慢性進行性に経過した後部虚血性視神経症の2症例

Two cases of chronic posterior ischemic optic neuropathy

　我々は突発性発症を見ず，慢性進行性に視力低下，視野狭窄をきたした後部虚血性視神経症の2症例を経験した．いずれも，Oculo-cerebro-vasculo-metry （OCVM）で異常が捕えられ，血管撮影にて内頸動脈の狭窄が証明された．

　うち1例については，眼動脈循環を改善させる目的で，浅側頭動脈-涙腺動脈吻合術を施行し，一時的ではあったが，症状の進行を見ず，ある程度の効果が認められた．

　眼循環不全が疑われる場合，内頸動脈の検索が必要となるが，血管撮影を施行する前に非侵襲的な診断法であるOCVMを施行することが有用であると考えられた．

We observed chronic posterior ischemic optic neuropathy in 2 males, aged 50 and 54 respectively. In both cases, slowly progressive visual distur-bances set in without sudden episodes of loss of vision. One case resulted in severely impaired vision in one eye and the other in bilateral visual loss. Oculocerebrovasculometry (OCVM) showed abnor-malities in the pulse/intraocular pressure relation-ship in both cases, suggesting insufficient ocular blood flow. Cerebral angiography also showed stenosis of internal carotid arteries.

A bypass surgery was performed in one case between the superficial temporal artery and the lacrimal artery to improve the ocular circulation.Studies with OCVM one week later showed im-proved ocular circulation. The vision remained stable for the following 17 months. Thereafter, the vision failed again, apparently due to impatency of anastomosed vessels.

In cases with suspected ischemic optic neuropath-y, OCVM promises to be of value as a non-invasive diagnostic technique.

Rinsho Ganka (Jon J Clin Ophthalmol) 42(7) : 879-882, 1988