Visual Field Defects in Exophthalmos Associated with Thyroid Disease

Abstract

It is not widely recognized that exophthalmos associated with thyroid disease can be accompanied by visual loss due to involvement of the optic nerve. Loss of vision is used by many as an indication for surgical decompression of the orbit in patients with progressive exophthalmos. Through a better understanding of the factors responsible for such visual loss a more reasonable differentiation might be made between those patients who should have conservative therapy and those who should have, in addition, orbital decompression. This report concerns six patients in whom defects could be demonstrated in central visual fields indicative of optic nerve involvement within the orbit similar to optic or retrobulbar neuritis. Three patients showed pericentral scotomas in one or both eyes, and in three patients nerve fiber bundle defects were present (Fig. 1, Cases 3, 4, and 6). Although the pathogenesis of such optic nerve defects associated with thyroid disease is