焦点深度拡張型眼内レンズが視野感度へ及ぼす影響

Visual field sensitivity in eyes implanted with extended depth of focus intraocular lens

要約　目的：焦点深度拡張型眼内レンズ（IOL）であるTECNIS Symfony^®（AMO）が視野感度へ及ぼす影響について，回折型二焦点IOLおよび単焦点IOLと比較検討する。

対象と方法：白内障術後6か月以内に片眼の緑内障あるいは緑内障疑いのために，ハンフリー視野計（HFA）のSITA fast中心30-2を施行した症例のなかで，眼疾患を認めない僚眼を対象とした。HFAの各パラメータをTECNIS Symfony^®挿入眼（EDOF群）と回折型二焦点IOL挿入眼（回折群），単焦点IOL挿入眼（単焦点群）で比較検討した。

結果：EDOF群11眼，回折群23眼，単焦点群27眼が対象となった。MD値はEDOF群−0.11±0.49dB，回折群−1.29±0.53dB，単焦点群0.05±0.52dB，中心窩閾値は35.4±0.9dB，33.1±1.6dB，36.4±1.6dBで，ともに回折群で有意に低値を認め（p＜0.001），EDOF群と単焦点群の間に有意差はなかった。PSD値は，3群間に有意差がなかった。

結論：回折型二焦点IOLは視野感度を低下させるが，焦点深度拡張型IOLであるTECNIS Symfony^®は視野感度への影響が少ない可能性が示された。

Abstract　Purpose：To report the visual field sensitivity in eyes implanted with extended depth of focus intraocular lens（IOL）.

Cases and Method：This study was made on 61 eyes of 61 patients who received cataract surgery. Eleven eyes were implanted with extended depth of focus IOL（TECNIS Symfony^®）, 23 eyes were implanted with diffractive bifocal IOL, and 27 eyes with monofocal IOL. Visual field sensitivity was measured by Humphrey field analyzer using 30-2 Swedish interactive threshold algorithm.

Results：Reduction in visual field sensitivity averaged −0.11±0.49 dB in extended depth of focus IOL, −1.29±0.53 dB in diffractive group, and 0.05±0.52 dB in monofocal group. The foveal threshold was 35.4±0.9 dB, 33.1±1.6 dB, and 36.4±1.6 dB respectively. Both values were significantly lower in the diffractive group than others（p＜0.001）. There was no significant difference between extended depth of focus IOL and monofocal IOL. There was no significant difference among the 3 groups regarding pattern standard deviation.

Conclusion：This study shows that visual field sensitivity decreases by diffractive bifocal IOL and that it is less influenced by extended depth of focus IOL.