods:Thirty-five patients with amblyopia of any type, reduced vision in one or both eyes with no binocular vision and or poor stereopsis were included in the study. All patients underwent a minimum of 10 sessions of therapy with each session lasting for a cumulative period of 60 min. At the end of the 10th session, patients were evaluated for improvement in visual acuity, stereopsis, Binocular single vision and amount of strabismus, if any.Results:The mean logMAR corrected distance visual acuity improved from 0.31 ± 0.34 and 0.32 ± 0.44 to 0.08 ± 0.12 and 0.07 ± 0.12 posttreatment in the right eye and left eye, respectively. Following therapy, 34 (97%) patients showed improvement in stereopsis, orthophoria was noticed in 28 (80%), and binocular single vision was noted in 33 (94%). All patients were followed up for 1 year with maintenance therapy and none showed any regression.Conclusion:We believe that top–down impulses and the role of the attention area in the parietal cortex have not been studied well enough in the treatment of amblyopia. Our device addresses these issues and corrects the visual deficits in amblyopia. However, the study needs validation of this pilot study from independent centers. The same will be done at some stage

The Effects of Nonsurgical Treatment in Intermittent Exotropia by Meta-Analysis

Purpose: To understand research trends in domestic and foreign primary studies related to the effect of nonsurgical treatment of intermittent exotropia by meta-analysis, and to suggest clinical and theoretical implications based on the direction and magnitude of the nonsurgical treatment effect for intermittent exotropia. Methods: Of the thesis related to the effect of nonsurgical treatment of intermittent exotropia published in domestic and international journals and dissertations from 1990 to 2015, 15 papers selected from the inclusion and exclusion criteria were analyzed for meta-analysis. The effect size and variance of individual primary studies and overall effect size were calculated and then verified homogeneity. Also, the difference of effective size in different treatment methods by sub-group was verified. The treatment method, type of strabismus and age of treatment time were selected as variables to be considered for conducting the non-surgical treatment of intermittent exotropia, and the effect of each variable on treatment of intermittent exotropia were analyzed. Results: The overall effect size of non-surgical treatment of intermittent exotropia was -0.715. The order of effect size of the treatment method was orthoptics; -1.753, mixed treatment; -1.747, correction of refractive error; -1.295, minus lens overcorrection; -0.500 and then occlusion therapy; -0.281. The order of effect size of strabismus types was divergent excess; -2.111, convergence insufficiency; -1.171, and then basic; -1.220. The order of effect size of age groups was 13∼19 yrs.; -2.029, 7∼13 yrs.; -1.057, under 4 yrs.; -0.751 and then 4∼7 yrs.; -0.379. Conclusions: It is considered that the effect size in this study was analysed quantitatively the improving effect such as the decrease of deviation or the improvement of stereopsis and so on with the nonsurgical treatment in patients with intermittent exotropia, and the objective relevance of the nonsurgical treatment was suggested by these results.

Surgical success and lateral incomitance following three-muscle surgery for large-angle horizontal strabismus

To evaluate motor alignment, motility, and sensorial outcomes of simultaneous three-muscle surgery for large-angle horizontal strabismus, with special attention to lateral incomitance and long-term success. The medical records of consecutive patients with large-angle deviations (≥30Δ) who underwent simultaneous surgery on three horizontal muscles to correct esotropia or exotropia were reviewed retrospectively. Successful motor alignment was defined as residual deviation of ≤10Δ and consecutive deviation in primary position of ≤4Δ, with no induced lateral incomitance >5Δ between lateral gazes. Sensory success was defined as an improvement in stereopsis of ≥2 octaves. Surgical procedures included a combination of recessions and resections/plications depending on surgeon preference. The majority of cases were two-muscle recessions combined with one-muscle resection or plication. A total of 19 patients with exotropia and 9 patients with esotropia were included. In the esotropic group, the mean age at surgery was 48±15years and the mean preoperative deviation improved from 45.6Δ ± 11.9Δ to 1.5Δ ± 1.6Δ (P<0.001); there was no undercorrection, recurrence or overcorrection. In the exotropic group, the mean age at surgery was 44±25years, and the mean preoperative deviation improved from 44.1Δ ± 8.7Δ to 5.8Δ ± 9.6Δ (P<0.001), recurrence occurred in 2 (22%). Overall motor success at distance was 85%, with 1 (3.8%) unsuccessful patient due to induced incomitance. Sensory success was 44% for esotropia and 31% for exotropia. No patient lost stereopsis. Patients undergoing three-muscle surgery for horizontal strabismus had good motor outcomes with low incidence of induced lateral incomitance. Motor and sensorial outcomes for esotropia were very stable.

