Effect of STA-MCA bypass for ocular ischemic syndrome due to occlusive internal carotid artery diseases

The authors examined the effect of superficial temporal artery-middle cerebral artery (STA-MCA) bypass for chronic ocular ischemic syndrome (OIS) due to occlusive internal carotid artery (ICA) diseases. We retrospectively examined the result of STA-MCA bypass in 49 patients with chronic OIS due to occlusive ICA diseases. Symptoms were a decline in visual acuity in 32 patients, frequent amaurosis fugax in 8 patients, and 9 patients showed both symptoms. Preoperatively, the flow directions of the ophthalmic artery were reversed in 45 patients and antegrade in 4 patients. The average peak systolic flow velocity (PFV) of the ophthalmic artery was -0.37 m/sec. At one month after bypass, 17 patients showed the antegrade ophthalmic artery flow. Mean PFV of the ophthalmic artery significantly rose to -0.12 m/sec (p<0.05). At three months after surgery, 26 patients showed the antegrade flow. Mean PFV of the ophthalmic artery significantly increased to 0.01 m/sec (p<0.05). During the follow-up period (mean 4.9 years), visual acuity improved in 23 patients (47%) and ceased to worsen in the remaining 26 patients. STA-MCA bypass was useful in improving and preventing OIS due to occlusive ICA diseases. (author)