Posters

Effect of corneal asphericity on underestimation in intraocular lens power calculation after myopic laser in situ keratomileusis

Poster Details

First Author: K.Minami JAPAN

Co Author(s):    Y. Mori   K. Miyata   K. Kamiya   K. Shimizu           

Abstract Details

Purpose:

Change in keratometry is considered as main factor of underestimating intraocular lens (IOL) power in an eye after myopic laser in situ keratomileusis (LASIK), while corneal shape change to oblate profile. This retrospective study was to investigate the effect of corneal asphericity in IOL power calculation.

Setting:

Kitasato University and Miyata Eye Hospital, Japan

Methods:

Clinical records of 18 eyes of 18 patients that implanted IOL in cataract surgery after myopic LASIK were reviewed. Mean age was 58.8 ± 6.0 years at cataract surgery, and duration after LASIK was 9.4 ± 3.4 years. Manifest refractions spherical equivalent (pre-MRSE) and averaged keratometry (pre-K) before LASIK, change in keratometry from pre-K (ΔK), axial length (AXL), and corneal eccentricity (Ecc) before cataract surgery, and refractive error at 1 month postoperatively were recorded. Step-wise multiple regression analysis was conducted between refractive error and the LASIK-related factors whether Ecc was excluded or not.

Results:

Mean refractive error was 2.03 ± 1.06 D (0.23 to 3.58 D). When Ecc was not included, there were significant correlations with pre-K and ΔK (P<0.008, R2=0.76). This result indicated that refractive error associated with degree of myopia and an amount of correction. When Ecc was included in multiple regression analysis, a significant correlation was found with Ecc only (P<0.0001, R2=0.69).

Conclusions:

Multiple regression analysis results demonstrated that change in corneal shape to oblate profile would more influence in underestimation in SRK/T. Compensation of corneal asphericity would be important in IOL power calculation of eye after myopic LASIK.

Financial Disclosure:

NONE