Manually performed limbal relaxing incisions versus femtosecond laser-guided astigmatic keratotomy for correction of corneal astigmatism after phacoemulsification

Abstract

Purpose This study aimed to evaluate the safety and efficacy of manually performed limbal relaxing incisions (LRIs) compared with femtosecond laser-guided astigmatic keratotomy (FLAK) in the management of corneal astigmatism after phacoemulsification. Patients and methods This is a prospective, comparative, randomized, interventional study that was conducted from March 2018 to September 2022. It included 56 patients (74 eyes) who had corneal astigmatism after conventional phacoemulsification. They were classified into two groups. Group A included 34 patients (41 eyes) for whom manual LRIs using a diamond knife were performed and group B included 22 patients (33 eyes) for whom FLAK was performed. The preoperative evaluation included manifest refraction, uncorrected distance visual acuity, best corrected distance visual acuity, slit lamp examination of the cornea, intraocular pressure measurement, and fundus examination. Corneal astigmatism in diopters (D) was established by corneal tomography and Scheimpflug imaging (Pentacam). Postoperative follow-up visits were scheduled on the first day, at 1 week, 1 month, and 3 months after surgery. Postoperative evaluation included a slit lamp examination for the incisions, uncorrected distance visual acuity, manifest refraction, and Pentacam to evaluate corneal astigmatism. Results The mean topographic corneal astigmatism was reduced from 3.36±1.66 D to 1.07±1.11 D, 3 months postoperatively in the LRIs group with a statistically highly significant difference (P=0.000) and from 3.66±1.82 D to 1.19±1.26 D in the FLAK group with a statistically highly significant difference (P=0.000). The mean topographic corneal astigmatism 3 months postoperatively showed a statistically nonsignificant difference between the two groups (P=0.665). Although there was no statistically significant difference between the two groups, the mean arithmetic reduction of astigmatism was higher in the FLAK group (2.47 D) than in the LRIs group (2.29 D). The surgery was uneventful in 92.68% of the cases in group A with only 7.32% showing nonserious corneal perforation, while in group B, the surgery was uneventful in 97% of the cases with only 3% showing nonserious corneal perforation with a statistically nonsignificant difference between the two groups (P=0.431). Conclusion Both manually performed LRIs and FLAK were safe, predictable, and effective methods for correcting pre-existing or surgically induced corneal astigmatism after phacoemulsification with a nonsignificant difference in visual and corneal topographic outcomes between the two methods.