A Case of Compressive Optic Neuropathy Secondary to Lymphoma of the Extraocular Muscles.

Compressive optic neuropathy is an urgent condition that may lead to blindness. We report a rare case of compressive optic neuropathy secondary to lymphoma of the extraocular muscles in which the vision was successfully rescued. A 67-year-old man presented with visual acuity of hand motion in the right eye for 1 month. Magnetic resonance imaging demonstrated enlargement of the medial and inferior rectus muscles with their tendons. Tendon enlargement, which is uncommon as Graves' orbitopathy, motivated us to perform a biopsy. Intravenous steroids following biopsy and chemotherapy after definitive diagnosis allowed for recovery of vision. Clinicians should be aware that enlarged extraocular muscles due to lymphoma can cause compressive optic neuropathy.