Exotropic heavy eye syndrome in unilateral high axial myopia

To describe a pattern of combined exotropia and hypotropia in patients with unilateral high myopia and to suggest a surgical approach for their management.

In this observational study of 13 patients presenting with unilateral combined exotropia and hypotropia with high axial myopia in the deviating amblyopic eye, cycloplegic refraction, visual acuity, ocular motility, and orbital imaging findings were evaluated. For patients who had undergone surgery, the intraoperative findings and their surgical outcome were also analyzed.

Median age at presentation was 27 ± 14.6 years. In the deviated eyes, mean spherical equivalent was -13.6 ± 9 D; mean axial length, 28.3 ± 1.7 mm. The mean preoperative horizontal and vertical angles of deviation in primary gaze were 46.5 ± 12.1^Δ (range, 25-60) and 21.1 ± 6.5^Δ (range, 15-35), respectively. All patients had a V pattern, with limitation of elevation in abduction. Magnetic resonance imaging revealed no evident displacement of the lateral rectus muscles in all cases. Six patients (46%) had surgical intervention. In 5 cases, the lateral rectus was displaced inferiorly by a mean of 2.5 mm (range, 2-4 mm) and was recessed and transposed 8 mm upward. The muscle was then fixated to the sclera with a nonabsorbable polyester suture 2-4 mm behind its new insertion. Successful surgical outcome was achieved in 5 cases (83%).

Combined exotropia and hypotropia associated with high myopia shows an overlap in the clinical presentation of the heavy eye syndrome. Although not evident radiologically, downward displacement of lateral rectus muscle was documented intraoperatively.