Abstract
Abstract: :
Purpose: To evaluate the feasibility of a novel refraction based method of IOL calculation which may improve the accuracy of post–LASIK IOL calculations. The results of Phase I: AIRIC in normal patients is presented here. Methods: 20 normal patients undergoing routine phacoemulsification procedures were enrolled. Intraoperative autorefraction of the aphakic eye was performed after cataract removal, and the refractive vergence formula was used to derive the emmetropic IOL power. These results are compared to the pre–operative emmetropic IOL power calculations derived from the IOL Master. Results: Initial results show the mean difference in AIRIC derived emmetropic IOL power versus IOL Master derived emmetropic IOL power is –1.13D (range –2.5D to +0.5D). This would theoretically result in an average post–operative refraction of +0.8D (range +1.68D to –0.35D). Mean difference in intraoperative autokeratometry was +0.55D (range –0.96 to +0.75D). Conclusions: Aphakic Intraoperative Refraction for IOL Calculation (AIRIC) on average slightly underpowers the emmetropic IOL power as calculated by the IOL Master. Nonetheless, since this method of calculation is less dependent upon accurate keratometry, and weighted more heavily upon the accuracy of the refractive measurement, it may play a role in developing a more reliable method of IOL calculation for post–LASIK cataract patients in the future. Further refinements will likely improve the accuracy of this method.
Keywords: cataract • refractive surgery: other technologies • refraction