単焦点眼内レンズ挿入眼における偽調節に関与する因子の検討

Apparent accommodation in monofocal pseudophakic eyes

要約　目的：偽調節関連因子についての報告。

対象と方法：同一の単焦点眼内レンズを挿入した遠見矯正視力1.0以上の36例64眼を対象とした。男性11例，女性25例で，年齢は平均74.0±7.3歳である。主観的偽調節量は近見視力検査にて評価し，他覚的偽調節量は他覚的屈折変化，瞳孔径変化，角膜屈折力勾配，MTF値にて評価した。

結果：偽調節量は0.15〜1.0（0.61±0.20）logMARであった。角膜屈折力勾配と偽調節量間には弱い正の相関が認められた（r＝0.428，p＜0.05）。瞳孔径と偽調節量間には極弱い負の相関がみられた（r＝−0.266，p＜0.05）。調節負荷時の他覚的屈折変化は0.07±0.20D（n＝25）であり，ほとんど認められなかった。

結論：偽調節には角膜の多焦点性が関与する。

Abstract　Purpose: To report apparent accommodation in eyes inserted with monofocal intraocular lens.

Cases and Method: We reviewed the medical records of 64 eyes of 36 patients who received cataract surgery with insertion of monofocal intraocular lens. The series comprised 11 males and 25 females. The age averaged 74.0±7.3 years. Evaluation of apparent accommodation was based on visual acuity in the near. Patients also received refractive measurements, pupil diameter, corneal topography and values of modulation transfer function, in order to ascertain associations with apparent accommodation. Visual acuity was evaluated as logMAR.

Results: Apparent accommodation ranged from 0.15 to 1.0, average 0.61±0.20. A weak correlation was present between apparent accommodation and mean corneal multifocality（r＝0.428, p＜0.05）. A very weak negative correlation was present between apparent accommodation and mean pupil diameter（r＝−0.266, p＜0.05）. Refraction changed by an average of 0.07±0.20D（n＝25）during accommodation.

Conclusion: Apparent accommodation in monofocal pseudophakic eyes is related to multifocality of the cornea.