Correction of high degrees of astigmatism following phacoemulsification using manual or femtosecond laser-guided limbal astigmatic keratotomy

Purpose To evaluate the safety and efficacy of manual limbal astigmatic keratotomy (AK) compared to femtosecond laser-guided limbal astigmatic keratotomy (FLAK) to correct corneal astigmatism more than 3 diopters (D) after phacoemulsification. Study design Prospective, comparative, randomized, interventional study. Patients and methods This prospective study included 35 patients (40 eyes) divided into two groups. Group A included 16 patients (20 eyes) who had received FLAK and group B included 19 patients (20 eyes) who had received manual limbal AK using a diamond knife. All patients were suffering from corneal astigmatism after conventional phacoemulsification. This study was conducted from April 2024 to January 2025. Corneal astigmatism was measured by corneal tomography and Scheimpflug imaging (pentacam). Results The mean topographic corneal astigmatism was reduced from 4.78±1.4 to 1.78±1.31 D 3 months postoperatively in the FLAK group with a statistically highly significant difference ( P <0.001) and from 4.93±1.03 to 1.98±1.31 D in the manual limbal AK group with a statistically highly significant difference ( P <0.001). The mean topographic corneal astigmatism 3 months postoperatively showed a statistically nonsignificant difference between the two groups ( P =0.608). Although there was no statistically significant difference between the two groups, the mean arithmetic reduction of astigmatism was 3 D in the femtosecond AK group, which was higher than the mean arithmetic reduction of astigmatism in the manual AK group, which was 2.95 D. The surgery was uneventful in both groups with no adverse events. Conclusion FLAK and manual limbal AK are safe, predictable, and effective methods for correcting preexisting or surgically induced high degrees of corneal astigmatism after phacoemulsification, with the possibility to correct up to 4 D of corneal astigmatism.