EXTRAOCULAR-MUSCLE ENLARGEMENT AFTER ORBITAL DECOMPRESSION FOR GRAVESOPHTHALMOPATHY

Three patients who had orbital decompression for compressive optic neu ropathy secondary to Graves' ophthalmopathy are presented. Despite ini tial improvement in their visual acuity, all of the patients experienc ed subsequent relapse due to progressive enlargement of the extraocula r muscles, resulting in recurrent compressive optic neuropathy. Manage ment consisted of reoperation, systemic prednisone, and retrobulbar ra diation. Enlargement of the extraocular muscles is felt to be caused b y continuation of the autoimmune process and/or expansion of the extra ocular muscles after slitting of the periorbita and bony removal of th e orbital walls.