Prismatic Correction of Consecutive Esotropia in Children after a Unilateral Recession and Resection Procedure

Abstract

To determine the long-term efficacy of prismatic correction in consecutive esotropia after a unilateral recession and resection (RR) procedure for primary exotropia. Retrospective cohort study. A total of 110 patients with esodeviation of 5 prism diopters (PD) or more at 4 weeks after the unilateral RR procedure for primary exotropia who were fitted with prism glasses and were followed up for a minimum of 2 years after primary surgery. Patients were divided into 2 groups based on whether they were weaned off the prism glasses within 1 year: (1) the prism-weaned group whose esotropia decreased enough for them to be weaned off the prism within 1 year; (2) the prism-wearing group who wore prism glasses for more than 1 year. Clinical characteristics and changes in deviation angle were compared between groups. The period of prism wearing, the rate of decline in deviation angle after prismatic correction, and preoperative and postoperative motor and sensory outcomes. The average age of patients was 4.7 years. Overall, the average period of prism wearing was 20.9 months, and the rate of decrease in the deviation angle was 2.9 PD per 6 months. Thirty-four patients (32%) were weaned off the prism glasses within 1 year. The prism-weaned group showed more preoperative constant deviation and anisometropia compared with the prism-wearing group. Overall, successful motor outcome was achieved in 71% of patients. The rate of recurrence during follow-up was higher in the prism-weaned group, and the rate of overcorrection was higher in the prism-wearing group (P = 0.003). No patients demonstrated new onset amblyopia, and 1 of the 105 patients (0.95%) demonstrated loss of stereoacuity as a result of overcorrection. At the final visit, stereoacuity was improved or was maintained in 92% of patients compared with preoperative values. Prismatic correction can lead to good motor outcomes while maintaining favorable sensory status in most patients with consecutive esotropia. Patients showed different clinical manifestations and outcome according to the period of prismatic correction. Patients in the prism-weaned group showed a faster change in esodeviation after prismatic correction and more exotropic drift after prism weaning, resulting in a higher rate of recurrence of exotropia.