Change in keratometry after myopic laser in situ keratomileusis and photorefractive keratectomy

Abstract

Purpose: To compare the change in keratometry (K), spherical equivalent (SE), and visual acuity after myopic laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK).

Setting: Academic tertiary care center.

Design: Retrospective review.

Methods: The postoperative K, SE, and uncorrected and corrected distance visual acuities were measured 6 months, 9 months, 1 year, 2 years, 3 years, 4 to 5 years, 6 to 7 years, and 8+ years postoperatively. A difference (Δ) for each variable was calculated from its 6-month postoperative baseline. The rates of change were grouped based on the magnitude of myopic correction (0.00 to 2.99 diopters [D]; 3.00 to 5.99 D; 6.00 to 8.99 D), type of surgery (LASIK versus PRK), and age (<34 years; 34 to 45 years; >45 years).

Results: Statistically significant differences were found in the rates of change between low and moderate corrections to high corrections for ΔKavg (P=.0472 and P=.0091, respectively) and ΔSE (both P<.0001). Statistically significant differences were found in the rate of change in ΔKavg between all 3 ages groups (P=.0330, P=.0051, and P<.0001) and in ΔSE between ages less than 34 years and 34 to 45 years to ages over 45 years (P=.0158 and P=.0015, respectively). There was no significant difference in the rate of change in ΔKavg and ΔSE between LASIK and PRK (P=.3599 and P=.9403, respectively).

Conclusion: There was keratometric and refractive regression for myopic LASIK, with the rate of regression depending on treatment magnitude and age.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.