Purpose: To assess correlations between associated factors and treatment outcome of isoametropic amblyopia due to high hyperopia in children and to evaluate changes in retinal thickness during amblyopic treatment.
Methods: Isoametropic (spherical equivalent ≥5.00 diopters in both eyes) amblyopic subjects (n=225) with best corrected visual acuity (BCVA) ≤0.5 (20/40) for children <5 years old and BCVA ≤0.6 (20/32) for children 6-12 years old were included. All subjects were treated by fulltime wearing of optical correction and visual training. The magnitude of spherical equivalent hyperopia, age at first treatment, BCVA with Tumbling E charts, treatment duration, and binocular alignment were analyzed. Thicknesses of the retinal macula and nerve fiber layer were measured using optical coherence tomography in selected amblyopic children (n=27) during treatment and in control subjects (n=39).
Results: The mean follow-up was 28.6 months. The age at first optical correction ranged from 3 to 12 years (average 6.1 years). The mean visual acuity (VA) improved from 0.38 to 0.81, with 73.3% having acuity ≥0.8 and 27.6% having acuity ≥1.0. VA improvement was positively correlated with duration of treatment and negatively correlated with age at first correction. Foveal thickness slightly decreased after treatment; however, it was not correlated with visual improvement.
Conclusion: Visual acuity of isoametropic amblyopia improved satisfactorily with spectacle correction and vision therapy. Treatment duration had the greatest impact on VA improvement. Age at first correction also influenced VA improvement but was not a good clinical predictor. Foveal thinning occurring with treatment was not correlated with visual improvement.