Eyelid Fissure Narrowing after Recession of the Medial Rectus Muscle

A 67-year-old male had suffered from eye movement disturbance from Graves’ orbitopathy. His right eye was fixed in an esotropic position. Examination by synoptophore showed that his right eye deviation was 22 degrees medially. The upper eyelid margin reflex distance (MRD) was 3.5 mm OD and 5.6 mm OS, and the lower eyelid MRD was 5.1 mm OU. Six mm medial rectus muscle recession with tenotomy was performed in the patient. The next day after the surgery, his eye position did not change and the right eyelid fissure demonstrated narrowing with upper eyelid lowering and lower eyelid elevation. The right upper eyelid MRD was decreased to 1.9 mm and the right lower eyelid MRD was similarly decreased to 4.3 mm. On the same day, 4 mm resection of the ipsilateral lateral rectus muscle was performed, but the same MRDs were observed postoperatively. Patients undergoing medial rectus muscle recession in Graves’ orbitopathy need to be informed of this potential complication.