To report a case of anterior segment ischemia after superior and inferior rectus muscle surgery in a patient with superior rectus muscle enlargement. This is the first report in the Republic of Korea of anterior segment ischemia after two rectus muscles surgery.

An 80-year-old male was referred to our clinic with a 3 years history of diplopia. The patient had 30 prism diopters right eye hypertropia in the primary position and downgaze limitation. The orbital computed tomography scan revealed enlargement of the right superior rectus muscle. He underwent right superior rectus recession and inferior rectus resection. On postoperative day 2, slit lamp examination revealed diffuse corneal edema, Descemet's membrane folding, an aqueous flare and a dilated pupil. Treatment with 45 mg oral steroid was initiated, and 1% prednisolone acetate and 0.5% Levofloxacin eye drops were administered. At postoperative 1 month, the patient was orthophoric in the primary position, and there was no corneal edema, pupil abnormality or aqueous flare.

Base on the present case, the possibility of anterior segment ischemia should be considered after even two muscles surgery, and older patients with vertical muscle surgery should be considered more carefully.