Purpose: To describe historical and presenting features of infants with the onset of esotropia in early infancy to provide a better understanding of the clinical spectrum of the disorder.
Design: Prospective multicenter cohort study.
Methods: Eligibility criteria included age at enrollment 4 to < 20 weeks and an esotropia at near measuring at least 20 prism diopters (pd). Historical information was elicited from the parent or guardian. The esotropia was measured at near and characterized as constant, variable, or intermittent.
Results: 175 infants were enrolled. Their average age at enrollment was 97 +/- 26 days. The esotropia was characterized as constant in 56% of the patients, variable in 25%, and intermittent in 19%. Forty-nine percent of the deviations were > or = 40 pd. Most of the larger angle deviations were constant whereas the majority of the smaller angle deviations were intermittent or variable. The majority of patients first seen after 12 weeks of age had constant deviations (65%), whereas the majority seen before 12 weeks of age had intermittent or variable deviations (57%). At enrollment, amblyopia was diagnosed in 19% of patients.
Conclusion: The clinical presentation of esotropia in early infancy shows more variation in the esotropia's size and character than has been previously appreciated. Only a minority of the infants who are diagnosed to have esotropia before 20 weeks of age have the commonly accepted profile for congenital esotropia of a large-angle constant deviation. Amblyopia frequently develops, so an evaluation for amblyopia should be an integral part of the examination of an infant with esotropia.