The impact of asymmetrical accommodation on anisometropic amblyopia treatment outcomes (in press)

Background:

Previous research revealed that the majority of children with anisometropic amblyopia have asymmetrical accommodation. Only 19% (5/26) had symmetrical accommodation, 58% (15/26) had aniso-accommodation and 23% (6/26) had anti-accommodation. The aim of this preliminary study was to determine if 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 (VA) in the amblyopic eye, post amblyopia treatment, was compared between those with symmetrical, aniso- and anti-accommodation.

Results:

There was a significant difference in final VA between the 3 accommodation groups (p = 0.023). The anisometropic amblyopes with anti-accommodation had the poorest final VA (0.42 ±0.25 (±95% CI) logMAR) with a statistically significant difference when compared to those with aniso-accommodation (0.14 ±0.08 logMAR; p = 0.023). However the difference failed to reach significance when compared to those with symmetrical accommodation (0.20 ±0.12 logMAR; p = 0.234), probably due to the small sample size. The initial VA in the amblyopic eye and the degree of anisometropia were also significantly positively correlated with final VA (both p < 0.001).

Conclusions:

The presence of anti-accommodation in anisometropic amblyopia was associated with a poorer amblyopia treatment outcome. The initial VA in the amblyopic eye and the degree of anisometropia were also associated with a poorer treatment outcome. It is possible that all these factors are associated but further research is required to determine causal relationships.