Frequency of undetected binocular vision anomalies among ophthalmology trainees

The use of ophthalmic instruments requires increased effort on the accommodation and vergence system. This study aimed to understand the prevalence of binocular vision anomalies among ophthalmology trainees attending a surgical training program at a tertiary eye care center.

This prospective cohort study was carried out between April and November 2017 at a tertiary eye care center in South India. All the ophthalmology trainees inducted for the training programs at the institution underwent a comprehensive ophthalmic and binocular vision assessment. Subjects with previous diagnosis of binocular vision dysfunction and vision therapy were excluded.

The mean (SD) age of the subjects was 29 (3) among which 48 were females. Out of the total 75 subjects, 66 had prior surgical experience [range: 1 to 17 years]. Thirty-eight subjects were asymptomatic and 37 were symptomatic. The most common asthenopic symptom was the presence of headache. Forty-one (55%) out of the 75 had a diagnosis of a non-strabismic binocular vision dysfunction. The range of phoria at distance was orthophoria to 14 Prism Diopter (PD) exophoria (mean +/- SD: -1 +/- 3), and at near 4PD esophoria to 25PD exophoria (mean +/- SD: -4 +/- 5). Based on standard diagnostic criteria, 15 subjects (20%) had convergence insufficiency, 14 (19%) had accommodative infacility, 9 (12%) had intermittent divergent squint (IDS), while 3 subjects (4%) had convergence excess.

This study shows the high frequency of binocular vision dysfunctions among ophthalmology trainees joining a tertiary eye care center.