Enhancing the Intermediate Vision of Monofocal Intraocular Lenses Using a Higher Order Aspheric Optic.

Aixa Alarcon,Henk Weeber,Patricia A Piers,Gerd U Auffarth,Bram Koopman,Carmen Cánovas

doi:10.3928/1081597x-20200612-01

Abstract

To describe and evaluate a new monofocal intraocular lens (IOL) designed to improve intermediate vision using a unique refractive technology. The new monofocal lens is based on a higher order aspheric optic and is designed to improve intermediate vision. Simulated visual acuity from far to -2.00 diopters (D) was calculated using optical bench data. The effect of corneal higher order aberrations (HOAs) on simulated visual acuity, pupil size, and decentration was assessed using realistic computer eye models. The susceptibility to photic phenomena was evaluated by measuring preclinically the intensity of the light distribution in the retinal plane. The new lens design was compared to a standard aspheric monofocal IOL that shares the same platform, material, and primary spherical aberration as the new design. Simulated defocus curves showed increased simulated visual acuity in the intermediate range compared to a standard aspheric monofocal IOL with comparable distance vision, independently of the pupil size and corneal HOAs. At -1.50 D, the new IOL design provided a gain of approximately 0.1 logMAR, whereas at distance, the difference was less than 0.05 logMAR. The tolerance to decentration was also similar in both designs. Finally, experimental results indicate that the susceptibility to photic phenomena with the new lens design was similar to that of a standard aspheric monofocal IOL. Preclinical data showed that the new lens design improves intermediate vision while maintaining comparable distance image quality and keeping the same photic phenomena profile as a standard aspheric monofocal IOL. [J Refract Surg. 2020;36(8):520-527.].

Highlights

Simulated defocus curves showed increased simulated visual acuity in the intermediate range compared to a standard aspheric monofocal intraocular lens (IOL) with comparable distance vision, independently of the pupil size and corneal higher order aberrations (HOAs)
Preclinical data showed that the new lens design improves intermediate vision while maintaining comparable distance image quality and keeping the same photic phenomena profile as a standard aspheric monofocal IOL
Before the introduction of the aspheric technology, the standard of care was the use of monofocal spherical intraocular lenses (IOLs) that have spherical optical surfaces that are well known to induce primary spherical aberration

Summary

Methods

The new monofocal lens is based on a higher order aspheric optic and is designed to improve intermediate vision. The new lens design was compared to a standard aspheric monofocal IOL that shares the same platform, material, and primary spherical aberration as the new design. Primary spherical aberration has a distinct pattern for how it influences power, increasing or decreasing as a power of r2, where r is the radius of the pupil. Figure A reveals that the increases in central power designed for this lens are more localized and do not increase in the same way as would be expected by primary spherical aberration. Because of the absence of zones, discontinuities, and diffractive structures, the proposed design is expected to keep straylight and photic phenomena at the same level as a standard aspheric monofocal IOL

Results

Discussion

Conclusion