Interventions for convergence insufficiency: a network meta-analysis.

BACKGROUND: Convergence insufficiency is a common binocular vision disorder in which the eyes have a strong tendency to drift outward (exophoria) with difficulty turning the eyes inward when reading or doing close work. OBJECTIVES: To assess the comparative effectiveness and relative ranking of non-surgical interventions for convergence insufficiency through a systematic review and network meta-analysis (NMA). SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, PubMed and three trials registers up to 20 September 2019. SELECTION CRITERIA: We included randomized controlled trials (RCTs) examining any form of non-surgical intervention versus placebo, no treatment, sham treatment, or other non-surgical interventions. Participants were children and adults with symptomatic convergence insufficiency. DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methodology. We performed NMAs separately for children and adults. MAIN RESULTS: We included 12 trials (six in children and six in adults) with a total of 1289 participants. Trials evaluated seven interventions: 1) office‐based vergence/accommodative therapy with home reinforcement; 2) home‐based pencil/target push‐ups; 3) home‐based computer vergence/accommodative therapy; 4) office‐based vergence/accommodative therapy alone; 5) placebo vergence/accommodative therapy or other placebo intervention; 6) prism reading glasses; and 7) placebo reading glasses. Six RCTs in the pediatric population randomized 968 participants. Of these, the Convergence Insufficiency Treatment Trial (CITT) Investigator Group completed four RCTs with 737 participants. All four CITT RCTs were rated at low risk of bias. Diagnostic criteria and outcome measures were identical or similar among these trials. The four CITT RCTs contributed data to the pediatric NMA, incorporating interventions 1, 2, 3 and 5. When treatment success was defined by a composite outcome requiring both clinical measures of convergence to be normal, and also show a pre‐specified magnitude of improvement, we found high‐certainty evidence that office‐based vergence/accommodative therapy with home reinforcement increases the chance of a successful outcome, compared with home‐based computer vergence/accommodative therapy (risk ratio (RR) 1.96, 95% confidence interval (CI) 1.32 to 2.94), home‐based pencil/target push‐ups (RR 2.86, 95% CI 1.82 to 4.35); and placebo (RR 3.04, 95% CI 2.32 to 3.98). However, there may be no evidence of any treatment difference between home‐based computer vergence/accommodative therapy and home‐based pencil/target push‐ups (RR 1.44, 95% CI 0.93 to 2.24; low‐certainty evidence), or between either of the two home‐based therapies and placebo therapy, for the outcome of treatment success. When treatment success was defined as the composite convergence and symptom success outcome, we found moderate‐certainty evidence that participants who received office‐based vergence/accommodative therapy with home reinforcement were 5.12 (95% CI 2.01 to 13.07) times more likely to achieve treatment success than those who received placebo therapy. We found low‐certainty evidence that participants who received office‐based vergence/accommodative therapy with home reinforcement might be 4.41 (95% CI 1.26 to 15.38) times more likely to achieve treatment success than those who received home‐based pencil push‐ups, and 4.65 (95% CI 1.23 to 17.54) times more likely than those who received home‐based computer vergence/accommodative therapy. There was no evidence of any treatment difference between home‐based pencil push‐ups and home‐based computer vergence/accommodative therapy, or between either of the two home‐based therapies and placebo therapy. One RCT evaluated the effectiveness of base‐in prism reading glasses in children. When base‐in prism reading glasses were compared with placebo reading glasses, investigators found no evidence of a difference in the three outcome measures of near point convergence (NPC), positive fusional vergence (PFV), or symptom scores measured by the Convergence Insufficiency Symptom Survey (CISS). Six RCTs in the adult population randomized 321 participants. We rated only one RCT at low risk of bias. Because not all studies of adults included composite success data, we could not conduct NMAs for treatment success. We thus were limited to comparing the mean difference (MD) between interventions for improving NPC, PFV, and CISS scores individually using data from three RCTs (107 participants; interventions 1, 2, 4 and 5). Compared with placebo treatment, office‐based vergence accommodative therapy was relatively more effective in improving PFV (MD 16.73, 95% CI 6.96 to 26.60), but there was no evidence of a difference for NPC or the CISS score. There was no evidence of difference for any other comparisons for any outcomes. One trial evaluated base‐in prism glasses prescribed for near‐work activities and found that the prism glasses group had fewer symptoms compared with the placebo glasses group at three months (MD ‐8.9, 95% CI ‐11.6 to ‐6.3). The trial found no evidence of a difference with this intervention in NPC or PFV. No adverse effects related to study treatments were reported for any of the included studies. Excellent adherence was reported for office‐based vergence/accommodative therapy (96.6% or higher) in two trials. Reported adherence with home‐based therapy was less consistent, with one study reporting decreasing adherence over time (weeks 7 to 12) and lower completion rates with home‐based pencil/target push‐ups. AUTHORS' CONCLUSIONS: Current research suggests that office-based vergence/accommodative therapy with home reinforcement is more effective than home-based pencil/target push-ups or home-based computer vergence/accommodative therapy for children. In adults, evidence of the effectiveness of various non-surgical interventions is less clear

