To compare the predictability of central corneal thickness (CCT) reduction in myopic patients undergoing femtosecond laser-assisted in situ keratomileusis (FS-LASIK) using the aberration-optimized (Triple-A) and topography-guided (TG) profiles on the MEL 90 platform. This study involved 82 patients, treating one eye with the Triple-A profile and the other with the TG profile on the MEL 90, with an average spherical equivalent of − 5.76 ± 2.02 D (Triple-A) and − 5.79 ± 1.90 D (TG). Refractive assessments were done preoperatively and at 1 day, 1 week, 1 month, and 3 months postoperatively. Achieved CCT reduction (via Pentacam) = CCTpre-op-CCTpost-op. The MEL 90 platform provided the predicted CCT reduction, and comparative statistical methods and linear regression analyses were conducted. The 3-month CCT reduction was underestimated by 5.18 ± 7.41 μm in the Triple-A group (P < 0.0001) and by 14.44 ± 10.10 μm in the TG group (P < 0.0001). The planned CCT reduction in the TG group was much smaller than that in the Triple-A group (P < 0.0001), yet the achieved reduction was greater (P = 0.034), mainly in moderate myopia (P = 0.012). Moreover, subgroup analyses indicated that these differences were present exclusively in moderate to high myopia. As the corrected refraction increased, the planned-achieved difference (PAD) also increased. For patients with moderate and high myopia, both Triple-A and TG profiles of FS-LASIK on the MEL 90 laser platform may underestimate the CCT reduction. TG LASIK does not save corneal tissue but even consumes more of it in moderate myopia.
Jiang et al. (Sun,) studied this question.