Abstract
Purpose: :
To evaluate and compare refractive outcomes of patients submitted to standard cataract surgery and intraocular lens (IOL) power calculation either by ultrasonic or optical biometry.
Methods: :
Prospective, observational, comparative case-series. Patients were randomly separated in two groups regarding IOL power calculating method. Ultrasonic and optical biometry were performed by the same examiner. One surgeon performed small incision phacoemulsification with standard chop technique, using the Acrysof IQ IOL model (Alcon Labs, Fort Worth, TX, USA) in all cases. The same examiner assessed final refraction 4 weeks after the procedure. Exclusion criteria was axial length < 19.5 mm or > 25.8 mm, and corneal astigmatism > 2.5 Diopters (D).
Results: :
Eighty-eight eyes of fifty-seven consecutive patients were included. Group 1 (ultrasonic biometry) consisted of 67 eyes of 44 patients, and Group 2 (optical biometry) 21 eyes of 13 patients. Group 1 desired final refraction was -0.75±0.265D (mean ± standard deviation), with achieved result of -0.49±0.509D. Group 2 desired final refraction was -0.40±0.51D, with achieved result of -0.09±0.61D. Difference between planed and observed final refraction outcome was 0.27±0.499D (-1.05 to 1.76D) in Group 1 and 0.28±0.39D (-0.65 to 0.90D) in Group 2. Five eyes (7.5%) in Group 1 showed a difference greater then 1.0D of planned and observed final refraction, while all eyes in Group 2 were within 1.0D of intended refraction.
Keywords: intraocular lens • cataract