Slipped Medial Rectus Muscle With Stretched Scar After Pterygium Surgery.

The authors report a rare case of slipped medial rectus muscle with stretched scar in the left eye of a 45-year-old woman following pterygium surgery. There was total limitation of adduction in her left eye with complaints of diplopia in all gazes with maximum separation of images in dextroversion on diplopia charting. Hess charting showed underaction of the medial rectus muscle of the left eye and overaction of the lateral rectus muscle of the right eye. Based on the history and findings, a diagnosis of medial rectus muscle disinsertion of the left eye during pterygium surgery was made. Medial rectus muscle exploration was done and the slipped medial rectus muscle was found attached to its original insertion site via pseudotendon/stretched scar. The capsule was dissected, the scar tissue was excised, and the slipped medial rectus muscle was identified, hooked, and secured with sutures. The muscle was reattached with advancement. Postoperatively, the patient was orthotropic and there was no diplopia. Accidental medial rectus muscle disinsertion during pterygium surgery is a rare but serious complication. Proper care should be taken intraoperatively during pterygium surgery to avoid this complication. However, meticulous surgical exploration and reattachment of the muscle yields satisfactory results. [J Pediatr Ophthalmol Strabismus. 2019;56:e34-e37.].