3焦点と焦点拡張型の多焦点眼内レンズにおける術後視機能特性

Characteristics of visual function with trifocal and extended depth-of-focus IOL

要約　目的：回折型3焦点眼内レンズ（IOL），焦点深度拡張型（EDOF）IOLを両眼に挿入した症例における術後の見え方の特性と患者満足度を後ろ向きに検討した。

対象と方法：対象は，当院にて2019年末までに白内障手術時に3焦点あるいはEDOF IOLが両眼挿入され，術後自覚屈折値が±1.0D以内の症例である。術後1〜3か月の両眼視下での裸眼・遠方矯正下視力（距離：0.3，0.4，0.5，0.6，0.7，1.0，5.0m），眼鏡装用，コントラスト感度，満足度，光障害の有無を調べた。

結果：3焦点群は37例，EDOF群は64例であった。各群において，裸眼・遠方矯正下視力とも0.5m以遠，0.7m以遠で平均1.0以上が得られ，3焦点群は0.3〜0.5mで，EDOF群は1.0m以遠で有意に良好であった。眼鏡装用は，各群86.5％，42.1％で不使用であり，EDOF群の49.1％は手元視用であった。コントラスト感度は空間周波数12cpd，18cpdにおいてEDOF群が良好であった。満足度，光障害の有無については，EDOF群は49.1％が手元での見え方に不満，71.9％はコントラスト低下がないと回答した。

結論：3焦点群は遠中近距離で生活に必要な視力が得られ，EDOF群は中間以遠でより良好な視機能が得られた。各IOLの特性を理解し，症例に適したIOLの選択が重要と考える。

Abstract　Purpose：To compare the characteristics of visual function and patient satisfaction after bilateral implantations of diffractive trifocal and extended depth-of-focus（EDOF）intraocular lenses（IOLs）.

Subjects and methods：Clinical records of patients who underwent bilateral cataract surgery with implantation of a trifocal（trifocal group）or EDOF（EDOF group）IOL at our institution, until the end of 2019, and who had postoperative subjective refractions within±1.0D. Binocular uncorrected and corrected visual acuity（distance：0.3, 0.4, 0.5, 0.6, 0.7, 1.0, and 5.0 m）, spectacle usage, contrast sensitivity, patient satisfaction, and dysphotopsia were assessed 1-3 months after surgery.

Results：There were 37 and 64 patients in the trifocal and EDOF groups, respectively. In each group, the mean uncorrected/corrected visual acuities were better than 1.0（Snellen notation）at 0.5 m/0.7 m and beyond, and were significantly better in the trifocal group at 0.3-0.5 m, and in the EDOF group at 1.0 m and beyond after surgery. Spectacle independence was achieved in 86.5％ and 42.1％ of cases, respectively, and 49.1％ of the EDOF group used spectacles for near vision. Contrast sensitivity in the EDOF group was better at spatial frequencies of 12 cpd and 18 cpd. Questionnaire results showed that 49.1％ of the EDOF group were dissatisfied with near vision, but no reduction in contrast sensitivity was reported by 71.9％.

Conclusion：Binocular visual acuity was obtained at the near to distance range with trifocal IOLs, while the EDOF IOLs provided preferred visual function at the intermediate range and beyond. It is important to understand the characteristics of each IOL and select the appropriate IOL for the individual patient.