Refractive outcome of single running suture adjustment in penetrating keratoplasty

To evaluate the effectiveness of single running suture adjustment in reducing postoperative astigmatism and improving visual acuity in patients who have undergone penetrating keratoplasty.

Eighteen eyes of 18 patients who underwent penetrating keratoplasty at the Department of Ophthalmology, Başkent University between May 1997 and December 2000 and who had an astigmatism over 2 diopters (D) at the fourth postoperative week were included. All eyes underwent suture adjustment at the fourth week and eight eyes with residual astigmatism above 3 D underwent a second adjustment at the eighth week. Final astigmatism and visual acuity findings were evaluated 28 weeks postoperatively.

The mean postoperative keratometric and refractive astigmatism were 5.76 +/- 0.88 D (range=4.50-7.76) and 5.22 +/- 0.78 D (range=4.0-7.0) at the fourth week, which were decreased to 2.82 +/- 0.99 D (range=1.25-4.62, p=0.0001) and 2.61 +/- 1.01 D (range= 1.0-4.5, p=0.0001) after suture adjustment, respectively. In eight eyes at the eighth week, a second suture adjustment reduced the average keratometric and refractive astigmatism from 3.86 +/- 0.65 D (range=2.75-4.62) and 3.81 +/- 0.44 D (range=3.25-4.50) to 2.33 +/- 0.91 D (range=0.87-3.50, p=0.012) and 2.06 +/- 0.68 D (range=1.0-2.75, p=0.011), respectively. At the 28th week, the average keratometric and refractive astigmatism levels for the entire cohort, which were 2.39 +/- 1.06 D (range=1.0-3.50) and 2.25 +/- 0.96 D (range=1.0-3.25), respectively, showed a statistically significant decrease when compared with the levels before the first suture adjustment (p=0.0001 for both data). The mean best-corrected visual acuity was 20/25 on the Snellen chart at the 28th week.

Postoperative adjustment of single running suture is a safe and effective way of reducing postkeratoplasty astigmatism.