A Flicker Therapy for the Treatment of Amblyopia

Background: Standard clinical treatment methods for amblyopia penalize the nonamblyopic eye, with subsequent compliance problems, and do not address the associated binocular vision abnormality. The purpose of this study is to evaluate a novel approach to amblyopia treatment that uses rapid alternating occlusion and flicker and aims to improve monocular and binocular vision. Methods: A pre-post (12 weeks) interventional study with historical data control. Children with anisometropic amblyopia (ages 5 to 17 years, n=23) were enrolled by consecutive sample. Subjects wore Eyetronix Flicker Glass, shutter glasses with liquid crystal lenses that rapidly alternated occlusion at a programmable frequency, for 1-2 hours daily while performing a near task of their choice, e.g., homework, computer. Outcome measures were: (1) bestcorrected LogMAR visual acuity (BCVA) and (2) Random Dot 2 stereopsis. Results: After 12 weeks of therapy, 96% (n=22) of the children treated improved BCVA in the amblyopic eye (p&lt;0.001) - over 26% (n=6) improved 2 LogMAR lines or more (fellow eye BCVA did not change) - and 89% of the children with reliable data (n=18) improved global stereopsis. Conclusions: This relatively passive therapy has shown encouraging results as a potential treatment for amblyopia. The improvement in BCVA is comparable to previous studies that used traditional amblyopia therapies. The improvement in stereopsis suggests that the therapy promotes binocular vision. Notably, BCVA and stereopsis improved across all ages and in subjects who had previously plateaued with conventional therapies. Randomized masked and controlled studies are the next step to further quantify the clinical efficacy of this therapy.

Changes in stereopsis after photorefractive keratectomy

To evaluate the effects of photorefractive keratectomy (PRK) on the stereopsis of myopic and hyperopic patients. Farabi Eye Hospital, Tehran, Iran. Prospective case series. This study included patients having PRK to achieve emmetropia. The patients were divided into the following 3 groups: low myopia (<-6.0 diopters [D]), high myopia (>-6.0 D), and hyperopia (<+4.0 D). Near stereoacuity was measured using the Randot test under photopic conditions (with corrective glasses) at 40cm preoperatively (with corrective glasses) and 1, 3, and 12months postoperatively. Repeated-measure analysis of variance was used to assess changes in stereopsis over time in the 3 groups. Each group comprised 60 patients. The mean preoperative stereoacuity was 121.16seconds of arc (arcsec)±149.92 (SD), improving to 83.66±75.84 arcsec 1month postoperatively and 80.66±64.31 arcsec at 3months (both P<.001). It remained unchanged (83.33±75.01 arcsec) at 12months (P=.610). Patients with high myopia had the greatest improvement in stereopsis after PRK compared with low myopic and hyperopic patients (P<.001). The improvement in stereoacuity was significantly higher in the severe anisometropic group; the lowest improvement was in the group without anisometropia. Photorefractive keratectomy could result in an improvement in stereopsis. Patients with high myopia benefitted most from PRK in terms of improvement in stereopsis. None of the authors has a financial or proprietary interest in any material or method mentioned.

Predictive Factors Affecting Long-Term Outcome of Unilateral Lateral Rectus Recession.

