Purpose: To determine the probability of spontaneous resolution of esotropia with onset in early infancy.
Design: Prospective multicenter cohort study.
Methods: Eligibility criteria included age at enrollment 4 to < 20 weeks and an esotropia measuring at least 20 prism diopters (pd). The primary outcome measure was ocular alignment at 28 to 32 weeks of age. The esotropia was classified as resolved when there was a misalignment of 0 to 8 pd at the outcome examination either with or without spectacle correction.
Results: Outcome data were available for 170 of the 175 enrolled patients. The esotropia was classified as resolved in 46 of the 170 patients (27%, 95% confidence interval = 21% to 34%). Most of the resolved cases had an intermittent or variable deviation at enrollment. Resolution occurred in only one of 42 cases that had a constant esotropia > or = 40 pd on both the baseline and first follow-up examination and had a refractive error < or = + 3.00 diopters. In another patient, who had an esotropia of 35 pd at baseline and 40 pd at the outcome examination, the esotropia resolved subsequent to the outcome examination.
Conclusions: Esotropia with onset in early infancy frequently resolves in patients first examined at less than 20 weeks of age when the deviation is < 40 pd in size and is intermittent or variable. Cases with a constant deviation > or = 40 pd presenting after 10 weeks of age have a low likelihood of spontaneous resolution. Our results can be used to define a clinical profile for which persistence of the esotropia is sufficiently likely that surgical correction at 3 to 4 months of age could reasonably be considered.