Indian Journal of Ophthalmology (Jan 2015)

Positional accommodative intraocular lens power error induced by the estimation of the corneal power and the effective lens position

  • David P Piñero,
  • Vicente J Camps,
  • María L Ramón,
  • Verónica Mateo,
  • Rafael J Pérez-Cambrodí

DOI
https://doi.org/10.4103/0301-4738.159882
Journal volume & issue
Vol. 63, no. 5
pp. 438 – 444

Abstract

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Purpose: To evaluate the predictability of the refractive correction achieved with a positional accommodating intraocular lenses (IOL) and to develop a potential optimization of it by minimizing the error associated with the keratometric estimation of the corneal power and by developing a predictive formula for the effective lens position (ELP). Materials and Methods: Clinical data from 25 eyes of 14 patients (age range, 52-77 years) and undergoing cataract surgery with implantation of the accommodating IOL Crystalens HD (Bausch and Lomb) were retrospectively reviewed. In all cases, the calculation of an adjusted IOL power (P IOLadj ) based on Gaussian optics considering the residual refractive error was done using a variable keratometric index value (n kadj ) for corneal power estimation with and without using an estimation algorithm for ELP obtained by multiple regression analysis (ELP adj ). P IOLadj was compared to the real IOL power implanted (P IOLReal , calculated with the SRK-T formula) and also to the values estimated by the Haigis, HofferQ, and Holladay I formulas. Results: No statistically significant differences were found between P IOLReal and P IOLadj when ELP adj was used (P = 0.10), with a range of agreement between calculations of 1.23 D. In contrast, P IOLReal was significantly higher when compared to P IOLadj without using ELP adj and also compared to the values estimated by the other formulas. Conclusions: Predictable refractive outcomes can be obtained with the accommodating IOL Crystalens HD using a variable keratometric index for corneal power estimation and by estimating ELP with an algorithm dependent on anatomical factors and age.

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