Ischaemic optic neuropathy with painful ophthalmoplegia in diabetes mellitus.

Two patients with mild, adult-onset diabetes mellitus developed a painful ophthalmoplegia and ipsilateral optic neuropathy that was relatively unresponsive to steroids. Histopathological study of the optic nerve of one patient revealed an extensive ischaemic infarct. There was ultimate recovery from the cranial nerve palsies in both patients and the optic neuropathy in one patient. Ischaemic polyneuropathy involving the cranial nerves may cause an orbital apex/cavernous sinus syndrome in patients with diabetes mellitus.