小切開創白内障手術後の角膜形状解析

Topographic analysis of corneal shape after small incision cataract surgery

　小切開創白内障手術後の角膜形状変化を，角膜形状解析装置を用いて検討した。対象は切開創幅5mmのインフィニティー（∞）縫合群21眼と，同じく切開創幅5mmの無縫合群20眼である。

　∞縫合群では，術後早期（1週）に切開創に相当する45°−135°方向にsteep化（角膜屈折力の増加）が生じ，その後垂直方向の強いflat化（角膜屈折力の減少）と水平方向の強いsteep化が生じた。この原因は，縫合による直乱視化と考えられた。無縫合群では，術直後に90°方向最周辺部のflat化が生じたが，その他の部位には大きな変化はみられなかった。術後中長期においては，90°方向最周辺部のflat化を代償する形で，角膜全体の軽微な倒乱視化が生じた。無縫合群におけるこれらの変化は，∞縫合群に比べて小さく，角膜形状は早期に安定する傾向にあった。

We evaluated the corneal topography after small incision cataract surgery with phacoemulsi-fication and intraocular lens implantation in 41 eyes. Two types of wound closure technique was used: infinity suture in 21 eyes and no-suture surgery in 20. In the infinity suture group, a significant steepening occurred in the superior cornea corresponding to the site of incision in the early postoperative period. A substantial flattening developed later along the vertical axis and concomitant steepening in other parts of the cornea. These changes seemed to be due to loosening of the sutures. In the no-suture group, the surgery was followed by flattening of the most peripheral part of the superior cornea close to the site of incision. This change was balanced by a subsequent against-the-rule shift of the other corneal areas. Overall changes in corneal curvature in the no-suture group was significantly smallelr and more transient than in the infinity suture group.