ISCHÆMIC OPTIC NEUROPATHY: THE CLINICAL PROFILE AND NATURAL HISTORY

Abstract

The clinical situation of acute optic disc infarction in middle-aged and senescent patients is not uncommon, yet with the exception of those instances due to giant-cell arteritis, pathophysiological mechanisms remain obscure. In hopes of elucidating this syndrome, the clinical profile and natural history of 37 cases of non-arteritic ischaemic optic neuropathy were reviewed. For contrast, 13 cases of arteritic optic neuropathy were surveyed. The salient features of idiopathic optic neuropathy may be summarized as follows: (1) the syndrome occurs primarily in 55-70-year-old patients who, for the most part, are otherwise well; (2) mild hypertension is present in about half of the cases, but does not determine a separate variant of the disorder; (3) there is no significant association with extracranial carotid occlusive disease; (4) over long follow-up periods there appears to be no increased incidence of stroke; (5) the syndrome should be easily recognized on clinical grounds, consisting of sudden or rapidly progressive monocular visual deficit associated with optic disc swelling, with stable visual defects of variable degree; (6) after an interval of months to many years, the second eye is involved in about 40% of cases (old optic atrophy coupled with contralateral fresh disc infarction may be confused with the Foster-Kennedy syndrome); (7) no form of therapy has proved efficacious; (8) pathophysiological mechanisms remain speculative. It is the responsibility of the physician, be he ophthalmologist or neurologist, to distinguish the patient with occult arteritis (history, physical examination, sedimentation rate, arterial biopsy) and institute immediate high-dosage corticosteroid therapy. It is also incumbent upon the clinician to desist from unnecessary and unrewarding diagnostic procedures, in particular cerebral angiography, when confronted with an instance of non-arteritic ischaemic optic neuropathy.