Ocular Migraines

My query is in regard to Ocular Migraines. Over the last 8 to 12 months, 4 different occasions, I have had sudden onset of a strange, crescent shaped arc of sparkling light that resembled shards of broken prism crystals in the upper left area of my field of vision - not confined to one eye. Each time, it only lasted a short while; the longest episode was perhaps about an hour. I experienced no pain during any of the events. Each time, I was very tired, and on 3 of the episodes, I was driving my car. Each time, the 'lights' disappeared once I rested or relaxed.

I had no idea what it could possibly be... other than possibly a retina might be detaching- but figured it was unlikely as it was identical in both eyes- not being confined to one eye- and it disappears completely when I simply rest.

Got to talking to a friend of mine about it; who happens to be a nurse. She experienced precisely the same symptoms herself, and had it diagnosed as an Ocular Migraine. I am thinking this is quite possibly what is going on with me. I'm wondering how serious Ocular Migraines are, and why they occur. Are they more frequent in middle aged adults?

I am also curious if Ocular migraines are more frequent in people who have, or have had, Common Migraines - From the time I turned 17, I suffered from very severe common migraines; sometimes 3 or 4 a month. After passing 48 or so, they have  become infrequent, and are not nearly as terrible as they once were.

Any information on Ocular Migraines is welcome.
Thanks

[Ray T Oyakawa, MD]

We do not know why migraines occur.  Ocular migraine and common migraine are variants of the same disease.  Common migraine is followed by headache where as ocular migraine has no headache.  Mechanism is the same.  The visual symptoms are related to constriction of blood vessels and the headache is related to the dilation phase.  This is probably to compensate for the ischemia (lack of blood flow) during the visual phase.

Rare complication is a migraine is a stroke.

Dr. O.