Long-Term Visual Outcome in Primary Microtropia

Abstract

To elucidate the long-term visual outcome of primary microtropia, a retrospective review was made on 31 patients with 5 years or more (5-16 years, mean: 9.2 years) follow-up. All patients showed anomalous retinal correspondence, peripheral fusion, 10 prism diopters or smaller esodeviation at the initial and final visit. At the initial visit, TNO stereoacuity was absent in 25 patients, 480 seconds in 2, and 240 seconds in 4. The visual acuity was 20/20 or better in both eyes of 16 patients, but 20/30 or worse in either eye or both eyes of 15 patients. At the final visit, the 25 patients with no stereoacuity still showed no stereoacuity while stereoacuity remained unchanged or got better in the 6 patients with initial stereoacuity of 480 seconds or better. The visual acuity in 7 of the 15 patients with 20/30 or worse became 20/20 or better while remained 20/30 or worse in the other 8 patients. No relation was found between no TNO stereoacuity and poor visual acuity. Patients with primary microtropia could be largely classified into those with no stereoacuity throughout the course and those with some levels of stereoacuity which had a chance to get better during the follow-up.