Background: Postoperative hyperopia is a frequent result of cataract surgery i n eyes after previous myopic keratorefractive surgery. One reason for the undere stimation of intraocular lens (IOL) power is the wrong corneal refractive power measurement obtained by keratometers and corneal topography systems after LASIK. The aim of this study was to compare the precision of measurements of three dif ferent keratometers after LASIK. Method: We studied 58 eyes of 34 refractive pat ients aged between 20 and 51 years. The preoperative measurements and the measur ements one month after LASIK were performed with the Keratometer (Zeiss), the corneal top ograph (EyeSys Technologies) and the IOL-Master (Zeiss). We compared our postop erative measurement results obtained with the three keratometers with the result s obtained by using the clinical history method (chm). Results: The smallest mea n deviation was achieved with the IOL-Master (measured mean±SD: 38.94±1.88 D, vs. chm: 38.35±2.13 D). The Keratometer (Zeiss)-showed a larger deviation (me asured: 39.12±1.76 D, chm 38.34±2.07 D) and the largest deviation was shown wi th the corneal topograph (measured: 39.84±1.85 D, chm: 38.86 ±2.10 D), which m easured in mean one diopter higher than what was obtained utilizing the chm. A p ositive correlation between corrected myopia and the postoperative difference be tween the measured and calculated value for each keratometer was found. Conclusi on: This study demonstrates that with common keratometers central corneal power is measured too high after LASIK. For IOL calculation in patients after LASIK, t he wrongly positive deviation from measured central corneal power has to be take n into account.u001a Background: Postoperative hyperopia is a frequent result of cataract surgery in eyes after previous myopic keratorefractive surgery. One reason for the underestimation of intraocular lens (IOL) power is the wrong corneal refractive power measurement obtained by keratometers and corneal topography systems after LASIK. aim of this study was to compare the precision of measurements of three dif ferent keratometers after LASIK. Method: We studied 58 eyes of 34 refractive pat ients aged between 20 and 51 years. The preoperative measurements and the measur ements one month after LASIK were performed with the Keratometer (Zeiss), the corneal topograph (EyeSys Technologies) and the IOL-Master (Zeiss). We compared our postoprative measurement results obtained with the three keratometers with the result s using by the clinical history method (chm) Results: The smallest mea n deviation was achieved with the IOL-Master (measured mean ± SD: 38.94 ± 1.88 D, vs. chm: 38.35 ± 2.13 D). The Keratometer (Zeiss) -showed a larger deviation (me asured: 39.12 ± 1.76 D, chm 38.34 ± 2.07 D) and the largest deviation was shown wi th the corneal topograph (measured: 39.84 ± 1.85 D, chm: 38.86 ± 2.10 D ), which m easured in mean one diopter higher than what was obtained utilizing the chm. A p ositive correlation between corrected myopia and the postoperative difference be tween the measured and calculated value for each keratometer was found. Conclusi on: This study demonstrates that with common keratometers central corneal power is measured too high after LASIK. For IOL calculation in patients after LASIK, t he wrongly positive deviation from measured central corneal power has to be taken n into account. u001a