Abstract
Purpose :
Optical performance of extended depth of focus (EDoF) intraocular lenses (IOLs) is commonly evaluated by measuring Zernike spherical aberrations (SA) with a commercially available aberrometer. The goal of the study is to assess errors induced by the wavefront estimated by a limited number of SAs.
Methods :
An ultrahigh resolution Shack-Hartmann wavefront sensor was developed by using a small lenslet array (133 µm) and a large CCD sensor (24 by 36 mm). The pupil was magnified by a factor of 5, resulting in 26.6 µm sampling resolution. Four refractive EDoF IOLs with 20D (Vivity, Alcon Laboratories, Inc; Tecnis Eyhance, Johnson & Johnson Vision; Isopure, PhysIOL; and Lucidis, Swiss Advanced Vision) in a wet chamber filled with the balanced salt solution were measured with zonal and Zernike-based modal wavefront reconstruction methods. The modal method calculated Zernike coefficients up to the 18th order while the zonal method reconstructed the local wavefront for each lenslet. The reconstructed wavefronts were analyzed for 2, 3, and 4 mm diameters.
Results :
All IOLs had negative 4th-order SA for 4 mm diameter, and Isopure and Lucidis had the largest (-0.34 µm) and smallest (-0.07 µm) magnitude, respectively. The magnitude was reduced significantly for the smaller diameters except that Lucidis had a slight increase (-0.12 µm). All IOLs had 6th- and 8th-order SAs, and Vivity and Lucidis also showed the 10th-order SA. The wavefront difference between the zonal (up to the 6th order) and modal methods represented by the mean squared error (MSE) was larger in Vivity and Lucidis, compared to Eyhance and Isopure. However, further increasing the Zernike fit up to the 10th order reduced the MSE significantly for Vivity and Lucidis while the negligibly small MSE for Eyhance and Isopure remained unchanged. With even up to the 18th-order polynomials for Vivity and Lucidis, the MSE remained significant.
Conclusions :
The study suggested that the recent refractive EDoF IOLs have a complicated optical profile that cannot be characterized sufficiently by a relatively small number of Zernike SAs. Therefore, using a commercial aberrometer to investigate the optics of the specialty IOLs could misinterpret the true design performance.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.