Abstract
Purpose: :
To determine the efficacy of refractive correction (RC) alone and RC with patching in the treatment of amblyopia associated with myopic anisometropia. Association of visual acuity (VA) improvement with age, degree of anisometropia, patching compliance, strabismus, and eccentric fixation were also studied.
Methods: :
15 amblyopic subjects with a mean age of 9.36 yrs (5-13 yrs) were recruited. VA in the amblyopic eye ranged from 20/40 to 20/400. VA, cover test, stereoacuity, visuoscopy, and cycloplegic refraction were measured. Anisometropia was corrected by contact lens in the more myopic eye. VA was assessed at 4, 8, 12, and 16 weeks (wks) after subjects began to wear full refractive correction. Direct patching treatment, 2 hours daily for moderate amblyopia and 6 hours for severe amblyopia, was initiated at the 16-week visit. VA was assessed at 4 and 16 wks while patching. The primary outcome was LogMar VA after 16 wks of RC alone and after 16 wks of patching. General Linear Model repeated measures analysis was performed to assess the effect of RC alone and RC with patching on VA improvement. Association of VA improvement with other factors was evaluated by the Pearson correlation and multiple regressions.
Results: :
Mean±SD baseline LogMar VA in the amblyopic eye was 0.97±0.28 and significantly improved to 0.86±0.25 (P <0.0001) after 16 wks of RC alone and to 0.75±0.28 (P <0.0001) after 16 wks of patching. VA improvement by patching was significantly better than by RC alone (P=0.0007). VA improvement averaged 2.27 lines comparing the final to the baseline VA, with 7 of 15 subjects having final VA≥20/63. More VA improvement was identified in the children <8 yrs vs. those ≥8 yrs (P=0.005). Stereoacuity improved in 33% of subjects. The degree of anisometropia was strongly associated with baseline amblyopic eye VA (r=-0.805) and final VA following patching (r=-0.747); however, it was not associated with VA improvement. Patching compliance, strabismus, and eccentric fixation were not associated with VA improvement.
Conclusions: :
Both RC alone and RC with patching significantly improved VA in the amblyopic eye of subjects with myopic anisometropia. RC with patching improved VA more than RC alone.
Clinical Trial: :
www.clinicaltrials.gov MYAMB
Keywords: amblyopia • strabismus • myopia