The effect of removing running sutures on astigmatism after penetrating keratoplasty

To evaluate astigmatic change after removal of the double running sutures used in penetrating keratoplasty, all patients (N = 131) in the Michigan Corneal Transplantation Patient Registry, Ann Arbor, whose eyes were phakic after penetrating keratoplasty were evaluated. The primary reasons for surgery in this group were keratoconus (n = 44, 34%) and Fuchs' corneal dystrophy (n = 19, 15%). The average effect of 10-0 suture removal in 58 eyes with documented keratometry readings was a 0.30-diopter (D) decrease in astigmatism, with 59% showing 2 D or less of astigmatic change. In 83 eyes with keratometry readings before and after 11-0 suture removal, an average increase of 0.37 D of astigmatism was observed, with 81% showing less than 2 D of astigmatic change. In eyes that were highly astigmatic (greater than 6 D) before suture removal, a reduction in astigmatism exceeding 2 D was observed in 39% and 11% after 10-0 and 11-0 suture removal, respectively.