Abstract
Purpose: :
To evaluate the effect of limbal relaxing incisions(LRIs) on the corneal astigmatism in cataract surgery
Methods: :
25 eyes in 20 patients who have 1.5 diopters(D) or more in topography were underwent limbal relaxing incisions(LRIs) during uneventful cataract surgery. Single or paired LRIs were performed on the steepest axis, and the degrees of arc were determined using the Gills and Gayton’s modified nomogram. The clear corneal wound was also made on the steepest axis. Uncorrected visual acuity (UCVA), best corrected visual acuity(BCVA), manifest refraction, corneal astigmatism on topography were checked preoperatively and 1 month postoperatively. Naeser’s polar value analysis was used to assess the efficacy of LRIs. The efficacy of LRIs according to depth and number of LRIs was assessed.
Results: :
Mean depth of LRIs and degrees of arc were 637 ± 31um(87.1 % of corneal thickness) and 56.84 ± 19.68, respectively. The mean preoperative and postoperative UCVA(log MAR) was 1.25 ± 0.43 and 0.51 ± 0.37, respectively (P<0.001), and the mean BCVA(log MAR), 0.42 ± 0.20 and 0.09 ± 0.12 (P<0.001). The mean preoperative and postoperative refractive astigmatism was 3.18D ± 1.80 and 1.61D ± 0.78, respectively (P=0.002), and the Sim K astigmatism in corneal topography, 2.71D ± 1.35 and 1.83D ± 0.75, respectively (P=0.029). There was no significant difference of corrected astigmatism between the LRI depth of less than 85% of corneal thickness and the depth of more than 85%. The reduction effect of Single incision was not significantly different from that of double incision.
Conclusions: :
Limbal relaxing incisions which were designed to 2 hours and 87% of depth showed about 50% of reduction effect for corneal astigmatism when combined in cataract surgery, irrespective of single or paired LRI.
Keywords: astigmatism • cataract • refractive surgery: other technologies