前囊切開時の水晶体動揺を指標にしたZinn小帯脆弱度分類の試み

Tentative classification of fragility of the zonule based on floppiness of the lens during capsulorrhexis

要約　目的：白内障手術中の円形前囊切開時の水晶体動揺と前囊の皺襞に基づくZinn小帯の脆弱度の分類。症例と方法：水晶体乳化吸引術と眼内レンズ挿入術を行った687眼を対象とした。Zinn小帯の脆弱度は，前囊切開の開始時に水晶体動揺と皺襞がないもの（0度），動揺と皺襞があるもの（1度），引き裂き時に皺襞があるもの（2度），メスと高粘度の粘弾性物質を必要とするもの（3度），これに加えて水晶体の振盪と脱臼があるもの（4度）とした。結果：133眼が0度，533眼が1度，10眼が2度，2眼が3度，9眼が4度と判定された。水晶体乳化吸引術中に水晶体囊を支持する器具と眼内レンズ縫着術を必要とした例は，0度ではいずれも0％，1度ではそれぞれ0.1％，2度では80％と10％，3度では100％と0％，4度ではいずれも100％であった。結論：白内障手術での円形前囊切開時の水晶体動揺と前囊の皺襞に基づくZinn小帯の脆弱度の分類は，器具と術式の選択に有用である。

Abstract.　Purpose：To classify the fragility of zonule based on floppiness of the lens and formation of folds during anterior capsulorrhexis in cataract surgery. Cases and Method：This study was made on 687 eyes that received phacoemulsification-aspiration with intraocular lens implantation. Fragility of the zonule was classified into five stages：no movement or folding at the start of puncture of the capsule（grade 0）, lens movement and folding（grade 1）, folding during capsulorrhexis（grade 2）, surgical procedure needing use of knife and viscoelastic material（grade 3）, and additional presence of floppy lens or luxation（grade 4）. Results：Eyes in the present series were classified as grade 0 in 133 eyes, grade 1 in 533 eyes, grade 2 in 10 eyes, grade 3 in 2 eyes, and grade 4 in 9 eyes. Capsular stabilization device and secondary suture of intraocular lens were necessary in none in grade 0, in 0.1％ each in grade 1, in 80％ and 10％ respectively in grade 2, in 100％ and 0％ respectively in grade 3, and in 100％ each in grade 4. Conclusion：Classification of fragility of zonule may be useful in the selection of capsular stabilization device and procedure of cataract surgery.