光視症と閃輝暗点の診断と治療

Diagnosis and treatment of cerebral photopsia

　光視は飛蚊症と明確に鑑別されねばならない。更に，光視は末梢性と中枢性に分類される。前者は狭義の光視症であり，後者には閃輝暗点が含まれる。中枢性光視症は，後頭葉腫瘍，血管異常などによって起るが，器質病変のはっきりしないものもある。その一部にphenytoin療法が著効するものがあることを報告した。

Photopsia, photic sensation of the visual system, is induced by non-photogenic stimulation of the photoreceptor cells in the retina and by abnormal discharge of the visual cortex. The latter has been called scintillating scotoma. Cerebral photopsia can be caused by such abnormalities as vascular anomaly or tumor in the occipital lobe. Excluding these cases of known etiology, there remain those with symptomatic photopsia which is closely related with classic migraine. We treated 13 cases of symp-tomatic cerebral photopsia with systemic pheny-toin, 0.3g daily.