Minus Lens Therapy in The Management of Children with Intermittent Exotropia

Purpose: Intermittent exotropia may be decreased by stimulation of accommodative convergence. Overcorrecting minus lens therapy has been used as a treatment for intermittent exotropia via this mechanism. Here, we aimed to determine the safety and efficacy of minus lens therapy in children with X(T) who are younger than six years old. Methods: A retrospective document review of 163 children with intermittent exotropia was performed. All patients were treated with overminus spectacles. Age, sex, visual acuity, cycloplegic refractive error, angle of deviation, exodeviation control rating score were recorded. After at least 12 months follow up, patients with manifest deviation based on history and clinical examination were considered treatment failures and underwent surgery. Results: Mean angle of deviation at initial visit was 24.7 prism diopters (PD) that improved to 10.6 PD (with overminus glasses). At the initial visit, exodeviation control score in 8 patients was good, in 29 was fair and in 126 was poor. After two years, among patients who were still under treatment, 103 patients had a good control score, 7 had a fair score, and 9 had a poor score. Sixty-eight patients (%42) with minus therapy achieved a good control score and did not require surgical intervention. Surgery had been performed on 92 (56%) children, with failure of minus therapy.Conclusion: Overminus therapy with spectacles can be effective for improving intermittent exodeviation control in young children. It can decrease the rate of surgical treatment and delayed it, too.