PREOPERATIVE KERATOMETRY MEASUREMENTS USING PARTIAL COHERENCE LASER INTERFEROMETRY VERSUS SCHEIMPFLUG TOMOGRAPHY IN INTRAOCULAR LENS POWER CALCULATIONS

Document Type : Preliminary preprint short reports of original research

Authors

Department of Ophthalmology, Faculty of Medicine, Alexandria University

Abstract

INTRODUCTION:
Automated keratometric (k) Readings provided by the partial coherence interferometry device (KIOLM) IOLMaster (version S.2, Carl Zeiss Meditec, Dublin, California, USA) have been the most widely used values for intraocular lens (IOL) power calculation and have long been considered the gold-standard keratometric measurements. The keratometer within the IOLMaster measures corneal power by analyzing reflections of light projected at 6 points on the cornea over a 2.3-mm paraxial radius.
Anterior segment imaging by the Pentacam Comprehensive Eye Scanner (Oculus, Inc., Wetzlar, Germany) isplaying more and more a vital role in preoperative evaluation of cataract patients. The Pentacam uses Scheimpflug technology to acquire detailed images of the cornea andof the anterior chamber. It uses a rotating camera that scans138,000 true elevation points over both the anterior andposterior corneal surfaces, forming a 3-dimensional imageof the cornea. These values are then analyzed by the incorporated software to obtain corneal pachymetry, topography, keratometry, and anterior chamber photography.

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