The effect of suture removal on postkeratoplasty astigmatism.

I followed up for a minimum of six months 439 eyes that had undergone corneal transplantation using a suturing technique consisting of eight interrupted 10-0 and a single, continuous, 16-bite 11-0 nylon suture. All sutures were removed from 188 eyes an average of 20 months after surgery. After suture removal, 64 corneas had an increase of astigmatism greater than 0.5 diopter, 79 eyes showed a decrease in astigmatism greater than 0.5 diopter, and 42 corneas had no change in astigmatism. The mean astigmatism before suture removal was 3.7 diopters, and the mean astigmatism after suture removal was 3.5 diopters. There was no apparent difference in postkeratoplasty astigmatism with donor corneal diameters 0.25 to 0.75 mm greater in diameter than the recipient diameters, or with different host diseases. The longer the sutures were left in place after surgery, the smaller the quantitative change in astigmatism after suture removal. The complications of this technique were no different from other currently used suture techniques.