Comparative Outcomes of Amblyopia Treatment in High Astigmatism: Stability and Sustained Improvements.

Background/Objectives: Astigmatism is a major risk factor for amblyopia. While optical correction improves visual acuity (VA), the long-term treatment outcomes, particularly in children with high astigmatism, remain understudied. This study aimed to determine the treatment effects, time course, and visual outcomes in children aged 3-7 years with high astigmatism and compared their VA improvement with those with low astigmatism. Methods: This retrospective cohort study included 63 children with untreated high with-the-rule astigmatism (≥+2.50 diopters [D]) and 46 with low astigmatism (≤1.50 D). The children with high astigmatism were classified based on their baseline best-corrected VA (BCVA) into good-VA (20/25 or better, n = 24), mild-VA-impairment (20/25-20/40, n = 19), and amblyopia (20/40 or worse, n = 20) groups. The primary outcomes include maximal improvement in mean BCVA post treatment, the cumulative probability of achieving a VA of 20/25 or better, and being within one line of the fellow eye. Results: The amblyopia, mild-VA-impairment, good-VA, and low astigmatism control groups showed mean improvements of logarithm of the minimum angle of resolution of 0.36 ± 0.08, 0.15 ± 0.05, 0.03 ± 0.04, and 0.01 ± 0.04, respectively. Post treatment with optical correction and/or patching over a mean duration of 46.61 ± 35.22 weeks, amblyopia resolved in all affected children. In the mild-VA-impairment group, only one child did not respond successfully to the treatment. The mean final VA showed no significant intergroup differences (p = 0.115). No amblyopia recurrence was observed at a mean follow-up of 118.33 weeks post resolution. Conclusions: Timely optical correction and patching effectively improve VA in children with high astigmatism, achieving outcomes comparable to those with low astigmatism.