title: Risk factors for treatment failure of anisometropic amblyopia.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Cullen Eye Institute, Baylor College of Medicine, Department of Ophthalmology, Texas Children's Hospital, Houston 77030, USA.
authors.forename: Mohamed A W
authors.initials: MA
authors.lastname: Hussein
authors.forename: David K
authors.initials: DK
authors.lastname: Coats
authors.forename: Arpitha
authors.initials: A
authors.lastname: Muthialu
authors.forename: Ethan
authors.initials: E
authors.lastname: Cohen
authors.forename: Evelyn A
authors.initials: EA
authors.lastname: Paysse
mesh_terms: D000367:Age Factors; D000550:Amblyopia / Q000628:therapy*; D015858:Anisometropia / Q000628:therapy*; D001251:Astigmatism / Q000150:complications; D001285:Atropine / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000627:therapeutic use; D010349:Patient Compliance; D012189:Retrospective Studies; D012307:Risk Factors; D012683:Sensory Deprivation; D013285:Strabismus / Q000150:complications; D017211:Treatment Failure; D014792:Visual Acuity
chemical_list: D009184:Mydriatics; D001285:Atropine