Predicting the Optical Performance of Eyes Implanted with IOLs to Correct Spherical Aberration

Abstract

A "virtual surgery" approach was designed to predict the optical performance in pseudophakic eyes. In each subject, it was possible to obtain the eye's optical performance with a particular IOL and biometric data after surgery. Specifically, this modeling can be used to evaluate the tolerances to misalignments and depth of focus of IOLs correcting spherical aberration in actual eyes. This approach is quite powerful and is especially applicable to the study of current and future aberration-correction IOL designs.

Full 3-D OCT-based pseudophakic custom computer eye model

“…We found an average coefficient of correlation R = 0.93 between measured and simulated aberration. This compares with average coefficient of correlation R = 0.82 in Rosales and Marcos [14] and average coefficient of correlation R = 0.88 in Tabernero et al reports [15].…”

“…In contrast, in phakic eyes the crystalline lens exhibits a patient/age-dependent Gradient Index Distribution [37,38]. Computer eye models had been presented before [14,15], using biometric information gathered from multiple devices (anterior cornea from Placido disk topography; tilt and decentration from Purkinje imaging apparatus; anterior chamber depth from slit lamp; axial length from low coherence interferometer). We found an average coefficient of correlation R = 0.93 between measured and simulated aberration.…”

“…Several authors have presented the use of non-paraxial eye models for improved selection of the IOL to be implanted, in particular, for the calculation of IOL power with higher accuracy than regression-formulae [10][11][12][13]. Customized eye models have also been shown to accurately reproduce measured high order aberrations, when constructed using the anatomical parameters of individual patients [14,15]. These models are instrumental in understanding the relative contribution of the patient's corneal topography, IOL design, IOL tilt and decentration, and foveal misalignment, and as platforms to test what optical performance would have resulted if the eye had been implanted with a different IOL design.…”

“…These models are instrumental in understanding the relative contribution of the patient's corneal topography, IOL design, IOL tilt and decentration, and foveal misalignment, and as platforms to test what optical performance would have resulted if the eye had been implanted with a different IOL design. Typically, the anatomical parameters of the eye to build these eye models are obtained from various instruments (Placido Disk corneal elevation maps; Purkinje imaging IOL tilt, decentration and foveal position, IOL design provided by the manufacturer) [14,15]. Recently, quantitative OCT imaging has shown to be a powerful technology to obtain quantitative 3D optical biometry and geometry in individual eyes [16], providing, from a single instrument, all the ocular anterior segment information needed to build a custom pseudophakic model eye.…”

The Individual Virtual Eye: a Computer Model for Advanced Intraocular Lens Calculation

“…IOLs are the artificial lenses that are used in cataract surgery to replace the cloudy human crystalline lens. There is literature that evaluates IOL designs (mainly spherical versus aspheric) with RRT, without making use of corneal topography data, [17][18][19][20][21][22][23] while others explicitly use measured corneal topographies; [24][25][26][27][28][29] some studies additionally included polychromatic effects. 20,28 Franchini et al used real ray-tracing to study different lens-edge designs by analyzing the reflected glare images.…”