Abstract
PURPOSE: To investigate the incidence of comitant esotropia (ET) with diplopia using a large insurance claim database in the United States. DESIGN: A retrospective cross-sectional study. SUBJECTS: A large health insurance database. METHODS: Claims for comitant ET with diplopia were extracted using a combination of ET- and diplopia-related codes. The claim ratio of ET to strabismus was calculated from 2007 to 2022. Age and sex distributions were compared between the first (2007-2014) and second (2015-2022) half periods. MAIN OUTCOME MEASURES: Change of ratio of ET with diplopia to all strabismus claims. RESULTS: In total, 38 404 ET claims were identified among 1 516 779 strabismus claims. The mean age of the ET claims was 39.0 ± 17.4 years. A more marked female predominance in ET claims (male:female = 1:1.6) than in strabismus claims (1:1.1) was observed. The ET claim ratio linearly increased from 1.27% in 2007 to 3.49% in 2022 (adjusted R (2) = 0.856, P < 0.001). The mean age of the ET claims was lower in 2015 to 2022 than in 2007 to 2014 (38.4 vs. 40.0 years, P < 0.001). The female predominance was more marked during 2015 to 2022 than in 2007 to 2014 (1:1.8 vs. 1:1.3, P < 0.001). The sex distribution of the younger age group (<39 years) changed from male predominance in 2007 to 2014 to female predominance in 2015 to 2022. CONCLUSIONS: The proportion of comitant ET with diplopia in strabismus has increased since 2007 in the United States. The increase was most pronounced in young patients. Female predilection in comitant ET with diplopia was observed, and the change from male to female predominance over time was remarkable among young patients. FINANCIAL DISCLOSURES: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.