外傷性視神経乳頭離断の1例

A case of traumatic avulsion of optic nerve head

　2歳8か月男児が高さ2.5mの崖から転落して顔面と頭部を打撲し，即日受診した。左眼視力は0で，左眼角膜にびらんがあり，乳頭前に硝子体出血があり周辺部網膜の色調が蒼白で，網膜中心動脈閉塞症が疑われた。1年9か月後に硝子体出血と混濁は消退した。視神経乳頭は陥凹し，陥凹底に線維組織の増殖があった。蛍光眼底造影で網膜主幹血管の灌流があった。外傷性視神経乳頭離断と診断した。本症では受傷直後から眼底の精査が困難であり，重篤な視力障害が残る。外傷患者の診察では本症も考慮する必要がある。

　A 32-month-old male infant fell from a 250cm-high precipice and was hit on the head and face. When seen the same day,his left visual acuity was no light perception. His left cornea showed erosion. Vitreous hemorrhage was present anterior to the optic disc. The peripheral retina appeared discolored,suggesting central retinal artery occlusion. The vitreous hemorrhage became absorbed 21months later. The optic disc was excavated and was covered by proliferative tissue. Fluorescein angiography showed perfusion in major retinal vessels. The left eye was diagnosed with traumatic avulsion of optic nerve head. This condition is characterized by difficulty in funduscopy and by grave visual prognosis. It has to be kept in mind in examining injury-related patients after injury.