アクリル眼内レンズの術後の屈折度変化の検討

Changes in refraction in eyes implanted with acrylic intraocular lens

要約　目的：アクリル眼内レンズの術後予想屈折度の精度と術後屈折度の変化の報告。対象と方法：過去45か月間に小切開白内障手術を行い，術後2か月後まで経過を追えた237眼を対象とした。術後矯正視力が0.6未満と，乱視が±2D以上のものは除外した。術前の屈折予想にはSRK/T式を用いた。眼内レンズには4種類を用いた。結果：術前の予想屈折度と術後の屈折度との違いは，4種類すべての眼内レンズの90％以上が±1.0D以内にあり，眼軸長とは無関係であった。屈折度は術後1週目と2か月後とで有意差はなかった。結論：使用した4種類の眼内レンズではSRK/T式が有用であり，術後早期から安定した屈折度が得られる。

Abstract.　Purpose：To report the accuracy of SRK/T formula and stability of refraction after implantation of 4 types of acrylic intraocular lens（IOL）. Cases and Method：This retrospective study was made on 237 eyes that received microincision cataract surgery during a 45-month period and that could be followed up for 2 months or longer after surgery. Eyes were ruled out that had visual acuity of 0.6 or less and that had astigmatism of ±1.0 diopter. Eyes were implanted with either of 4 types of acrylic IOL. Results：Difference between predicted and actual postoperative refraction was within ±1.0 diopter in more than 90％ of eyes implanted with either type of IOL. The difference was independent of axial length. There were no differences between refraction one week and two months after surgery regarding each of 4 types of IOL. Conclusion：SRK/T formula is useful for each of 4 types of acrylic IOL. Postoperative refraction remains stable from early postoperative period.