Purpose: To compare the effects of performing a single limbal relaxing incision (LRI) combined with a clear corneal incision on a corneal astigmatism with that of paired LRIs in cataract surgery.
Methods: Medical records for 25 eyes in 20 patients who had undergone LRIs during cataract operations for with-the-rule astigmatism of 1.5 diopters (D) or more in topography were retrospectively reviewed. Single or paired LRIs were assigned randomly and were performed on the steepest axis; the degrees of arc were determined using the modified Gills nomogram. A clear corneal wound was made on the steepest vertical axis. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, and corneal astigmatism on topography were evaluated preoperatively and one month postoperatively. Naeser's polar value analysis was used to assess the efficacy of the LRIs.
Results: The mean depth of the LRIs and degrees of arc were 620+/-31 microm (87.1% of corneal thickness) and 56.84+/-19.68 degrees , respectively. The mean postoperative UCVA and BCVA (log MAR) were significantly improved (0.51+/-0.37 and 0.09+/-0.12, respectively) (p<0.05). Average refractive and corneal astigmatisms were significantly reduced by 49.4 percent and 32.4 percent, respectively (p<0.05). The single LRI combined with clear corneal incision showed reduced efficacy in refractive astigmatism by 47 percent, which is similar to that of paired LRIs where a 48 percent reduction in efficacy was seen.
Conclusions: The short-term effects of a single LRI combined with clear corneal incision on a corneal astigmatism appears to be as effective as performing paired LRIs when combined with cataract incision.
Keywords: Astigmatism; Cataract surgery; Clear corneal incision; Limbal relaxing incision.