Clinical features and change in incidence of acute acquired comitant esotropia: a 15-year single-center study in South Korea

Abstract Background/Objectives: We investigated the clinical features and change in incidence of AACE in South Korea.Subjects/Methods: This study reviewed the medical records of new patients who visited the Strabismus and Pediatric Ophthalmology Clinic (clinic of YHL) from January 1, 2007, to December 31, 2021. Patients with AACE or intermittent exotropia (IXT) were eligible for inclusion in the study. Clinical features were retrieved, including age at onset, angle of deviation, refractive errors, neuroimaging findings, and treatment outcomes. For each year, the proportion of new AACE patients among all new patients who visited the clinic, and the ratio of new AACE patients to new intermittent exotropia (IXT) patients, were analyzed to estimate the incidence of AACE.Results Overall, 59 patients were included in the study. The mean age of the patients was 24.7 ± 9.3 years; the incidence of AACE was highest in teenagers and young adults. The proportion of new AACE among all new patients showed increasing trend and it was statistically significant. (Linear regression analysis, R2 = 0.778, p < 0.001). There was also a significantly increasing trend in the ratio of new AACE patients to new IXT patients (R2 = 0.803, p < 0.001).Conclusions A new type of AACE, distinct from the classic types, is increasingly common in South Korea; this increasing incidence also appears to be a global phenomenon. Large-scale investigations are needed to define the exact clinical features, incidence, and pathophysiology of this new type of AACE.