intraocular lens power calculation after keratorefractive surgery

purpose: to determine corneal power for intraocular lens (iol) power calculation in eyes with previous keratorefractive surgery. methods: in 13 eyes of 9 patients with previous keratorefractive surgery undergoing phacoemulcification, iol power was calculated using the clinical history method (chm) in one case, manual keratometry (mkr) in 2, simk in 3, and flattest k (topographically derived) in 7 cases. srk-t formula with applanation method was used. final refractions (se) are presented. results: patients included 7 male and 2 female subjects aged 51.2±9.3 (range 41-70 years). postoperative refraction was hyperopic (+1.5 d) in eyes with the chm, variable and unpredictable in cases with the mkr and simk and more desirable (-0.35±0.39 d) in cases of flattest k.  in this latter group the best postoperative refraction was achieved in cases which 0.5 to 1.00 d was added to the calculated iol power. conclusion: it seems using topographically derived flattest k for iol power calculation and adding 1.00 d to the calculated iol power in eyes with previous myopic-refractive surgery, and using the steepest k together with subtracting 1.00 d from the calculated iol power in eyes with previous hyperopic-refractive surgery is useful when pre-refractive surgery data are not available.