Risk factors for treatment failure of anisometropic amblyopia

J AAPOS. 2004 Oct;8(5):429-34. doi: 10.1016/j.jaapos.2003.09.005.


Purpose: This study sought to explore factors which might predict the lack of vision improvement following therapy of anisometropic amblyopia.

Methods: We retrospectively reviewed the records of 104 children aged 3 to 8 years who had anisometropic amblyopia with a difference in the refractive power between the two eyes of at least 1 diopter, a difference in corrected visual acuity between the two eyes of at least 3 logMAR units, visual acuity in the amblyopic eye of 20/50 or worse, and no ocular structural abnormalities. Patients were treated with either patching or atropine penalization therapy. Patients with strabismus were included. Treatment failure was defined in two ways: (1) functional failure indicating a final visual acuity in the amblyopic eye worse than 20/40 and (2) relative failure indicating less than three lines of logMAR visual acuity improvement regardless of final vision.

Results: Failure risk factors were as follows: age above 6 at the onset of treatment (adjusted odds ratio [OR] (95% confidence limits [CL] = 4.69 [1.55, 14.2]), the presence astigmatism of more than 1.50 diopters in the amblyopic eye (adjusted [OR] (95% CL) = 5.78 [1.27, 26.5]), poor compliance with treatment (adjusted [OR] (95% CL) = 5.47 [1.70, 17.6]), and initial visual acuity in the amblyopic eye of 20/200 or worse (adjusted [OR] (95% CL) = 3.79 [1.28, 11.2]). Strabismus was not found to be a significant risk factor. Neither the type or amount of refractive error nor the difference in the refractive power between the two eyes was a significant risk factor for treatment failure.

Conclusion: Eyes with poor initial visual acuity, the presence of significant astigmatism, and age over 6 years were less likely to achieve successful outcome. The clinical profile of patients with anisometropic amblyopia may be useful in predicting response to therapy, but compliance with treatment has a major effect on response to therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Amblyopia / therapy*
  • Anisometropia / therapy*
  • Astigmatism / complications
  • Atropine / therapeutic use
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Male
  • Mydriatics / therapeutic use
  • Patient Compliance
  • Retrospective Studies
  • Risk Factors
  • Sensory Deprivation
  • Strabismus / complications
  • Treatment Failure*
  • Visual Acuity


  • Mydriatics
  • Atropine