Intraocular Lens Power Calculation in High Myopic Eyes With Previous Radial Keratotomy

Abstract

PURPOSE: To determine an accurate method of intraocular lens (IOL) power calculation in highly myopic eyes with previous radial keratotomy (RK). METHODS: Five eyes that had undergone RK with preoperative myopia >-14.0 diopters (D) were studied retrospectively. The keratometric values obtained with the clinical history method, contact lens over-refraction method, conventional keratometry, adjusted keratometry, and Orbscan II were compared to the true keratometric value calculated retrospectively with the SRK/T formula. RESULTS: The true keratometric value was closest to that from the contact lens over-refraction method in one eye and to the flatter keratometric value between simulated keratometry (Sim K) and the 3-mm diameter central zone mean keratometric value obtained with axial keratometric power map of Orbscan II in four eyes. CONCLUSIONS: The flatter keratometric value between Sim K and the 3-mm zone mean keratometric value from Orbscan II was closest to the true postoperative RK keratometric value of the central cornea.