Diagnostic accuracy of indigenously developed computer-based binocular vision assessment

CONTEXT: The increased prevalence of nonstrabismic binocular vision anomalies (NSBVA) has given rise to the need for cost-effective screening and diagnostic tools. AIMS: The aim of the study is to assess the efficacy of an indigenously developed computer-based binocular vision assessment software (Train Your Eyes®) in screening NSBVA. SUBJECTS AND METHODS: Subjects who visited the binocular vision clinic of a tertiary eye care center with asthenopic symptoms between January 2019 and January 2020 were included in the study. Patients with other ocular comorbidities and stereopsis poorer than 500 arc seconds were excluded. All subjects underwent a comprehensive eye examination followed by binocular vision assessment using both the manual and computer-based methods. STATISTICAL ANALYSIS USED: Receiver operating characteristic (ROC) curves were utilized to choose the cut-off points that maximize the sensitivity and specificity. RESULTS: The mean (standard deviation) age of 88 subjects was 22 (4.5) years with 34 males. Based on the conventional manual assessment, 71 (81%) were diagnosed to have NSBVA and 17 (19%) had normal binocular vision. Based on the ROC analysis, the following cut-off points are proposed: 14 prism diopter (PD) for near positive fusional vergence amplitudes, 4.5 PD for near negative fusional vergence amplitudes, 4.5 cycles per minute (cpm) for binocular accommodative facility, and 3.5 cpm for monocular accommodative facility. All the binocular vision parameters demonstrated statistical significance in the ROC analysis (P < 0.05). CONCLUSIONS: The software-based screening tool was found to be highly sensitive in identifying NSBVA and thus could be used as a potential screening tool in the clinic and community

Parental perception of facilitators and barriers to activity and participation in an integrated tele-rehabilitation model for children with cerebral visual impairment in South India - A virtual focus group discussion study

PURPOSE: This study utilized virtual focus group discussions to document the facilitators and barriers reported by the parents as part of the tele-rehabilitation service delivery model in India. METHODS: This study included 17 participants who were enrolled into the Tele-rehabilitation program (16 mothers, 1 father) and the virtual focus group discussion (V-FGD) were conducted through a WhatsApp video call. Three V-FGDs were conducted involving two moderators and a note taker. The V-FGD, focused at extracting the perceptions of parents pertaining to facilitators, barriers and coping mechanisms to barriers related to the tele-rehabilitation model. RESULTS: Thematic analysis resulted in four themes for barriers that included: family and support, time, parent and care taker, child and place of living related; facilitators reported included: continuous monitoring, accessibility to professional services, provision of resource materials and parental empowerment. Themes "family and support" and "child" were most reported by parents with children >3 years and ≤3 years respectively. Finally, the barriers and facilitators were aligned with the chapters and codes of International Classification of Functioning, children and youth version (ICF-CY) environment and personal factors. CONCLUSION: This V-FGD highlights the importance of parental-centred and structured Tele-rehabilitation among children with CVI in India. The outcome of this study opens avenues for creating effective intervention

Changes in stimulus and response AC/A ratio with vision therapy in Convergence Insufficiency

