糖尿病性網膜症の黄斑部機能

Macular function in diabetic retinopathy

　糖尿病性網膜症の視機能異常には，綱膜症のみならず，視神経症による因子と思われる変化が含まれていた．これらの因子を分析し，網膜症早期の視機能変化と黄斑部浮腫の検出方法について検討した．

　黄斑部に浮腫のない群では，視力，photostress recovery timeはいずれも正常であったが，色覚異常を示す例が見られた．

　黄斑部浮腫のある群では，色覚異常の程度とともにphotostress recovery timeも延長していた．

　proliferative retinopathyでは，photostress recovery timeも著明に延長し，中心CFFの低下例が見られた．

　以上の点より，黄斑部浮腫群，特にproliferative retinopathyには視神経症による因子も関与していると考えられた．

A total of 60 eyes (34 cases) with diabetic retino-pathy were evaluated as to the macular function. Particular attention was paid to the relationship between fluorescein angiographic findings and mac-ular functions including visual acuity, photostress recovery time, flicker fusion frequency (CFF) and color vision using 100-hue test. The ages of the patients ranged from 35 to 60 years. The ocular media was clear in all the eyes. The visual acuity was 0.1 or more in all the cases. The series included 23 eyes without macular involvement, 23 eyes with fluorescein staining of the macular and 14 eyes in preproliferative or proliferative stage of retinopathy.In eyes without macular involvement, the visual acuity and macular function tests were normal except occasional impaired color sense. In eyes with macular edema, color sense abnormality became more pronounced together with photostress re-covery time. Eyes with proliferative retinopathy manifested considerable elongation of photostress recovery time and, occasionally, impaired CFF.

The present findings indicate that an impaired color sense is the initial functional lesion in early diabetic retinopathy and that the photostress recovery time reflects the state of macularedema. Optic neuropathy seemed to be a frequent feature of proliferative diabetic retinopathy.