Effect of Vergence Facility Testing on Horizontal Fusional Reserves

This study aimed to compare the effect of vergence adaptation after different vergence facility (VF) testing methods on following horizontal fusional reserve measurement at near.

METHODS

This cross-sectional study was performed on 50 healthy subjects with a mean ± standard deviation age of 21.18 ± 1.41 years. The baseline horizontal fusional reserves were measured using base-in (BI) and base-out (BO) prisms (∆) at near. Then, VF was measured using 3∆BI/12∆BI flip prism at near, and then the measurement of fusional reserves was repeated. In the next step, fusional reserves were measured after VF testing using 8∆BI/8∆BO flip prism. The values of fusional reserves were compared with their baseline findings.

RESULTS

The results of negative fusional reserves after VF measurement using the 3∆BI/12∆BO prisms were significantly lower than the baseline values (blur [P = .03], break [P = .03], and recovery [P = .03]). There were no significant differences between the values of fusional reserves before and after VF testing using the 8∆BI/8∆BO prisms (P> .05). No correlation was observed between fusional reserves and VF responses (P> .05); however, the results revealed a positive correlation between the values of fusional reserves before and after VF testing using both methods (all P

Source: Optometry and Vision Science - January 1, 2022 Category: Opthalmology Tags: ORIGINAL INVESTIGATIONS Source Type: research