Analysis of Intraocular lens power calculation for eyes with previous myopic LASIK

PURPOSE: To evaluate the effectiveness of a manual keratometry (K) adjusted value for intraocular lens (IOL) power calculation in patients who underwent cataract surgery following previous myopic LASIK. METHODS: Sixteen eyes of 14 consecutive patients who underwent cataract surgery after previous LASIK were evaluated retrospectively. All IOL powers were calculated using an adjusted K value (K minus 1.0 diopter [D]) with the Binkhorst 11 formula aiming for -0.75 to -1.00 D final refraction. Additionally, the IOL power for each eye was retrospectively calculated using K, refractive-derived K, and adjusted K with the Binkhorst 11, Holladay 1, and SRK/T formulas. The final refraction was used as a criterion of accuracy of each approach. RESULTS: Uncorrected visual acuity >= 20/40 was achieved in 14 (87.5%) of 16 eyes. The mean postoperative spherical equivalent refraction was -0.41 +/- 0.57 D (range: +0.50 to -2.00 D). Twelve (75%) of 16 eyes were within +/- 0.50 D of emmetropia and 15 (94%) of 16 eyes were within +/- 1.00 D. No eye was > + 1.00 D. CONCLUSIONS: Using an adjusted K with the Binkhorst 11 formula, aiming for -0.75 to -1.00 D, and with the Holladay I formula, aiming for -0.50 to - 1.00 D, measuring K with a regular manual keratometer permits determination of an IOL power after myopic LASIK without the need of preoperative LASIK refractive data.