Prevalence and clinical profile of non-strabismic binocular vision anomalies in the Nepalese population: A hospital-based study.

Purpose: To identify the prevalence of non-strabismic binocular vision anomalies in a systematically randomized sample of symptomatic, non-presbyopic subjects from a tertiary hospital, using a broader range of diagnostics signs.

Subjects and methods: The study was designed as hospital-based, cross-sectional, and analytical and was conducted from March 2022 to April 2023. Systematic random sampling was employed to select the subjects. Symptomatic subjects aged between 18 and 35 years with best-corrected visual acuity of 6/6 in each eye and no change in refractive error during the subjective refraction were included in the study.

Results: Out of the 231 subjects examined, 91 (39.39 %) were found to have non strabismic binocular vision anomalies. Of all the non strabismic binocular vision anomalies, 60 subjects (26 %) had binocular dysfunctions, 22 (9.5 %) had accommodative dysfunctions, and 9 (3.9 %) had both accommodative and binocular dysfunctions. The most common dysfunction was convergence insufficiency (18.2 %), followed by accommodative infacility (6.06 %) and fusional vergence dysfunction (3.9 %). The most prevalent symptom was headache (16.7 %), followed by visual fatigue (14.1 %).

Conclusion: Two-fifths of the symptomatic subjects have non strabismic binocular vision anomalies. It is essential to assess all accommodative and binocular parameters in order to arrive at a diagnosis of non strabismic binocular vision anomalies.