Comparison of conventional occlusion and occlusion combined with physical exercise in adults with amblyopia: a randomized controlled trial.

Abstract

Purpose: Amblyopia in adults has traditionally been regarded as difficult to treat because cortical plasticity declines substantially after critical period. Recent neurophysiological research suggests that aerobic exercise can transiently enhance neuroplasticity, thereby potentially improving the outcome of visual rehabilitation. The present study aimed to evaluate whether incorporating physical exercise with conventional occlusion therapy can augment visual recovery in adults with unilateral amblyopia.

Methods: This prospective, randomized controlled trial included 60 adults aged 18-40 years diagnosed with unilateral amblyopia of strabismic, anisometropic, or mixed etiology. Participants were randomly assigned to one of two treatment groups. Group A (n = 30) received occlusion therapy consisting of patching of fellow eye for six hours daily. Group B (n = 30) received the same occlusion regimen supplemented with supervised aerobic exercise using a stationary cycle. Exercise sessions were conducted three times weekly during initial four weeks, each lasting two hours and comprising alternating cycles of 15-minute pedaling followed by 15 minutes of rest. Distant and near best-corrected visual acuity (BCVA) were designated as primary outcomes, while stereoacuity was assessed as the secondary outcome. All measurements were repeated at baseline and at monthly intervals for four months.

Results: The mean age of participants was comparable across groups (Group A: 22.60 ± 3.55 years; Group B: 22.63 ± 3.52 years; p = .94). Group B demonstrated a marked improvement in distant BCVA, from 0.92 ± 0.42 to 0.69 ± 0.34 logMAR (χ² = 101.1, p < .001), whereas Group A showed a smaller improvement from 0.84 ± 0.40 to 0.79 ± 0.41 logMAR (χ² = 26.4, p < .001). Near BCVA improved earlier and more substantially in Group B (p ≤ .03). Stereoacuity improved progressively in both groups, but longitudinal modeling revealed a significantly steeper improvement trajectory in Group B. 53% of Group B achieved measurable stereopsis compared with 27% of Group A. No adverse events occurred.

Conclusion: While both interventions resulted in significant visual improvement, the addition of exercise to occlusion therapy was associated with greater treatment gains. This combined approach appears efficient and safe.