Clinical Effects of Myopia Correction on the Angle of Exodeviation in Patients with Intermittent Exotropia

Abstract

Purpose: To evaluate the extent to which myopia correction decreases distant exodeviation in patients with intermittent exotropia (IXT) and myopia.Methods: The medical records of patients with IXT who underwent myopia correction without surgical intervention were retrospectively reviewed. No patient evidenced anisometropia or amblyopia; all exhibited distant angles of deviation greater than 10 prism diopters (PD). The refractive errors of the eye with greater myopia were analyzed. Patients who underwent at least 3 months of follow-up were included. We recorded age, sex, the angle of deviation, the stereoacuity, and suppression status. Patients who did and did not evidence improvement were analyzed at 9 months in terms of change in the distant angle of deviation.Results: A total of 30 patients were analyzed. The average age was 8.27 ± 2.59 years. There were 18 (60%) males and 12 (40%) females. Twenty-four (80%) exhibited statistically significant decreases in the distant angle of deviation after wearing glasses for 3 months; the average value was 5.54 ± 3.59 PD (range 2-16 PD) (<i>p</i> < 0.001). We found no significant decrease from 3 months to > 9 months (1.17 ± 3.63 PD) (<i>p</i> = 0.129). In patients evidencing no improvement at 3 months, we found no significant change in the distant angle of deviation at either 3 months (3.00 ± 4.56 PD) (<i>p</i> = 0.102) or 9 months (-3.66 ± 4.41 PD) (<i>p</i> = 0.132).Conclusions: Eighty percent of IXT patients with myopia exhibited significant decreases in the distant angle of deviation after wearing glasses for 3 months, and this was well-maintained after 9 months.