Abstract
Purpose :
The purpose of this work is to evaluate the effect of post-operative refractive outcomes on vision of patients implanted with presbyopia correcting intraocular lenses (IOLs) using computer simulations to predict the visual acuity (VA) at different distances in the presence of residual defocus and astigmatism.
Methods :
A set of 46 physiological eye models with realistic corneas and axial lengths, representative of a cataract population, were used to evaluate the VA provided by different IOLs [Weeber et al. 2010 JBO]: an aspheric monofocal, a monofocal that slightly extends depth of focus, a diffractive EDF, a new refractive EDF, a multifocal (MF) and a new full range of vision (ROV) lens. Computer simulations were performed for a 3mm physical pupil in white light using the radially averaged weighted optical transfer function to predict the monocular VA, which has shown high correlation (R2=0.97) with the clinical defocus curves [Alarcon et al IOVS 2023], for different levels of defocus and astigmatism. Astigmatism was induced in combination with defocus to compensate for the spherical equivalent.
Results :
Simulations showed that defocus and astigmatism reduced VA although the impact depended on the IOL design. In the presence of +\-0.5D defocus (sphere), monocular uncorrected distance VA was 0.1 logMAR or better for all eyes (100%) implanted with any of the two monofocal IOLs, as well as for the refractive and diffractive EDF IOLs. For the MF and ROV IOLs 0.1 logMAR was reached for 80% and 97% of eyes, respectively. Also, in the presence of 0.75D cylinder, all eyes implanted with the monofocal IOLs and the EDF IOLs achieved 0.1 logMAR or better. With the ROV IOL, 97% of the eyes achieved 0.1 logMAR, 10% more than with the MF.
Conclusions :
Computer simulations of visual acuity in eye models representing a cataract population show that the induction of defocus and astigmatism degrades VA. EDF IOLs provided high levels of VA in the presence of residual defocus and astigmatism, at the level of the monofocal IOLs. The new full range of vision IOL provided superior tolerance to defocus and astigmatism than the multifocal IOL.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.