超音波乳化吸引術での20ゲージと21ゲージ手術の比較

Comparison of 20-gauge and 21-gauge ultrasound chip in phacoemulsification-aspiration surgery

要約　目的：20Gと21Gチップを用いた水晶体乳化吸引術の比較。対象と方法：それぞれ同じ術者が水晶体乳化吸引術を行った86眼を対象とした。43眼には3.0mmの角膜切開と20Gのチップ，他の43眼には2.3mmの角膜切開と21Gのチップを用いた。結果：超音波の平均出力は，20G群で24.9±5.9％，21G群で27.3±4.9％で，両群間に有意差があった（p＝0.0198）。手術時間，超音波作動時間，術後の角膜内皮減少率については両群間に差はなかった。術中の印象として，21G手術では破砕と吸引の効率が低く，ペダルを強く踏み込むために超音波の出力が大きくなった。結論：20Gと21Gチップを用いた水晶体乳化吸引術では，手術時間，超音波作動時間，術後の角膜内皮減少率につき，両術式の間に大差はなかった。

Abstract.　Purpose：To compare 20 G and 21 G ultrasound chip in phacoemulsification-aspiration surgery. Cases and Method：This study was made on 86 eyes that received cataract surgery by same surgeon. 20 G chip with 3.0 mm corneal incision was used in 43 eyes. 21 G chip with 2.3 mm corneal incision was used in the other 43 eyes. Results：Power of ultrasound averaged 24.9±5.9％ in 20 G group and 27.3±4.9％. The difference was significant（p＝0.0198）. There was no difference between the two groups regarding duration of surgery,application time of ultrasound,and postoperative decrease in corneal endothelial cells. There was a feeling that 21 G surgery resulted in lesser efficiency of phacoemulsification-aspiration needing greater ultrasound output. Conclusion：There was no major difference between 20 G and 21 G chip in cataract surgery.