Long-term study of accommodative esotropia.

PURPOSE: Previous studies of accommodative esotropia have been hampered by bias-prone methods of data collection and analysis and by small sample size. The studies have conflicting conclusions, causing uncertain results. This study aims to determine long-term results of standard treatment of accommodative esotropia and identify predictors of outcome, while minimizing bias in data collection and analysis, using the largest possible sample size. METHODS: A research assistant collected data from all files of a large, long-established pediatric ophthalmology practice (M.M.P.). The assistant was given standardized collection forms that allowed inclusion of all patient data points over all visits. The assistant was masked as to study goals. She was instructed to include any patient with esotropia who had been prescribed glasses during treatment. Descriptive terms were converted to code numbers. A second, similarly masked research assistant entered data into a computerized database. Criteria for patient inclusion were designed to conform to earlier studies by I.H.L. and M.M.P. and were implemented by computer. RESULTS: The database totaled 1,307 patients (747,717 data points). Of these, 354 qualified for this analysis. A greater difference between near and distance esodeviation (AC/A relationship) correlated with a higher rate of deterioration of accommodative esotropia control (P<.0001). Deterioration also positively correlated with earlier age at onset, inferior oblique overaction, and amblyopia. CONCLUSIONS: This study agrees with our previous findings that a high AC/A relationship increases the likelihood of deterioration of accommodative esotropia, thus confirming the integrity of the database. This unique, unbiased dataset will be used for future analyses of esotropia.