Against-the-rule astigmatism judged at one week after phacoemulsification and aspiration procedures

To determine the characteristics of astigmatism 1 week postoperatively or whether the final astigmatism is predictable from that present 1 week postoperatively, we analyzed 544 postcataract against-the-rule (AR) cases of astigmatism among 1,649 standard phacoemulsification cataract operations, all utilizing 10-0 Mersilene in double-running fashion. Postoperative AR astigmatism < or = 1.0 dpt increased markedly 1 week postoperatively (2.72 +/- 0.09 dpt) but decreased 6 months postoperatively. However, in postoperative AR astigmatism > 2.0 dpt, the increase 1 week postoperatively was not as great (2.16 +/- 0.13 dpt) but tended to continue to increase even 6 months postoperatively, with a flatter corneal curvature being the responsible factor. Eyes with less astigmatism 1 week postoperatively showed exacerbation of final astigmatism 6 months postoperatively. This course was different from that of small incision cataract surgery.