Exotropia-Hypotropia Complex in High Myopia

Abstract

To highlight the association of exotropia-hypotropia complex in cases of high myopia and its surgical outcome. A retrospective study of 15 consecutive patients, diagnosed as having high myopia and exotropia-hypotropia, observed between January 2002 and May 2012 was performed. The main outcome measures were clinical presentation, orbital imaging features, and the surgical outcome of cases. Of the 15 patients, 9 were female. The median age was 23.5 years (range: 10 to 35 years). Thirteen cases had unilateral high myopia in the deviated eye. The mean axial length of the deviated eye was 29.43 ± 1.51 mm. Eight patients (53%) had a history of progressive eye deviation in adulthood. All patients had amblyopia of the deviating eye. The mean preoperative exotropia was 37.2 ± 8.72 prism diopters (PD) (range: 18 to 50 PD). The mean preoperative hypotropia was 12.73 ± 5.58 PD (range: 5 to 20 PD). An elevation deficit was noted in 6 patients (40%). On orbital imaging, high myopic eyes with deviation did not show significant displacement of rectus muscles in comparison to fellow eyes (P > .05, all rectus muscles). Eight cases (53%) were surgically managed with a median follow-up of 7 months. Intraoperatively, one case was found to have misplaced muscle insertion. Successful alignment was achieved by surgery on either horizontal rectus muscles alone (37%), or in combination with vertical muscles (62%). Exotropia-hypotropia complex can occur in association with high myopia. No specific etiologic factors, clinical or radiological, were identified in this study. Successful alignment may be achieved in these cases using tailor-made strabismus procedures.