Recovery of a Disinserted Medial Rectus Muscle after Pterygium Surgery

To report a case of recovery of a medial rectus which was accidentally disinserted after surgical treatment of a recurrent pterygium.

Report of a case of inadvertent medial rectus disinsertion after pterygium excision at a secondary care hospital which was referred to a tertiary care hospital in Northern Thailand.

A 40-year-old healthy woman was referred by a general ophthalmologist at a secondary care center to our hospital. She had undergone recurrent pterygium excision with amniotic membrane transplantation on the nasal side of her right eye. Immediately after the last operation, she complained of horizontal binocular diplopia. On the first postoperative day, the patient could not adduct the eye beyond the primary position. Her measurements in primary position were 45 prism diopters of right exotropia on distant and near. The diagnosis of iatrogenic medial rectus disinsertion was made. Three weeks after pterygium excision, revision surgery was performed; the medial rectus was found and reattached to its normal insertion site. On the first postoperative day, the patient referred a small vertical diplopia in the primary position. Orthoptic examination five months post-operatively demonstrated orthotropia and absence of diplopia in primary position, but minimal horizontal diplopia in right gaze.

Accidental rectus muscle disinsertion after pterygium excision surgery is a serious but rare postoperative complication of pterygium surgery. Great care should be taken intraoperatively to avoid this complication. Reattachment of the disinserted medial rectus will produce a satisfactory resolution of the problem.