Long-term Motor and Sensory Outcomes After Unilateral Lateral Rectus Recession-Medial Rectus Resection for Basic Intermittent Exotropia.

PURPOSE

To report long-term motor and sensory outcomes after unilateral lateral rectus recession-medial rectus resection for basic intermittent exotropia.

METHODS

The medical records of patients who had undergone unilateral lateral rectus recession-medial rectus resection for basic intermittent exotropia and were observed postoperatively for a minimum of 10 years were reviewed retrospectively.

RESULTS

A total of 41 patients were included (mean age: 6.07 ± 2.96 years; range: 3 to 17 years). The mean postoperative follow-up was 13.28 ± 3.27 years (range: 10 to 23 years). Overall, 19 patients (46%) had surgical success at their most recent follow-up visit. Age at onset of strabismus, age at surgery, strabismus duration, preoperative size of near and distance deviation, presence of stereopsis, and initial postoperative overcorrection did not predict motor outcome after surgery. Twenty-five patients (74%) achieved stereopsis. None of the 4 patients without binocular single vision preoperatively achieved stereopsis, compared to 3 of 7 patients (43%) with peripheral binocular single vision (P = .02). Five of 7 patients (71%) with a preoperative stereoacuity of 120 to 240 seconds of arc improved to 60 seconds of arc. Age at surgery did not predict stereopsis. Patients with a strabismus duration of 5 years or less achieved a better stereopsis.

CONCLUSIONS

Fewer than half of the patients with basic intermittent exotropia achieved a successful long-term surgical outcome. Age at surgery, strabismus duration, preoperative stereopsis, and an initial postoperative overcorrection did not predict motor outcome. A pre-operative absence of binocular single vision indicated a poor prognosis for stereopsis. A shorter duration of strabismus predicted a better stereopsis after surgery. [J Pediatr Ophthalmol Strabismus. 2020;57(5):326-332.].