視覚障害をきたす原因疾患の推移

Changing trends in the cause of severe visual impairment

　少なくとも片眼の視力が0.1未満である症例の頻度と具体像を，当科外来初診患者について検索した。1986年までの5年間をI群，2001年までの3年間をⅡ群として比較した。視覚障害の原因疾患では，両群とも糖尿病網膜症が最も多く，その頻度は1群で14.7％，Ⅱ群で20.4％であった。加齢黄斑変性症は，I群にはほとんどなく，Ⅱ群ではその第2位の9.2％に増加していた。老人性白内障は，I群では9.4％（第2位）であり，Ⅱ群では3.4％（第10位）に減少していた。両眼とも0.01以下の高度視覚障害の原因は，両群とも糖尿病網膜症が第1位であり，I群で23.1％，Ⅱ群で24.5％であった。

We reviewed the incidence and clinical features of diseases causing visual impairment to 0.1 or less at least in one eye among patients in our outpatient department. Patients seen during 5 years through 1986 were defined as group 1. Those seen during 3 years through 2001 were defined as group 2. In both groups, diabetic retiopathy was the most frequent cause of visual impairment. Its incidence was 14.7% in group 1 and 20.4% in group 2. Age-related macular degeneration was almost absent in group 1. It became the second most frequent cause in group 2 at 9.2%. Senile cataract was the second most frequent cause in group 1 at 9.2 %. It ranked as the tenth in group 2 at 3.4%. When severe visual impairment was defined as visual acuity of 0.01 or less in both eyes, diabetic retinopathy was its most frequent cause in both groups. Its Inci-dence was 23.1% in group 1 and 24.5% in group 2.