R Retinal/Ocular Migraine Daniel Croft 4 , Sumayya J. Almarzouqi 1 , Michael L. Morgan 1 and Andrew G. Lee 1,2,3,4,5 1 Department of Ophthalmology, Blanton Eye Institute, Houston Methodist Hospital, Houston, TX, USA 2 Departments of Ophthalmology, Neurology, and Neurosurgery, Weill Cornell Medical College, Houston, TX, USA 3 Department of Ophthalmology, The University of Texas Medical Branch, Galveston, TX, USA 4 Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA 5 Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, IA, USA Synonyms Ocular migraine; Ophthalmic migraine; Retinal migraine; Visual migraine Definition Retinal migraines (more properly retinal vaso- spasm) were defined in 1988 by the International Headache Society (IHS) as at least two attacks of fully reversible, transient monocular visual loss or disturbances associated with migraine headache. The complete diagnostic definition, as outlined by the IHS is detailed in the “Diagnostics” section below. However, recent literature challenges the notion that monocular visual loss is physiologi- cally associated with migraine headaches. Instead, some researchers propose that “presumed retinal vasospasm” with or without associated migraine would be a more accurate diagnosis for most patients. Etiology The pathophysiology of retinal migraine/vaso- spasm remains controversial. The two main criteria are monocular visual disturbance and migraine headache. Some cases of retinal vaso- spasm however do not have the migraine head- ache (acephalgic migraine equivalent). Proposed causes of migraine headache related neurologic deficit including visual loss include spreading depression or vasospasm. Retinal vasospasm is the predominant theory for “retinal migraine,” and the cortical spreading depression in bilateral migraine aura would be difficult to prove in the human retina causing monocular visual loss. Clinical Presentation Patients with retinal migraine/retinal vasospasm typically present after rather than during the visual symptoms. Rare patients with transient retinal vasospasm has been imaged and photographed. # Springer-Verlag Berlin Heidelberg (outside the USA) 2015 U. Schmidt-Erfurth, T. Kohnen (eds.), Encyclopedia of Ophthalmology , DOI 10.1007/978-3-642-35951-4_1225-1