倒乱視白内障に対し過矯正Toric IOLを用いた乱視矯正の検討

Insertion of overcorrected toric intraocular lens in cataract surgery for against-the-rule astigmatism

要約　目的：倒乱視がある白内障眼に対し，意図的に過矯正になるようなトーリック眼内レンズ（IOL）を挿入した結果の報告。対象と方法：倒乱視がある白内障34眼に，AcrySof^®として推奨されるより1段階強いトーリックIOLを挿入し，1か月後の臨床所見を検索した。過去に推奨モデルを挿入した20眼と，その結果を比較した。結果：術後の残余乱視軸は，倒乱視5眼，直乱視12眼，斜乱視17眼であった。術後の裸眼視力は平均値logMAR 0.19，矯正視力はlogMAR －0.01，自覚円柱度数は0.69D，自動屈折計による円柱度数は0.99Dであり，いずれも術前よりも有意に改善した。結論：倒乱視がある白内障眼に対し，意図的に1段階の過矯正になるようなトーリックIOLを挿入し，術後の残余倒乱視が軽減した。

Abstract.　Purpose：To review the outcome of cataract surgery in eyes with against-the-rule astigmatism inserted with higher-power toric intraocular lens（IOL）. Cases and Method：Cataract surgery was performed on 34 eyes with against-the-rule inverse cataract. They were inserted with AcrySof^® toric IOL that was stronger by one step than recommended. The outcome was evaluated one month after surgery and was compared with another series of 20 eyes that received insertion of toric IOL as recommended. Results：Residual astigmatism was oblique in 17 eyes, direct in 12 eyes, and against the rule in 5 eyes. Uncorrected visual acuity averaged logMAR 0.19, corrected visual acuity averaged logMAR －0.91, subjective power of cylinder averaged 0.69 diopters, and objectively measured cylinder averaged 0.99 diopters. All the values showed significant improvements when compared with the preoperative ones. Conclusion：Reduced residual astigmatism resulted after insertion of overcorrected toric intraocular lens in cataract surgery on eyes wit against-the-rule astigmatism.