The effect of low predicted/calculated postoperative keratometry on corrected distance visual acuity after LASIK.

Purpose: To compare refractive outcomes of eyes with flat keratometry (K) to matched controls after myopic laser in situ keratomileusis (LASIK).

Setting: Boston Eye Group, Brookline, Massachusetts, USA.

Design: Retrospective review.

Methods: Eyes that had LASIK between December 2008 and December 2018 were retrospectively analyzed and matched based on calculated postoperative flat K values. Stratified candidate subgroups (K < 38.0 diopters [D]) were compared with control subgroups (K ≥ 38.0 D).

Results: The study comprised 160 eyes (80 candidates and 80 controls). Statistical analyses showed no significant differences between candidates and controls in preoperative corrected distance visual acuity (CDVA) (P = .150) or postoperative CDVA (P = .290). There were no significant differences in the amount of tissue ablated between all candidate and control subgroups. Similarly, there was no significant change between preoperative and postoperative CDVA between the different candidate and respective subgroups. Three (3.75%) of 80 candidate eyes versus zero control eyes lost 1+ lines of CDVA after surgery. There was no difference in CDVA lost between these groups (P = .2453).

Conclusion: There is no increased risk for loss of CDVA after LASIK attributable to flat K.