Relaxing incisions reduce postop astigmatism

Relaxing incisions are a safe and effective method for reducing postoperative astigmatism and help improve visual acuity (VA), according to a study published in the March issue of the Journal of Refractive Surgery.

Margareta Claesson, MD and John Armitage, PhD, from the Sahlgrenska University Hospital, Sweden and the University of Bristol, UK, respectively, conducted a study to determine the impact of relaxing incisions for correcting postoperative astigmatism following penetrating keratoplasty.

Data was collected through the Swedish Corneal Transplant Register and, of the 1,161 grafts with complete two-year follow-up, 131 underwent relaxing incisions. Stepwise multiple regression was used to determine the factors that influenced the extent of astigmatism. The change in astigmatism brought about by relaxing incisions was evaluated by subtraction and vector analysis.

In patients who underwent relaxing incisions, astigmatism was reduced from 8.40 D to 3.80 D. The mean difference by subtraction was 4.50 D and vector analysis showed the overall reduction of astigmatism induced by surgery to be 7.90 D. Compared with grafts with no refractive surgery, a trend was seen that suggested corrected VA was improved following relaxing incisions.

It was concluded that relaxing incisions are safe and effective as a method of reducing postoperative astigmatism and may even help improve VA in some cases.