Causes of retinal hemorrhage?

Hey all,

A friend of mine has been having some disturbing eye-related symptoms. Several weeks ago she was diagnosed with a small hemorrhage in her retina. Today she began experiencing vision trouble again. She was evaluated by her eye doctor and told that she had some more, small retinal hemorrhages, but that the visual disturbance she described was typical of migraine sufferers. This disturbance was in the same eye as the first hemorrhage. The visual disturbance went away about an hour after starting.

My friend has never experienced a migraine, and she is not diabetic. She has had brief spikes of dangerously high blood pressure in the last few years, but her blood pressure day-to-day is pretty normal. The causes of her previous high blood pressure spikes has never been confirmed, although emotional state was suggested as a possible cause.

We're wondering if there's anything that could be going on to cause these symptoms in one eye, other than the above conditions. I'm suspicious that there's something going on with that eye specifically, but her eye doctor keeps just telling her she must have either diabetes, high blood pressure, or migraines. Any doctors here who have heard of anything similar?