黄斑円孔網膜剥離の発症因子に関する検討

Causative factors for retinal detachment with macular hole

　病的近視眼と特発性老人性の黄斑円孔眼，合計196名・211眼を対象とし，屈折度・後極部の近視性網脈絡膜萎縮の程度・後部ぶどう腫の有無・後部硝子体所見の4点より網膜剥離の発症頻度を検討した。近視の屈折度・網脈絡膜萎縮が強くなるにしたがって，および後部ぶどう腫が存在すると，網膜剥離の発症頻度は有意に高くなった。後部硝子体剥離との間には有意な関連性はなかった。豹紋状眼底のみ呈する段階で，網膜剥離の発症母地が出来上がり，近視性網脈絡膜萎縮が出現するとさらに発症頻度が高くなる。また，後部ぶどう腫が発育・増大するに伴って，近視性網脈絡膜萎縮は高頻度に出現し，さらに後極部の強膜の拡張に伴い，脈絡膜，網膜の三者の間に形態的な歪みが生じ，網膜剥離の発症を助長すると考えた。なお，後部硝子体剥離は網膜剥離の発症に関しては大きな役割を果たしていないと思われた。

We found, in an earlier study, similarities between senile and myopic macular hole regarding the preponderance of females, age of onset and the status of posterior vitreous detachment (PVD). We designed the present study to elucidate factors which cause retinal detachment in these two groups.

We evaluated 211 eyes, 196 patients, with macular holes in pathological myopia and with idiopathic senile macular holes seen by us during the foregoing 10-year period. The incidence of retinal detachment was 98% in myopia over -8.25D, 68% in myopia between -8.0D and-3.25D, and 1% in eyes under -3.0D.

Retinal detachment was found in 100% of eyes with widespread myopic chorioretinal atrophy, 91% of spotty and linear chorioretinal atrophy, 64% of myopic tigroid fundus, and in none of eyes without tigroid fundus. Retinal detachment was present in 96% of eyes with posterior staphyloma, and 8% without posterior staphyloma. Retinal detachment occurred in 56% of eyes with complete PVD, 53% of eyes with partial PVD, and 52% without PVD.

The incidence of retinal detachment was thus significantly correlated with degree of refractive error, myopic fundus changes, and posterior sta-phyloma (p＜0.05) and not with the status of PVD.

It was our impression that common causative factors are involved in both types of macular holes. The preponderance of retinal detachment in myo-pia may be attributed to the associated pathologi-cal posterior fundus changes.