BackgroundThere are few long-term outcome reports of unilateral lateral rectus (LR) recession for exotropia including a large number of subjects. Previous reports on unilateral LR recession commonly show extremely low rates of initial overcorrection and large exodrifts after surgery suggesting that the surgical dose may be increased. However, little is known of the long-term outcome of a large unilateral LR recession for exotropia.ObjectivesTo determine long-term outcomes and predictive factors of recurrence after a large unilateral LR recession in patients with exotropia.Data ExtractionRetrospective analysis was performed on 92 patients aged 3 to 17 years who underwent 10 mm unilateral LR recession for exotropia of ≤ 25 prism diopters (Δ) with prism and alternate cover testing and were followed up for more than 2 years after surgery. Final success rates within 10Δ of exophoria/tropia and 5Δ of esophoria/tropia at distance in the primary position, improvement in stereopsis and the predictive factors for recurrence were evaluated.ResultsAt 24 months after surgery, 54% of patients had ocular alignment meeting the defined criteria of success, 45% had recurrence and 1% had overcorrection. After a mean follow-up of 39 months, 36% showed success, 63% showed recurrence and 1% resulted in overcorrection. The average time of recurrence was 23.4±14.7 months (range, 1–60 months) and the rate of recurrence per person-year was 23% after unilateral LR recession. Predictive factors of recurrence were a larger preoperative near angle of deviation (>16Δ) and larger initial postoperative exodeviation (>5Δ) at distance.ConclusionsLong-term outcome of unilateral LR recession for exotropia showed low success rates with high recurrence, thus should be reserved for patients with a small preoperative near angle of exodeviation.

Binocular versus standard occlusion or blurring treatment for unilateral amblyopia in children aged three to eight years.

Current treatments for amblyopia in children, occlusion and pharmacological blurring, have had limited success, with less than two-thirds of children achieving good visual acuity of at least 0.20 logMAR in the amblyopic eye, limited improvement of stereopsis, and poor compliance. A new treatment approach, based on the dichoptic presentation of movies or computer games (images presented separately to each eye), may yield better results, as it aims to balance the input of visual information from each eye to the brain. Compliance may also improve with these more child-friendly treatment procedures. To determine whether binocular treatments in children aged three to eight years with unilateral amblyopia result in better visual outcomes than conventional occlusion or pharmacological blurring treatment. We searched the Cochrane Eyes and Vision Group Trials Register (last date of searches: 14 April 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to April 2015), EMBASE (January 1980 to April 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. Two review authors independently screened the results of the search in order to identify studies that met the inclusion criteria of the review: randomised controlled trials (RCTs) that enrolled participants between the ages of three and eight years old with unilateral amblyopia, defined as best-corrected visual acuity (BCVA) worse than 0.200 logMAR in the amblyopic eye, and BCVA 0.200 logMAR or better in the fellow eye, in the presence of an amblyogenic risk factor such as anisometropia, strabismus, or both. Prior to enrolment, participants were to have undergone a cycloplegic refraction and comprehensive ophthalmic examination including fundal examination. In addition, participants had to have completed a period of optical treatment, if indicated, and BCVA in the amblyopic eye had to remain unchanged on two consecutive assessments despite reportedly good compliance with glasses wearing. Participants were not to have received any treatment other than optical treatment prior to enrolment. We planned to include any type of binocular viewing intervention; these could be delivered on different devices including computer monitors viewed with LCD shutter glasses or hand-held screens including mobile phone screens with lenticular prism overlay. Control groups were to have received standard amblyopia treatment; this could include occlusion or pharmacological blurring of the better-seeing eye. We planned to include full-time (all waking hours) and part-time (between 1 and 12 hours a day) occlusion regimens. We planned to use standard methodological procedures expected by The Cochrane Collaboration. We had planned to meta-analyse the primary outcome, that is mean distance BCVA in the amblyopic eye at 12 months after the cessation of treatment. We could identify no RCTs in this subject area. Further research is required to allow decisions about implementation of binocular treatments for amblyopia in clinical practice. Currently there are no clinical trials offering standardised evidence of the safety and effectiveness of binocular treatments, but results from non-controlled cohort studies are encouraging. Future research should be conducted in the form of RCTs, using acknowledged methods of visual acuity and stereoacuity assessment with known reproducibility. Other important outcome measures include outcomes reported by users, compliance with treatment, and recurrence of amblyopia after cessation of treatment.