A pilot randomized trial evaluating overminus spectacles versus part-time occlusion for control of intermittent exotropia among children 2–10 years of age

Abstract

Purpose The aim was to compare the short-term effectiveness of overminus spectacles versus part-time occlusion (PTO) in improving control of intermittent exotropia [X(T)]. Patients and methods A total of 60 children with X(T), from 2 to 10 years of age, were included in the study. Their distance office control score started from 2 or worse. This is a clinical, randomized, prospective, pilot study. Children were randomly assigned to overminus spectacles, PTO therapy, and observation for 4 months followed by 2 months without treatment. Results The mean distance exotropia control score after 4 months of treatment improved significantly in the overminus spectacle and the PTO groups from 3.9 vs. 3.9 to 2.0 vs. 2.7, respectively. After stoppage of treatment for 2 months, the score deteriorated significantly to 3.3 and 3, respectively. The observation group’s score showed nonsignificant change all throughout the study period. There was a significant improvement in both mean near and distance angles only in the overminus spectacle group after 4 months of treatment and a significant deterioration after 2 months without treatment. Both near and distance angles showed nonsignificant change in both PTO and observation groups all throughout the study period. There was also a significant correlation between the poor compliance of the patients and their deterioration in the PTO group. Conclusion Overminus spectacle therapy has proved to be more effective in control of X(T) than PTO therapy. Poor compliance in PTO therapy affects the treatment effectiveness. It is suggested to work on a protocol of treatment cessation in further studies.

Keywords

• intermittent exotropia
• overcorrecting minus spectacles
• part-time occlusion