Conservative management of intermittent exotropia to defer or avoid surgery

Background: Surgery for intermittent exotropia performed at a very young age has poorer sensory outcomes than surgery performed later; moreover, postoperative recurrence is common, regardless of age. Alternate occlusion decreases the size of the exotropia and improves control. The purpose of this study was to report the long-term effects of part-time alternate occlusion and overminus spectacles combined with prism on delaying or avoiding surgery in intermittent exotropia.

Methods: The study included consecutive patients from 1979 to 2010 who had poorly controlled intermittent exotropia and were treated with alternate occlusion, followed in some cases by overminus spectacles with base-in prism. Outcome measures were initial improvement and subsequent time to surgery, if required.

Results: A total of 279 patients had initial control poor enough to otherwise be considered candidates for surgery. After occlusion therapy, 219 (78%) improved their angle and control, and 62 (22%) converted to an exophoria. After 1 year, 9 cases deteriorated, and surgery was recommended. In 207 (74%), conservative treatment delayed surgery for at least 1 year. At 20 years, 42 of 279 patients were still being followed. Of these, 22 of 219 (7%) were known to have not undergone surgery, and 127 (45%) had undergone surgery; 130 (47%) were lost to follow-up.

Conclusions: Part-time alternate occlusion and overminus spectacles with prism can defer the need for surgery in a large percentage of patients with intermittent exotropia; for a small number it may be curative.