Identification and Correction of Restrictive Strabismus After Pterygium Excision Surgery

To report the characteristics of patients with restrictive diplopia following pterygium excision and a successful treatment approach for the strabismus.

Retrospective interventional case series.

This study was set in a single academic institution and included 15 patients with restrictive diplopia after pterygium excision. Patients with any other reason for strabismus were excluded. Patients were evaluated for deficits with special attention to diplopic measures. The intervention was a combined procedure by a strabismologist and oculoplastic surgeon to correct the diplopia. The primary outcome measurements were subjective and objective improvement of diplopia.

Fifteen patients (mean age = 49 years) who developed diplopia after pterygium excision were included. Mean time to diplopia was 6 months. All patients had limited abduction in the previously operated eye causing esotropia in the abductive field (mean deviation = 18 prism diopters). After intervention, all patients were no longer diplopic in primary gaze. In the abductive field, 11 (73%) patients had residual small angle esotropia (mean = 7 prism diopters) in ipsilateral extreme end-gaze only. Only 2 patients required additional surgical intervention for scar tissue removal. No patients underwent medial rectus recession.

Restrictive diplopia is a potential complication after pterygium excision, particularly for patients with a history of recurrent pterygia requiring multiple excisions and previous amniotic membrane graft placement with fibrin glue. However, diplopia after pterygium excision in primary position is surgically correctable with scar tissue removal and ocular surface reconstruction, without needing medial rectus recession. Given the high volume of pterygium excision, awareness of postoperative restrictive strabismus and the potential for correction is critical.