特発性網膜上膜—後部硝子体分離898眼の臨床的検討

Idiopathic epiretinal membrane in 898 eyes with posterior vitreous separation

　後部硝子体分離898眼の細隙灯眼底検査により358眼（約40％）の後極部に網膜上膜を認めた．網膜上膜の存在頻度には性差がなかった．正視群での頻度は近視群に比較して約1.5倍高かった．網膜上膜は高齢になるほど多くみられ，60歳以上では50歳未満に比べて2-3倍の高率となり，硝子体分離の時期が遅いほど網膜上膜の発生の高いことが推測された．網膜上膜を程度により，1度a：孤立性で1／5乳頭径以下の斑点状の5個以内の透明な薄い膜（264眼），1度b；融合性あるいは多数個の透明な薄い膜（39眼），2度：網膜表層の皺襞形成を伴う薄い膜（31眼），3度；網膜表層あるいは全層の皺襞形成を伴う半透明状の肥厚した膜もしくは剥離した膜（24眼），に分類した．年齢，性差，屈折異常のいずれも単独では網膜上膜の程度とは明確な相関関係を示さなかった．しかし，60歳以上の正視群や，飛蚊症を自覚してからの期間が長い例では重症な網膜上膜が多く観察された．特発性網膜上膜は極めて高い頻度で認められ，加齢および後部硝子体分離の時期に関係して発生し，硝子体分離後の期間が網膜上膜の進行に重要であることが示唆された．

A consecutive series of 898 eyes with spontaneous posterior vitreous separation were evaluated as to the presence of epiretinal membranes. Goldmann three-mirror contact lens was used throughout. The series included 184 eyes in males and 714 in females. Epiretinal membrane was present in 358 eyes in the present series (40%)

The incidence of epiretinal membrane was not related with sex. It was twice as often in the age group over 60 as under 50 years. It was more frequent in emmetropic than in myopic eyes.

The severity of epiretinal membrane was tentatively classified into 3 grades. la : solitary or spotty, thin and transparent membrane (264 eyes). lb : blot-like thin and transparent membrane (39 eyes). 2 : thin mem-brane with surface wrinkling of the retina (31 eyes) . 3 : thick membrane with surface or full-thickness shrink-age of the retina (24 eyes).

The severity of membrane formation was not relatedeither with age, sex or the amount of refractive error. Severe epiretinal membrane occurred in a higher inci-dence in emmetropic eyes in subjects of 60 years in age or over. The duration after occurrence of spontaneous posterior vitreous separation was positively correlated with the severity of epiretinal membrane.

Rinsho Ganka (Jpn J Clin Ophthalmol) 40(7) : 793-798, 1986