Intrastromal Corneal Ring Segment Implantation by Femtosecond Laser for the Correction of Residual Astigmatism After Penetrating Keratoplasty

Abstract

Purpose: To evaluate the safety and efficacy of intracorneal ring segments (ICRSs) aided by femtosecond (FS) laser for the correction of residual astigmatism after penetrating keratoplasty (PKP). Methods: This retrospective noncomparative study comprised 14 eyes of 14 patients with high astigmatism after PKP who had ICRS implantation by femtosecond laser. The study evaluated uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive astigmatism, and corneal maximum curvature. Results: The CDVA postoperatively improved after 3 months (P < 0.001) and 6 months (P < 0.001) compared with CDVA preoperatively. The CDVA at 3 months was similar to that at 6 months (P > 0.999) as well as the UDVA (P = 0.276). The preoperative astigmatism was higher than that after surgery (P = 0.001). The preoperative maximum curvature was higher than that of the postoperative maximum curvature (P < 0.001). Conclusions: The implantation of ICRSs using the femtosecond laser for residual astigmatism post-PKP was safe and showed satisfactory results. It reduced refractive astigmatism and maximum corneal curvature and improved UDVA and CDVA.