Anterior ischaemic optic neuropathy. III. Treatment, prophylaxis, and differential diagnosis.

Anterior ischaemic optic neuropathy (AION) is a serious blinding disease, with poor prognosis for the recovery of vision and a high probability that the second eye will be involved. Since we have only recently begun to understand its pathogenesis (Hayreh, I 974a,b) and most of the therapies tried so far (reviewed by Hayreh, 1974b) have made no significant difference to their visual loss, such patients are generally given up as hopeless. The main therapeutic controversy lies in the management of the non-arteritic type of AION since patients with temporal arteritis AION are invariably treated with systemic corticosteroids, primarily to prevent the involvement of the second eye. In the management of the nonarteritic type of AION, many therapies have been tried, e.g. anticoagulants (Lasco, I96I; Saraux and Murat, I967), systemic corticosteroids (Foulds, i968, 1969), subtenon vasodilators (Fransois, Verriest, Neetens, De Rouck, and Hanssens, I962; Calmettes, Deodati, and Bechac, I963; Bonamour, I966; Saraux and Murat, I967), subtenon steroids (Bonamour, I966; Sanders, 1971), subtenon atropine sulphate i per cent. (Cordes, I937), and recently diphenylhydantoin (Burde, 1973). However, most ophthalmologists do not treat patients with the non-arteritic type ofAION or try to find a treatable associated systemic or ocular disorder, e.g. hypertension, diabetes, anaemias, glaucoma, etc. (Hayreh, I974a,b), but discard them with philosophical advice to accept the visual loss as a natural calamity. In the present study, attempts were made to evaluate systemic corticosteroid therapy in AION. When patients were treated early, while they still had oedema of the optic disc, with large doses, there was visual improvement in a significant number of cases; almost all of these patients had AION due to causes other than temporal arteritis. Since the non-arteritic type of AION forms a much larger group than temporal arteritis AION, this is an important ray of hope in the gloomy picture of AION. Lowering the intraocular pressure, particularly by Diamox, has also been found to be helpful.