The effect of asymmetrical accommodation on anisometropic amblyopia treatment outcomes.

BACKGROUND: Previous research has revealed that the majority of children with anisometropic amblyopia have asymmetrical accommodation. The aim of this preliminary study was to determine whether the type of accommodation response was associated with a poor amblyopia treatment outcome in the same patients. METHODS: The type of accommodation response of 26 children with anisometropic amblyopia was determined in a previous study. The final visual acuity in the amblyopic eye, after treatment, was compared between those with symmetrical, aniso-, and anti-accommodation. RESULTS: The difference in final visual acuity between the three accommodation groups was significant (P = 0.023). Subjects with anisometropic amblyopia with anti-accommodation had the poorest final visual acuity (0.42 ± 0.25 logMAR) with a statistically significant difference compared with those who had aniso-accommodation (0.14 ± 0.08 logMAR; P = 0.023). However, the difference failed to reach significance compared to those with symmetrical accommodation (0.20 ± 0.12 logMAR; P = 0.234), probably due to the small sample size. The initial visual acuity in the amblyopic eye and the degree of anisometropia were also significantly positively correlated with final visual acuity (P < 0.001 for both). CONCLUSIONS: In this study cohort, the presence of anti-accommodation in anisometropic amblyopia was associated with a poorer amblyopia treatment outcome. The initial visual acuity in the amblyopic eye and the degree of anisometropia were also associated with a poorer outcome. It is possible that all these factors are associated, but further research is required to determine causal relationships.