外傷性視神経症の視野

The visual field in traumatic optic neuropathy

　外傷性視神経症にみられる視野欠損の様相は症例ごとに異なっており不規則なものが多く，それらの損傷部位は視神経管内とされているが，それ以外の部位の損傷によると思われる自験例16例について残存視野の状態とその経時的変化を調べ，視神経疾患に関するこれまでの知見をもとに各症例の損傷部位と病態について検討した。残存視野を5つのパターンに分け，それぞれ不規則欠損型6例，傍中心暗点型5例，消失型3例，鼻側欠損型1例および下方欠損型1例であった。下方欠損型の損傷部位は螢光眼底造影の結果から視神経乳頭付近で，その病態は血液循環障害であると考えられた。

Twenty-two consecutive cases of traumatic optic neuropathy were reviewed in terms of visual field defects. Six cases were excluded because of incomplete neuroophthalmologic examinations. The site of trauma was ipsilateral to the involved eye. Visual field defects in these cases ranged from normal to total. Motor vehicle accidents were the most common cause of injury. Optic canal fractures were demonstrated in five cases radiographically. There was evidence that the intracanalicular segments of the optic nerve were involved in most cases. One of the 16 cases showed an inferior altitudinal visual field defect. Fluorescein angiography disclosed a filling defect in the capillaries of the optic nerve head. This disruption of the posterior ciliary artery indicated for traumatic anterior ischemic optic neuropathy.

The severity of the head trauma was not directly proportional to the severity of visual field defects.