Retinal migraine reappraised.

Retinal migraine is usually characterized by attacks of fully reversible monocular visual loss associated with migraine headache. Herein we summarize the clinical features and prognosis of 46 patients (six new cases and 40 from the literature) with retinal migraine based upon the International Classification of Headache Disorders-2 (ICHD-2) criteria. In our review, retinal migraine is most common in women in the second to third decade of life. Contrary to ICHD-2 criteria, most have a history of migraine with aura. In the typical attack monocular visual features consist of partial or complete visual loss lasting <1 h, ipsilateral to the headache. Nearly half of reported cases with recurrent transient monocular visual loss subsequently experienced permanent monocular visual loss. Although the ICHD-2 diagnostic criteria for retinal migraine require reversible visual loss, our findings suggest that irreversible visual loss is part of the retinal migraine spectrum, perhaps representing an ocular form of migrainous infarction. Based on this observation, the authors recommend migraine prophylactic treatment in an attempt to prevent permanent visual loss, even if attacks are infrequent. We also propose a revision to the ICHD-2 diagnostic criteria for retinal migraine.