Temporary vision loss could signify a transient ischemic attack

Dear Dr. Roach: My father is in his mid-60s and recently underwent surgery to repair mitral valve prolapse. Everything went smoothly, and his recovery has been good, with the exception of this morning. He has resumed smoking (after telling his doctors that he quit), and he experienced a dizzy spell where his vision in one eye became hazy, then gray, then black. His blood pressure was fairly high at this time. He sat down, and after several minutes, his vision slowly returned.He has seen strobe lights in his peripheral vision a couple of times in the past. His doctor attributed this to ocular migraines, but my father has no history of migraines. His doctor believes the cause of his episode this morning was a retinal migraine caused by dehydration. I'm afraid it might have been a transient ischemic attack (TIA) and that he could end up having a stroke. What do you advise? — L.S.Answer: Transient loss of vision in one eye is called "amaurosis fugax" and is often considered a TIA, which is a big warning sign of an impending stroke. You are wise to take it seriously. Many people minimize serious symptoms until it is too late.There are several factors that make me concerned about a TIA, including his recent surgery. Surgery is a major risk factor for blood clotting. Smoking is another big risk factor.It is true that migraines can cause a temporary loss of vision. Since he has never had a migraine, this diagnosis is less likely. What makes it even less likely is that migraines almost always have visual changes, such as scintillations. Still, it could be possible that this is a migraine phenomenon, since they don't always obey the "rules" written in textbooks.The change in vision from blurry to grey to black is not out of the ordinary for a TIA, which happens when the blood flow to the retina is interrupted, often from a blood clot. However, the episode's duration of a few minutes is more consistent with a TIA than a migraine. One unusual cause, giant cell arteritis (GCA), needs to be evaluated because vision loss can be permanent in this case.Given how serious a TIA is, I strongly encourage him to get an urgent evaluation, including a careful eye exam by an expert; an evaluation of the blood vessels of his neck by ultrasound or CT/MRI angiography; and blood testing for GCA.If all testing comes out looking good, his doctor may have been right. Still, a stroke can cause permanent loss of brain function, and his risk is high enough that he's doing himself a disservice if he does not get evaluated.Dr. Roach Writes: A recent column on Dupuytren's contracture generated several letters, some of which advised needle fasciotomy. This is an alternative to the options I discussed, which were traditional surgery, radiation and collagenase injection.A well-done trial published in March showed that after two years, traditional surgery had the best results with 78% success, compared to 65% in the collagenase patients and 50% in the needle fasciotomy group. Success was defined by a contracture release of more than 50% and "acceptable" control of symptoms.There still may be good reasons to choose alternatives to surgery with some patients, but better long-term results were found with traditional surgery in this study.Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.