Analysis of the Effect of Pupil Size and Corneal Aberration on the Optical Performance of Premium Intraocular Lenses

Abstract

Background/Objectives: To assess the optical performance of two refractive premium IOLs across pupil sizes and values of corneal spherical aberration (SA). Methods: Two refractive IOLs were evaluated in this study: Tecnis Eyhance and Mini Well. The surface profiles were obtained to calculate the through-object MTF (TO MTF) curves and simulate optotype images. Entrance pupil sizes ranging from 2 to 5.5 and three corneal models were analyzed in the simulation: an average population aberrated cornea, an aberration-free cornea and a post-Lasik myopic cornea. Results: For Model 1 and pupil sizes between 3.0 and 3.5 mm, Mini Well provided acceptable visual quality from far to near distances, whereas Eyhance struggled to maintain visual quality at distances closer than intermediate. For patients with lower-than-normal corneal SA (i.e., more prolate corneas, such as post-hyperopic LASIK) both IOLs exhibited a hyperopic shift in far focus. Conversely, for patients with higher-than-normal corneal SA (i.e., more oblate corneas, such as post-myopic LASIK), the shift occurred in the myopic direction. Despite the implementation of an optimized IOL power to circumvent any shift, the TO MTF nevertheless reflected the interaction between corneal and IOL SA. Furthermore, the Mini Well demonstrated increased tolerance to less negative SA values, while Eyhance exhibited behavior consistent with a monofocal lens for more positive SA values. Conclusions: Surgeons should consider each patient's corneal asphericity and typical pupil diameter when selecting and calculating the power of the premium IOLs studied, particularly in patients with a history of refractive surgery.

Keywords: Lasik surgery; cataract; premium IOLs; refractive surgery.

Figure 1

Chart of optotypes and the corresponding simulated visual acuities. The printed “E” is not to scale.

Figure 2

Pupil size dependence of the Mini Well TO MTF curve considering Model 1. Simulated optotypes are shown for all pupil sizes and distances.

Figure 3

Dependency of the Mini Well TO MTF curves on the pupil size for Models 2 (a) and 3 (b). Simulated optotypes for far vision and all pupil sizes are shown.

Figure 4

Pupil size dependence of the Tecnis Eyhance TO MTF curve considering Model 1. Simulated optotypes are shown for all pupil sizes and distances.

Figure 5

Dependency of the Tecnis Eyhance TO MTF curves on the pupil size for Models 2 (a) and 3 (b). Simulated optotypes for far vision and all pupil sizes are shown.

Figure 6

Mini Well (a) and Tecnis Eyhance (b) TO MTF curves for the 3.5 mm pupil size and the three Models (black color for Model 1, red color for Model 2 and green color for Model 3). An optimized IOL power calculation was assumed to obtain the image of a far object on the retina. Simulated optotypes at far distance, 90 cm, 60 cm, and 40 cm are also shown.