Abstract

Purpose: Generally, amblyopia treatment is considered complete when visual acuity (VA) has stabilized at its maximal level. Anisometropic amblyopes corrected with spectacles continue to be exposed to aniseikonia related magnification differences that could disrupt fusion and prevent further visual improvement. Contact lenses do not induce these magnification differences. The purpose of this study was to examine VAs of the amblyopic eye. Patients were children who were previously maximally treated for anisometropic amblyopia with spectacles and occlusion therapy, and were later fit with contact lenses.

Methods: A retrospective chart review in our pediatric practice was undertaken. Our computer system was directed to find patients with anisometropia (≥1.00D) and amblyopia. Patients with strabismus, or poor compliance with spectacle wear or high astigmatism ≥ 2.00D were excluded. Twenty-one patients who were maximally treated with spectacles and occlusion therapy were identified. These patients had later chosen to wear contact lenses (age range 8-15 at contact lens fitting). The best Snellen VA before contact lenses but after maximal treatment for amblyopia was recorded. The best Snellen VA during the period of contact lens wear (at least one year) was recorded.

Results: Snellen acuities were converted to LogMAR decimal equivalents for analysis. The mean maximum VA prior to contact lens wear was 0.130±0.125. The mean maximum VA with contact lens wear was 0.073±0.101. All subjects demonstrated better acuity with contact lens wear. A paired t-test showed that the difference in these means was statistically significant (p<0.001). A sub-analysis was performed on subjects with acuities of 0.10 or worse prior to contact lens wear. In this group of 10 subjects, the mean maximum VA prior to contact lens wear was 0.219±0.130. The mean maximum VA with contact lens wear was 0.126±0.127. A paired t-test showed that the difference in these means was statistically significant (p<0.001).

Conclusions: The mean VA was better with contact lens wear than prior to contact lens wear in anisometropic amblyopes. This improvement occurred after VA had plateaued with traditional amblyopia occlusion therapy and spectacle wear. These results may suggest that contact lens wear can bring about improvements in VA following maximal therapy, perhaps by eliminating aniseikonic magnification differences between the two eyes.