Accurately Predicting Intraocular Lens Power For Cataract Surgery In Patients With Previous Lasik Surgery.

Background: Calculating intraocular lens (IOL) power for cataract surgery implants in
patients with previous LASIK surgery is inaccurate at best. Research is lacking in this
area due to the major focus on post-cataract surgery IOL power failures (greater than lD
of refractive error after IOL implantation) calculated in patients with previous refractive
surgery. Methods: A comprehensive study ofkeratometry readings from 122 patients taken prior to refractive surgery and then after refractive surgery is used to calculate IOL's. It is already known that for every Diopter of refractive error corrected by LASIK, the keratometry reading changes by 0.75D. Results: An IOL was calculated using preand post-refractive surgery K-readings and the change in IOL power was plotted against the pre-refractive surgery myopic spherical equivalent, resulting in a positive correlation that agrees with previous research (p=O.OOl). Also, post-refractive surgery K-readings were plotted against the change in IOL power resulting in a negative correlation (p=O.OOl). Conclusions: It is possible to use post-LASIK keratometry readings and the change in IOL power from the graph to calculate the accurate post-LASIK IOL power. The table presented in this paper can be used to accurately calculate an IOL in postLASIK patients by utilizing the corrective factor.