Comparison of Two Non-diffractive Enhanced Monofocal Intraocular Lenses

In modern cataract surgery the aim of the procedure is not just the restoration of vision but to also achieve some spectacle independence. Bilateral implantation of monofocal intraocular lenses (IOL) aiming for emmetropia lead to high patient satisfaction levels in distance vision but leave patients dependent on spectacles in intermediate and near vision tasks.

To achieve high levels of spectacle independence the most commonly used option are multifocal intraocular lenses (MIOL). These MIOLs use either a refractive or diffractive optical design, a combination of both or segmented asymmetric optics. Usually, the characteristic diffractive ring patterns are incorporated on the posterior surface of an IOL, whereas the anterior lens surface remains purely refractive. However, a portion of patients experience problems with positive dysphotopsia symptoms such as halos and glare. Other potentially negative aspects of MIOLs are pupil size dependency and loss of light energy to higher order diffraction which can lead to reduced contrast sensitivity. In clinical studies diffractive lenses resulted in a better outcome in terms of optical quality, better contrast sensitivity and positive dysphotopsia phenomena than refractive multifocal lenses.

A newer concept of IOLs are non-diffractive enhanced range of vision (EROV) IOLs, sometimes also referred to as EDOF IOLs. The EROV IOLs with the least compromise concerning quality of vision are the group of so called enhanced monofocal IOL, also sometime referred to as monofocal plus IOL. These IOLs should result in better intermediate vison and provide contrast sensitivity and dysphotopsia results comparable to standard monofocal IOLs. These IOLs may be more adequate to meet the expectations of many presbyopic cataract patients, who were used to have a good distance vision and who were wearing spectacles when performing near vision tasks before surgery.

The aim of this study is to compare the clinical performance of a newer enhanced monofocal IOL (Evolux) with a standard enhanced monofocal IOL, the Tecnis Eyhance.