Study report from outside of India, IRAN:

Abstract

Purpose

The aim was to determine the prevalence of convergence insufficiency and its relationship with age, gender and refractive error in a population-based study.

Methods

In this cross-sectional study, all residents over one year old in Mashhad city, in the north east of Iran, were sampled through random stratified cluster sampling. After selecting samples and their participation in the study, they all had eye examinations including the measurement of visual acuity, refraction, binocular vision assessment, including cover test, measurement of near point of convergence and fusional vergences and finally, slitlamp biomicroscopy.

Results

Of the 4,453 selected people, 3,132 participated in the study and finally, analyses were done with data from 2,219 individuals. The mean age of the participants was 30.5 ± 14.0 years (range: 10 to 69). The prevalence of convergence insufficiency in this study was 5.51 per cent (range: 4.51 to 6.52): 4.78 per cent (range: 3.11 to 6.45) in males and 5.86 per cent (range: 4.60 to 7.11) in females (p = 0.276). Convergence insufficiency prevalence in different age groups showed no significant linear trend; however, a significant increase was observed after the age of 60 years. The prevalence of myopia, emmetropia and hyperopia was respectively 12.1, 56.9 and 31 per cent in participants with convergence insufficiency and 15.9, 54.4 and 29.6 per cent in those without convergence insufficiency (p = 0.537). Multiple logistic regression models revealed no significant relationship between the prevalence of convergence insufficiency and age, gender or refractive errors.

Conclusion

This study showed that the overall prevalence of convergence insufficiency in the Iranian population was 5.46 per cent, which is lower than that in the majority of previous studies. Convergence insufficiency prevalence had no significant change with age up to the age of 60 years but increased significantly after 60 years.

http://onlinelibrary.wiley.com/doi/10.1111/cxo.12522/full

Study report from Bangalore:

http://jmrh.chitkara.edu.in/pdfs/03_JMRH_Diwakar.pdf

Fellowship in Vision Therapy at Sankara Nethralaya:

http://www.thesnacademy.ac.in/fellowship-vision-therapy.html

Abstract
Population-based studies on the prevalence of non-strabismic anomalies of binocular vision in ethnic Indians are more than two decades old. Based on indigenous normative data, the BAND (Binocular Vision Anomalies and Normative Data) study aims to report the prevalence of non-strabismic anomalies of binocular vision among school children in rural and urban Tamil Nadu.

Methods
This population-based, cross-sectional study was designed to estimate the prevalence of non-strabismic anomalies of binocular vision in the rural and urban population of Tamil Nadu. In four schools, two each in rural and urban arms, 920 children in the age range of seven to 17 years were included in the study. Comprehensive binocular vision assessment was done for all children including evaluation of vergence and accommodative systems. In the first phase of the study, normative data of parameters of binocular vision were assessed followed by prevalence estimates of non-strabismic anomalies of binocular vision.

Results
The mean and standard deviation of the age of the sample were 12.7 ± 2.7 years. The prevalence of non-strabismic anomalies of binocular vision in the urban and rural arms was found to be 31.5 and 29.6 per cent, respectively. Convergence insufficiency was the most prevalent (16.5 and 17.6 per cent in the urban and rural arms, respectively) among all the types of non-strabismic anomalies of binocular vision. There was no gender predilection and no statistically significant differences were observed between the rural and urban arms in the prevalence of non-strabismic anomalies of binocular vision (Z-test, p > 0.05). The prevalence of non-strabismic anomalies of binocular vision was found to be higher in the 13 to 17 years age group (36.2 per cent) compared to seven to 12 years (25.1 per cent) (Z-test, p < 0.05).

Conclusion
Non-strabismic binocular vision anomalies are highly prevalent among school children and the prevalence increases with age. With increasing near visual demands in the higher grades, these anomalies could significantly impact the reading efficiency of children. Thus, it is recommended that screening for anomalies of binocular vision should be integrated into the conventional vision screening protocol.

http://onlinelibrary.wiley.com/doi/10.1111/cxo.12496/full

AIM:

To analyze changes in vergence and accommodative parameters of patients using TRYe Home therapy software.

MATERIALS AND METHODS:

This is a prospective non-randomized experimental study carried out at the Binocular vision/ Vision therapy clinic of Sankara Nethralaya, Chennai. Patients diagnosed with convergence insufficiency (CI) with or without an associated accommodative infacility (AIF) during the study period of June 2016 – June 2017, and willing to take the home vision therapy were included in the study. The improvement in near fusional vergence and accommodative facility parameters were analyzed pre-post home vision therapy in subjects who had completed minimum 25 sessions of home vision therapy.

RESULT:

The mean (SD) age of 20 subjects included in the study was 22.6±10.3 years (8 males). Six subjects had CI and Fourteen subjects had CI with AIF. Statistically significant improvement in vergence and accommodative parameters was observed post vision therapy (paired t-test, p<0.05). The mean (SD) improvement in convergence amplitudes was 19 Prism Diopters (PD), divergence amplitudes 9 PD, and binocular accommodative facility was 5 cycles/ minute. And also 55% of the subjects had achieved Convergence amplitude of 45PD, 15% had achieved Divergence amplitude of 30PD and 10% had achieved 15 cycles/ minute in binocular accommodative facility.

CONCLUSION:

Home vision therapy using a computer-based software proves to be a successful treatment option for subjects with convergence insufficiency. Further studies are warranted to compare the improvements with conventional vision therapy.

Purpose:

To identify the efficacy of computer-based binocular vision assessment in diagnosing non-strabismic binocular vision anomalies in comparison to the conventional method.

Results:

The mean age of 47 subjects included in the study was 20.23 (SD ±5.31) (Male to female ratio was 20:27); Based on the conventional manual assessment, 38 were diagnosed to have NSBVA and 9 had normal binocular vision. Among the 38 subjects with NSBVA, 2 had convergence insufficiency (CI), 12 had accommodative infacility (AIF), 19 had both CI and AIF and 5 had Divergence Insufficiency & AIF. With a cut-off of 15 prism Diopter (PD) for convergence, 7.5 PD for Divergence, 4 cycles per minute (CPM) for binocular accommodative facility and 3 CPM for monocular accommodative facility, the sensitivity and specificity of the TRYe software were found to be 1 and 0.82 respectively. The positive and negative predictive values of the software screening tool were 1 and 0.94 respectively.

Conclusion:

The software-based screening tool was found to be highly sensitive in identifying individuals with NSBVA. This could be used as a potential screening tool for NSBVA in the clinic and community.