Prismatic correction of residual esotropia of 20 prism dioptres or less after full hypermetropic correction

Abstract

To assess the efficacy of prismatic correction of residual esotropia <or=20 prism dioptres (PD) after full hypermetropic correction in patients with partially accommodative esotropia. Medical records of 64 patients who received prismatic correction for residual esotropia </=20 PD were reviewed. Outcomes were considered successful if patients maintained orthotropia or esophoria for at least 1 year and did not require surgery. Factors including age, sex, visual acuity, refractive errors, amount of deviation, sensory status, and the presence of amblyopia were analysed and compared between the success and failure groups. Prismatic correction was successful in 28 of 64 patients (44%). The success group showed better results both with Worth 4-dot test (P=0.001 at distance and P=0.046 at near) and Randot stereo test (P=0.003 for dots and P=0.000 for animals). Success rate increased to 58% without amblyopia, 72 and 93% with normal fusional response at near and at distance with Worth 4 dot test respectively, and 92% with stereoacuity of 800 s of arc or better. In all patients in success group, fusion and stereoacuity improved or maintained during follow-up. Prismatic correction was successful in 44% of the patients with residual esotropia <or=20 PD and the success group showed an improved or stable sensory status with time. With a baseline fusion on Worth 4-dot test or stereopsis of 800 s of arc or better, prismatic correction could be considered as the first-line treatment.