The ocular myopathy associated with dysthyroid1 (endocrine) exophthalmos remains an intriguing problem. The gross and histologic findings are well-known.2-7 Grossly, the extraocular muscles are firm, rubbery, and very much enlarged. Histologically, there is interstitial edema, round cell infiltration, and, in some cases, degenerative change within muscle cells. Similar changes are found in the orbital tissues in experimentally produced exophthalmos in guinea pigs.6,8-15 The edema is believed to be due to an increased content of waterbinding mucopolysaccharide, probably hyaluronic acid.16-18 The round cell infiltrate in animals and man includes lymphocytes, plasma cells, macrophages, and mast cells.16,18-20
The fine structure characteristics of extraocular muscle in dysthyroid exophthalmos have not yet been reported.
Materials and Methods
Biopsy material was obtained at the time of Krönlein orbital decompression from 19 mucles of 17 eyes of ten patients with dysthyroid exophthalmos37 (Table). The patients' ages ranged from 41 to
KROLL AJ, KUWABARA T. Dysthyroid Ocular MyopathyAnatomy, Histology, and Electron Microscopy. Arch Ophthalmol. 1966;76(2):244-257. doi:10.1001/archopht.1966.03850010246017