Abstract
Purpose: :
to evaluate the feasibility of refractive prediction by Partial Optical Coherence Interferometry in patients submitted to standard cataract surgery.
Methods: :
Prospective, observational, case-series. 100 eyes of 65 patients ( mean age 72 years) affected by age-related cataract were examined. In each patient the measurements of axial length(AL), corneal parameters and expected refraction for each IOL type and power were performed with the IOL Master (Zeiss, Jena, Germany). 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. Patients with intraoperative complications were excluded from the study. 4 weeks after surgery BSCVA and refractive data were obtained for the mean spherical equivalent calculation, which has been compared with the predicted refraction.
Results: :
The mean numerical error and the mean absolute error (MAE) in predicted refraction were - 0.15 D ± 0.55 DS and 0.44 D ± 0.36 DS , respectively. The percentage of previsions with a MAE of less than 0.5 D was 68 % , between 0.51 and 0.9 D was 24 %, between 1 and 1.5 D was 6 %, between 1.51 and 1.9D was 2 %.In the eyes with AL < 22 mm (Group1, N=9) the MAE was 0,37 D ± 0.27 DS; in those with AL between 22-26 mm (Group 2, N=74) the MAE was 0.44D ± 0.39 DS and in the eyes with AL > 26mm (Group 3, N= 17) the MAE was 0,51 D ± 0,31 DS.
Conclusions: :
Optical biometry showed good accuracy in determining IOL power calculation in the present study. 92 % of eyes were within 1.0D of intended refraction. No statistically significative differences were recorded between eyes with different axial length.
Keywords: intraocular lens • cataract • refraction