Presbyopia correcting intraocular lens (PC-IOL) technology has been available for decades. Lens designs have included refractive (e.g. AMO ReZoom), apodized diffractive (e.g. Alcon Acrysof ReSTOR/PanOptix), accommodating (B\&L Crystalens), and extended depth-of-focus (e.g. J\&J Symfony) technology. Spectacle independence is significantly higher with PC-IOLs when compared with that of monofocal IOLs.1,2 Despite their clear benefits, PC-IOLs are not without drawbacks. Any IOL that splits light to deliver distinct distance and near foci creates the potential for photic phenomenon, which patients may perceive as glare, haloes, and starbursts.3,4
Pseudoaccommodation is defined as an increased depth-of-focus in an emmetropic eye that does not have the ability to change its refractive power. Spherical aberration, which may come from the cornea or IOL, plays an important role in pseudoaccommodation.5,6 There is a small body of literature that IOLs (e.g. Mini WELL, SIFI, Catalina, Italy) with highly-positive spherical aberration can result in significant pseudoaccommodation and lower unwanted optical phenomena than current multifocal IOLs.7
The Alcon Vivity PC-IOL is a hydrophobic acrylic, non-diffractive, extended depth of focus IOL designed for implantation in the capsular bag following cataract extraction. The single-piece IOL has a 6.0 mm diameter and has a hyper-prolate profile that extends the depth of focus to deliver a broader range of sharp vision, with the glare and halo profile approaching that of a monofocal IOL.8
The Bausch \& Lomb enVista MX60E is a posterior chamber hydrophobic acrylic IOL. The single-piece IOL has a 6.0 mm diameter and has a neural aspheric optical profile. This neutral aspheric profile, combined with the cornea's natural positive spherical aberration, may extend the depth of focus relative to other negative aspheric hydrophobic acrylic monofocal IOLs on the market.
To date, there is no existing literature comparing the visual performance and patient reported outcomes of the two above mentioned lens technologies; namely, one that relies on a non-diffractive, hyper-prolate profile and another that relies on the cornea's natural positive spherical aberration to provide pseudoaccommodation.
The FDA Summary of Safety and Effectiveness on the Alcon Vivity IOL compares visual and patient reported outcomes of the Alcon Vivity IOL and the Alcon Acrysof SN60WF. While the Alcon Acrysof SN60WF and Bausch \& Lomb enVista lenses are not identical, they are considered similar. The document reported improved intermediate vision with the Alcon Vivity over the SN60WF, and rates of reported visual disturbances were similar between the two devices.
Whereas the Alcon Acrysof SN60WF has a negative aspheric optical profile, the Bausch \& Lomb enVista has a neutral aspheric optical profile. Theoretically, the Bausch \& Lomb enVista IOL may provide increased intermediate vision compared with the SN60WF.
