Prism adaptation in visually mature patients with esotropia of childhood onset

Abstract

Objective To investigate the role of prism adaptation in the visually mature population with esotropia onset before visual maturation. Design Retrospective, noncomparative case series. Participants Eighty-five patients, 26 prism adapted for near (PAN) and 59 prism adapted for distance (PAD), were included in the study. Methods Patients included in this study were older than 9 years and had esotropia with an onset before age 9. Mean follow-up was 30 months (range = 6 weeks–164 months). All patients had prism adaptation and subsequent surgical correction. Surgical success was defined as peripheral fusion on the Worth 4-dot test and ≤8 Δ deviation at near and distance on the simultaneous prism and cover test. Main outcome measures Response to preoperative prism adaptation and postoperative alignment and sensory results were examined. Results Twenty-six of the 85 patients had previous surgical esotropia correction. In the PAD group, 41 were responders. Seventeen of these had built their deviation ≥10 Δ with prism adaptation. All responders had surgery for their prism-adapted angle. Postoperatively, 34 of 41 (83%) responders and 6 of 18 (33%) nonresponders had fusion. In the PAN group, 17 were responders. Nine of these built their deviation with prisms. Postoperatively, 16 of 17 (94%) responders and builders and 1 of 9 (11%) nonresponders had successful surgery with sensory and motor fusion. Conclusions Adults with esotropia onset before visual maturation can be prism adapted and surgically treated with a predictable outcome of sensory and motor fusion. Those prism adapted for near with response can be successfully treated with surgery for the near deviation. Prism adaptation also aids in determining those who would benefit from larger amounts of surgery.