Extraocular muscle enlargement after orbital decompression for Graves' ophthalmopathy.

Three patients who had orbital decompression for compressive optic neuropathy secondary to Graves' ophthalmopathy are presented. Despite initial improvement in their visual acuity, all of the patients experienced subsequent relapse due to progressive enlargement of the extraocular muscles, resulting in recurrent compressive optic neuropathy. Management consisted of reoperation, systemic prednisone, and retrobulbar radiation. Enlargement of the extraocular muscles is felt to be caused by continuation of the autoimmune process and/or expansion of the extraocular muscles after slitting of the periorbita and bony removal of the orbital walls.