非球面および球面IOL挿入眼の高次波面収差の比較

Higher-order wavefront aberrations in eyes implanted with aspheric or spheric intraocular lens

目的：非球面と球面眼内レンズ（IOL）挿入眼の高次波面収差の解析と比較。対象と方法：白内障がある20例の両眼に超音波乳化吸引術を行い，1眼に球面IOL，他眼に非球面IOLを挿入した。高次波面収差測定で得られた全屈折をZernike多項式に展開し，コマ収差，球面収差，全高次収差を定量的に解析し，そのRMS（root mean square）を比較した。瞳孔径は3mmと5mmに設定した。結果：瞳孔径3mmでは，非球面IOL挿入眼の球面収差が球面IOL挿入眼よりも有意に低値であった。瞳孔径5mmでは，非球面IOL挿入眼の球面収差と全高次収差が球面IOL挿入眼よりも有意に低値であった。狭義の四次球面収差（C⁰₄）は，瞳孔径3mmと5mmのいずれについても，非球面IOL挿入眼のほうが球面IOL挿入眼よりも有意に低値であった（p＜0.05）。結論：非球面IOL挿入眼では，球面IOL挿入眼よりも球面収差を軽減することが可能である。

Purpose：To compare higher-order wavefront aberrations in eyes implanted with aspheric or spheric intraocular lens（IOL）. Cases and Methods：Twenty cataract patients underwent phacoemulsification-aspiration. In each patient,one eye was implanted with spheric IOL and the fellow eye with aspheric IOL. These eyes were evaluated by a wavefront analyzer. Higher-order aberrations were expanded into Zernike's polynomial expression. Coma,spherical aberration,and total higher-order aberration were compared as root mean square（RMS）. Results：At pupil diameter of 3 mm,the spheric aberration was significantly less in eyes with aspheric than sheric IOL. At pupil diameter of 5 mm,spheric and total higher-order aberration was significantly less in eyes with aspheric than sheric IOL. At both pupil sizes,the fourth-order spheric aberration was significantly less in eyes with aspheric than sheric IOL（p＜0.05）. Conclusion：It is possible to reduce spheric aberration by using aspheric instead of spheric IOL.