Purpose: To compare the measurements of accommodative amplitude and lag of accommodation in the fellow eyes of patients with various stages of anisometropic amblyopia and healthy eyes.
Method: In this cross-sectional study, 72 children with the mean age of 6.03 years (range between 4 to 9 years) with different severities of unilateral functional amblyopia (mild, moderate, and severe) were included. The mean values of accommodative amplitude and lag of accommodation were compared between the study groups (mild, moderate, and severe amblyopia) and the healthy participants.
Results: There were 23 (31.9%) fellow eyes of patients with unilateral mild amblyopia, 8 (11.1%) fellow eyes of patients with unilateral moderate amblyopia and 5 (6.9%) fellow eyes of patients with unilateral severe amblyopia. In terms of accommodative measurements in different study groups, we found that accommodation lag was significantly higher in healthy eyes compared to mildly, moderately, or severely amblyopic eyes amblyopic eyes (all P<0.05). When comparing the fellow eyes of mild amblyopes to more severe amblyopes, accommodation lag was only significantly different between mild and severely amblyopic fellow eyes (P<0.05). No other between-group comparisons showed a statistically significant difference.
Conclusion: The findings indicate that unilateral amblyopia primarily impacts the accommodative lag response, rather than the maximum amplitude that can be achieved. The lag of accommodation in the fellow eyes of amblyopic patients was found to increase progressively with greater amblyopic severity, demonstrating higher accommodative dysfunction and amblyopia severity. In contrast, no significant associations were observed between amblyopia and amplitude of accommodation.