前嚢切開形状と眼内レンズの偏位

Dislocation of intraocular lens as related to the shape of anterior capsulorrhexis

　目的：白内障手術での前嚢切開の形状と眼内レンズ（IOL）の偏位との関係を検索する。

　対象と方法：アクリルIOLを嚢内に固定した症例で，術後3か月以上を経過した79眼を対象とした。前嚢がIOL光学部を全周で覆っている31眼と，一部分被覆している48眼である。偏位は前眼部画像解析システムで計測した。

　結果：IOL偏心量には両群間に差はなかった。IOLの傾き角は，全周被覆群1.69°，部分被覆群2.36°であり，両群間に有意差があった（p＝0.012）。部分被覆群では，IOLの傾き方向と前被覆方向に正の相関があった（p＜0.001）。

　結論：前嚢がIOLの光学部全周を覆わない場合，IOLは前嚢被覆方向に傾斜する。

Purpose: To evaluate the relationship between tilting and dicentration of intraocular lens (IOL) and the shape of anterior capsulorrhexis following cataract surgery.

Cases and Method: The cases comprised 79 eyes which underwent cataract surgery and implantation of intracapsularly fixated acrylic IOL more than 3 months before. The series comprised 31 eyes in which the edge of IOL optics was covered by the anterior capsule and 48 eyes in which the edge of IOL optics was incompletely covered. The tilting and decentration were analyzed by an anterior eye segment analysis system.

Findings: There was no difference in the amount of decentration between the two groups. The tilting averaged 1.69°in the former group and 2.36° in the latter. The difference was significant (p = 0.012) . In the incompletely covered group, there was a positive correlation between the direction of IOL tilting and that of center of the anterior capsule (p＜0.001) .

Conclusion: The IOL tilts forward in the direction of the center of anterior capsule when a part of the edge of IOL optics is not completely covered by the anterior capsule.