内頚動脈閉塞性病変に起因する虚血性網膜症に対するバイパス術の効果―眼動脈血流の解析から―

Abstract

We examined the role of the STA-MCA bypass for chronic ocular ischemic syndrome due to the internal carotid artery (ICA) occlusive diseases. We examined 44 patients having chronic ocular ischemic syndrome due to the ICA occlusive diseases treated with STA-MCA bypass. Their visual symptoms were decline of visual acuity in 31 cases, frequent amaurosis fugax in 6 cases and both in 7 cases. In each patient, the ophthalmic artery flow was examined with color Doppler flow imaging (CDF) providing the flow direction, waveform and peak systolic flow velocity (PFV) before, at 1 month, and 3 months after surgery. Ophthalmologic examinations such as the visual acuity, retinal artery pressure and optic fundus were also examined. CDF findings: 1) Preoperatively, 39 patients showed reversed ophthalmic artery flow (average PFV: -0.32±0.16 m/sec). The other 5 patients showed antegrade ophthalmic artery flow (average PFV: 0.09±0.03 m/sec). 2) At 1 month after bypass, 17 patients showed the antegrade ophthalmic artery flow. Two of them showed the normal ophthalmic artery flow. Average PFV in the patients with preoperatively reversed ophthalmic artery flow significantly rose to -0.09±0.22 m/sec (p Visual symptoms: During the follow-up period (mean 4.5 years), no patients complained of recurrent visual symptoms. At the final stage, visual acuity improved in 18 patients (47%) and did not worsen in any of the remaining 26 patients. Ophthalmologic examinations also improved during the follow-up period. STA-MCA bypass played a useful and important role for the improvement or prevention of progress of the ocular ischemic syndrome due to the occlusive ICA diseases, especially for patients showing reversed ophthalmic artery flow.