エキシマレーザー近視矯正術後の白内障手術における眼内レンズ度数決定

Intraocular lens power calculation in eyes with previous keratorefractive surgery

要約　目的：屈折矯正手術の既往がある眼での白内障手術後の屈折の報告。対象と方法：過去に近視に対する屈折矯正角膜手術を受けた16例23眼に白内障手術を行った。男性21眼，女性2眼で，年齢は38～77歳，平均58歳である。眼内レンズ屈折値の予測には全例で手術直前の8種類の計測値を用い，うち10眼では屈折手術前の計測値を合わせて使用した。結果：全例で裸眼視力は改善し，全例で0.9以上の矯正視力が得られた。屈折矯正視力前の値を使用したCamellin-Calossi式で白内障手術後の屈折誤差の絶対値の平均値が0.38±0.29と良好な精度が得られたが，他の方法と比較して有意差はなかった。結論：屈折矯正手術の既往がある眼での白内障手術での眼内レンズ屈折値の決定では，白内障手術直前の値だけによる予測と，屈折矯正手術前の値を加味した予測とで，結果に有意差はなかった。

Abstract.　Purpose：To report the state of refraction after cataract surgery in eyes with previous keratorefractive surgery. Cases and Method：This retrospective study was made on 23 eyes of 16 cases that had received meratorefractive surgery in the past and that received cataract surgery with intraocular lens（IOL）implantation. The series comprised 21 male and 2 female eyes. The age ranged from 38 to 77 years, average 58 years. Eight different formulas were used in predicting the IOL power in all the eyes. Additionally, data before refractive surgery was used in 10 eyes in calculating the IOL power. Results：Uncorrected visual acuity improved in all the eyes. Corrected visual acuity was 0.9 or better in all the eyes. Discrepancy between the predicted and actual refraction was the smallest when using the Camellin-Calossi formula that showed 0.38±0.29 as average of absolute value. There were no significant differences in the outcome among the 8 formulas. Conclusion：No significant differences were present in the outcome of cataract surgery whether the IOL power was calculated using any of 8 formulas or additionally using data before keratorefractive surgery.