Amblyopia in patients with intermittent exotropia

Abstract

Aims: The aim was to report the incidence and types of amblyopia in a large series of patients with intermittent exotropia at a single institution. Materials and Methods: The medical records of consecutive patients 4–30 years of age diagnosed with intermittent exotropia at our institution between January 2000 and December 2017 were retrospectively reviewed for amblyopia. Results: A total of 2,058 patients diagnosed with intermittent exotropia during the study met the inclusion criteria. Of these patients, 40 (2%) had amblyopia and were the participants of this study. The mean patient age was 10.6 ± 4.2 years. Amblyopia was anisometropic in 35 (87%) patients and strabismic in 5 (13%) patients. Of the 35 patients with anisometropic amblyopia, 29 (83%) had spherical anisometropia and 6 (17%) had astigmatic anisometropia. There was no statistically significant difference in the number of patients and the mean anisometropia between patients with spherical anisomyopic and anisohyperopic amblyopia, and also between those with astigmatic anisomyopic and anisohyperopic amblyopia. There was no relation between the type of intermittent exotropia and anisometropic amblyopia. None of the patients with strabismic amblyopia had spherical or astigmatic anisometropia but had a preference for fixation with the nonamblyopic eye. There was no statistically significant difference in near and distance deviations between patients with anisometropic and strabismic amblyopia, and between those with anisomyopic and anisohyperopic amblyopia. Conclusions: Amblyopia was observed in 2% of our patients with intermittent exotropia. It was spherical anisometropic in a large majority of patients and strabismic in a few.