The Relationship of Age and Other Baseline Factors to Outcome of Initial Surgery for Intermittent Exotropia

Abstract

To determine whether age at surgery is associated with surgical outcome of intermittent exotropia (IXT) at 3 years. Secondary analysis of pooled data from a randomized trial. A total of 197 children 3 to <11 years of age with basic-type IXT of 15-40 prism diopters (Δ) were randomly assigned to 1 of 2 surgical procedures for treatment of intermittent exotropia. Masked examinations were conducted every 6months for 3 years. The primary outcome was suboptimal surgical outcome by 3 years, defined as constant or intermittent exotropia of ≥10 Δ at distance or near by simultaneous prism and cover test (SPCT); constant esotropia of ≥6 Δ at distance or near by SPCT; or decrease in near stereoacuity of ≥2 octaves, at any masked examination; or reoperation without meeting any of these criteria. The cumulative probability of a suboptimal surgical outcome by 3 years was 28% (19 of 72) for children 3 to <5 years of age, compared with 50% (57 of 125) for children 5 to <11 years of age (adjusted hazard ratio= 2.05; 95% confidence interval= 1.16 to 3.60). No statistically significant associations were found between suboptimal outcome and other baseline factors (magnitude of deviation, control score, fixation preference, or near stereoacuity) (P values ≥ .20). This analysis suggests that in children with IXT, younger age at surgery (3 to <5 years) is associated with better surgical outcomes; however, further evidence from a randomized trial comparing immediate with delayed surgery is needed for confirmation.