Age at Strabismus Diagnosis in an Incidence Cohort of Children

Purpose: To compare the age at diagnosis of children with esotropia, exotropia, and hypertropia. Design: Retrospective, population-based cohort study. Methods: The medical records of all Olmsted County, Minnesota, residents < 19 years diagnosed with esotropia, exotropia, or hypertropia from January 1, 1985 through December 31, 1994 were reviewed. Results: The median age at diagnosis of esotropia (n = 380), exotropia (n = 205), and hypertropia (n = 42) was 3.1 years, 7.2 years, and 6.1 years, respectively (P = .001). In the first six years of life, esotropia had the highest incidence and was more likely to occur than either exotropia or hypertropia; exotropia predominated between age seven and 12 years; and each form was similarly likely to occur between 13 and 18 years of age (P = .001). Conclusions: The age at diagnosis was significantly different for the various forms of strabismus in this population. Esotropia is the most common form in the first six years of life; beyond this age exotropia predominates until the teenage years when the three forms have a similar but decreased incidence.