Assessment of eye movement endurance using the OculoMotor Assessment Tool: A replication study on young Indian adults

This replication study sought to determine (1) the frequency of horizontal/vertical saccades, vergence jumps, and horizontal/vertical vestibulo-ocular reflexes (VORs) elicited per minute in young Indian adults using the OculoMotor and Vestibular Endurance Screening (MoVES) protocol with the OculoMotor Assessment Tool (OMAT) and (2) the association between the participant's MoVES values and routine clinical binocular vision status.

Two hundred twenty-two healthy participants (17-33 years) repeatedly generated the aforesaid eye movements using the OMAT as a target for 60 s. A subset (n = 75) also underwent binocular vision assessment using standard optometric protocols. Eye movement frequency of participants with a near point of convergence ≤ 6 cm, stereoacuity ≤ 70 arcsec, and BIVSS score ≤ 31 constituted the normative cohort.

Eye movement responses of 153 participants who formed the replication cohort showed a higher frequency in the last 30 s compared to the initial 30 s (p < 0.01). The overall frequency of vergence jumps was lower in those who failed these criteria, vis-à-vis, the pass cohort (p < 0.01). These values were lower than previously published data from USA (p ≤ 0.05), but the differences diminished when matched with participants in organized sports activities. The clinical binocular vision parameters did not show a strong correlation with oculomotor frequency (r ≤ 0.3).

The endurance values of eye movements established here allow screening for oculomotor dysfunctions in young Indian adults. These values may be impacted significantly by the level of organized physical activity engaged by the participant. Routine binocular vision evaluation does not correlate with eye movement endurance values, reflecting the need for dedicated assessments of the latter functions using standardized techniques and tools.