Power Profile, Spherical Aberration And Expected Visual Acuity Of An Extended Depth Of Focus Intraocular Lens

To determine the power profile, spherical aberration (SA) and the expected visual acuity (VA) of the extended depth of focus (EDoF) intraocular lens (IOL) LuxSmart^TM (Bausch+Lomb) and compare them with those of a standard monofocal IOL with the same material and platform (LuxGood^TM, Bausch+Lomb).

Group of Applied Optics and Image Processing, Faculty of Optics and Optometry, Universitat Politècnica de Catalunya, Barcelona Tech, Spain.

Optometry and Vision Department, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Spain.

The power profile and SA of the EDoF LuxSmart^TM IOL were obtained and compared to those of a standard monofocal IOL, the LuxGood^TM model. Lenses with base power of 20 diopters (D) were measured using the NIMO TR1504 device (Lambda-X SA, Belgium) varying the optical zone of the lens from 2.0 to 5.0mm in steps of 0.5mm. In addition, the optical performance of both IOLs was evaluated through-focus (TF), between -3.0 and +1.0 D, using a model eye on optical bench. The assessment was performed with the area under the MTF (MTFa) across three pupil diameters (2.0, 3.0 and 4.5 mm at the IOL plane). The expected VA defocus curve for each IOL was derived from its TF-MTFa measurements.

The power profiles of the EDoF IOL and the reference monofocal have significant differences. Thus, while the monofocal IOL exhibits a mild power reduction (≈0.5D) towards the center of the lens, the EDoF IOL shows a noticeable increase of its refractive power (≈1.5D) from the periphery to the center. Moreover, in contrast to the aberration free profile of the monofocal design, the EDoF IOL shows either negative Z(4,0) SA for an optical zone between 2.0 and 3.0mm, or a combined negative Z(4,0) and positive Z(6,0) SA for optical zone larger than 3.0 mm. The optical performance of the EDoF IOL varies with pupil size. VA of -0.05 logMAR at 0.0D defocus (i.e. far vision) is predicted for the EDoF IOL with a depth of focus at logMAR 0.2 of 2.12D.

Unlike the monofocal LuxGood^TM IOL, the EDoF LuxSmart^TM IOL exhibits a significant gradient of power from the periphery (less power) towards the center of the lens (more power), with negative Z(4,0) and positive Z(6,0) SA for optical zones larger than 3.0mm. These findings suggest potential benefits for intermediate vision, although pupil dynamics has to be considered. The simulated VA for far vision with the EDoF IOL is comparable to that of the reference monofocal (-0.05 logMAR versus -0.1 logMAR respectively). Larger depth of focus reaching 2.12D at logMAR 0.2 is predicted for the EDoF lens.