Purpose: To evaluate the changes in the stimulus and response Accommodative Convergence to Accommodation (AC/A) ratio following vision therapy (VT) in Convergence Insufficiency (CI). Methods: Stimulus and response AC/A ratio were measured on twenty five CI participants, pre and post 10 sessions of VT. Stimulus AC/A ratio was measured using the gradient method and response AC/A ratio was calculated using modified Thorington technique with accommodative responses measured using WAM-5500 open-field autorefractor. The gradient stimulus and response AC/A cross-link ratios were compared with thirty age matched controls. Results: Mean age of the CI and control participants were 23.3 ± 5.2 years and 22.7 ± 4.2 years, respectively. The mean stimulus and response AC/A ratio for CI pre therapy was 2.2 ± 0.72 and 6.3 ± 2.0 PD/D that changed to 4.2 ± 0.9 and 8.28 ± 3.31 PD/D respectively post vision therapy and these changes were statistically significant (paired t-test; p < 0.001). The mean stimulus and response AC/A ratio for controls was 3.1 ± 0.81 and 8.95 ± 2.5 PD/D respectively. Conclusions: Stimulus and response AC/A ratio increased following VT, accompanied by clinically significant changes in vergence and accommodation parameters in subjects with convergence insufficiency. This represents the plasticity of the AC/A crosslink ratios that could be achieved with vision therapy in CI

Efficacy of vision therapy in children with learning disability and associated binocular vision anomalies

Purpose: To report the frequency of binocular vision (BV) anomalies in children with specific learning disorders (SLD) and to assess the efficacy of vision therapy (VT) in children with a non-strabismic binocular vision anomaly (NSBVA). Methods: The study was carried out at a centre for learning disability (LD). Comprehensive eye examination and binocular vision assessment was carried out for 94 children (mean (SD) age: 15 (2.2) years) diagnosed with specific learning disorder. BV assessment was done for children with best corrected visual acuity of ≥6/9 – N6, cooperative for examination and free from any ocular pathology. For children with a diagnosis of NSBVA (n = 46), 24 children were randomized to VT and no intervention was provided to the other 22 children who served as experimental controls. At the end of 10 sessions of vision therapy, BV assessment was performed for both the intervention and non-intervention groups. Results: Binocular vision anomalies were found in 59 children (62.8%) among which 22% (n = 13) had strabismic binocular vision anomalies (SBVA) and 78% (n = 46) had a NSBVA. Accommodative infacility (AIF) was the commonest of the NSBVA and found in 67%, followed by convergence insufficiency (CI) in 25%. Post-vision therapy, the intervention group showed significant improvement in all the BV parameters (Wilcoxon signed rank test, p < 0.05) except negative fusional vergence. Conclusion: Children with specific learning disorders have a high frequency of binocular vision disorders and vision therapy plays a significant role in improving the BV parameters. Children with SLD should be screened for BV anomalies as it could potentially be an added hindrance to the reading difficulty in this special population

Parental perception of facilitators and barriers to activity and participation in an integrated tele-rehabilitation model for children with cerebral visual impairment in South India – A virtual focus group discussion study

Purpose: This study utilized virtual focus group discussions to document the facilitators and barriers reported by the parents as part of the tele-rehabilitation service delivery model in India. Methods: This study included 17 participants who were enrolled into the Tele-rehabilitation program (16 mothers, 1 father) and the virtual focus group discussion (V-FGD) were conducted through a WhatsApp video call. Three V-FGDs were conducted involving two moderators and a note taker. The V-FGD, focused at extracting the perceptions of parents pertaining to facilitators, barriers and coping mechanisms to barriers related to the tele-rehabilitation model. Results: Thematic analysis resulted in four themes for barriers that included: family and support, time, parent and care taker, child and place of living related; facilitators reported included: continuous monitoring, accessibility to professional services, provision of resource materials and parental empowerment. Themes “family and support” and “child” were most reported by parents with children >3 years and ≤3 years respectively. Finally, the barriers and facilitators were aligned with the chapters and codes of International Classification of Functioning, children and youth version (ICF-CY) environment and personal factors. Conclusion: This V-FGD highlights the importance of parental-centred and structured Tele-rehabilitation among children with CVI in India. The outcome of this study opens avenues for creating effective intervention

Natural history of idiopathic abducens nerve paresis in a young adult

The natural history of idiopathic abducens nerve paresis and the role of conservative management such as vision training during the recovery process is not well documented in the literature to the best of our knowledge. This case report presents the natural recovery process of idiopathic abducens nerve paresis in a young adult and the role of vision therapy in the recovery process