Long-Term Outcomes of Post-Penetrating Keratoplasty Astigmatic Keratotomy Performed Using 30 kHz Femtosecond Laser Flap Mode Software vs 150 kHz Femtosecond Laser Enabled Astigmatic Keratotomy Software

Abstract

Purpose: To assess the long-term outcomes of astigmatic keratotomy (AK) performed with two different techniques in patients with post-penetrating keratoplasty (post-PK) residual astigmatism. Methods: This retrospective comparative case series was performed at Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA. Patients who underwent post-PK AK performed using either 30 kHz femtosecond laser flap mode software (IntraLase/AMO, Irvine, CA)-Group 1-or using 150 kHz femtosecond laser enabled AK software (IntraLase/AMO, Irvine, CA)-Group 2-to create two anterior arcuate corneal incisions were included in this study. Preoperative and long-term postoperative follow-up data, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and spherical equivalence (SE) were analyzed. Results: In group 1 (n=5), the difference in pre- and post-operative UDVA (0.97 ± 0.29 LogMAR to 0.68 ± 0.40 LogMAR, p=0.13), CDVA (0.28 ± 0.27 LogMAR to 0.47 ± 0.48 LogMAR, p=1), SE (-2.0 ± 3.0 diopters (D) to -1.8 ± 1.8 D, p=0.88) were not statistically significant, although UDVA and SE showed clinical improvement. In group 2 (n=6), the difference in pre- and post-operative UDVA (1.20 ± 0.14 LogMAR to 0.82 ± 0.62 LogMAR, p=0.19), CDVA (0.58 ± 0.32 LogMAR to 0.34 ± 0.31 LogMAR, p=0.25), SE (-2.3 ± 4.7 D to -2.9 ± 4.4 D, p=0.25) were not statistically significant. There was no statistical difference regarding postoperative UDVA (p=0.85), CDVA (p=0.93), SE (p=0.51) and surgically induced astigmatism (p=0.13) between the 2 groups. Conclusion: AK performed with both techniques is a safe procedure to correct post-PK residual astigmatism. Both techniques yielded comparable results.