Changes in exodeviation following hyperopic correction in patients with intermittent exotropia

Abstract

PURPOSE: To evaluate changes in the angle of deviation after spectacle correction in patients who had hyperopia and intermittent exotropia (X(T)) and to determine whether the changes and surgical outcomes differ when compared with those of myopic and emmetropic X(T).

METHODS: One hundred fourteen patients with X(T) were recruited and allocated into three groups: X(T) with hyperopia (group I; 38 patients), X(T) with emmetropia (group II; 35 patients), and X(T) with myopia (group III; 41 patients). After at least 6 months wearing spectacles, changes in exodeviation were compared. The results of surgery based on the spectacle-corrected distance angle and the ratios of accommodative convergence over accommodation (AC/A) were also assessed.

RESULTS: With spectacle correction, the mean exodeviation increased significantly in group I, but did not change in groups II or III. Thirteen patients in group I (34%) showed a more than 10 prism diopters (PD) exotropic shift after wearing spectacles. The mean AC/A ratio in group I was 2.63 (PD/D), whereas in groups II and III the ratios were 4.03 and 4.06, respectively. There was no difference in surgical results among the three groups.

CONCLUSION: Although hyperopic correction in patients with X(T) resulted in a limited increase in exodeviation with a subnormal AC/A ratio, one-third of the patients experienced a significant increase in exodeviation. A spectacle correction trial should be considered before surgery in patients with hyperopia and X(T).