Refining Micro-Monovision Through Monofocal Plus Intraocular Lenses

Micro-monovision aims to expand the depth of focus (DoF) while maintaining uncompromised binocular distance vision. Although standard monovision has been an established procedure, it has recently enjoyed renewed interest due to the introduction of RayOne EMV (Rayner), an IOL purposely designed to work in such a configuration. In this study, we evaluated whether employing alternative monofocal-plus approaches could offer similar advantages in micro-monovision. 

David J. Apple Center for Vision Research, Department of Ophthalmology, University of Heidelberg, Germany.

In addition to RayOne EMV, Acunex Quantum (Teleon) was used as an alternative approach. Samples with diopter powers of +10, +20, and +30D were included for evaluation. The investigation was conducted on an optical bench featuring a physiological-eye model and polychromatic light. Micro-monovision was simulated by adding the following myopic offset: -0.25D, -0.5D, -0.75D, and -1D, which was combined with a plano target. Simulated visual acuity (simVA) was assessed across various distances, spanning from infinity to 40 cm. Binocular summation was accounted for in recorded images corresponding to each studied condition.

Acunex Quantum produced more extended DoF than RayOne EMV for all IOL powers and offsets, with the latter preserving better VA for higher myopic targets. With a -0.25D offset, both models maintained good simVA, slightly improving DoF. For -0.50D, Acunex Quantum (10D) showed lower monocular VA; however, 20D and 30D IOLs demonstrated 0.00 logMAR and marked DoF improvement. The -0.75D offset reduced monocular vision with 10D, but this effect was less noticeable for higher IOL powers. Over one-VA-line improvement was noted at 50cm for two lenses. Intermediate vision improved with the -1D offset, nearing two lines. Conversely, distance VA was substantially reduced in the 10D groups, but increased IOL powers mitigated this difference.

This study indicates the suitability of monofocal-plus technology for micro-monovision, particularly in patients with a higher power of the implanted IOL. Acunex Quantum appears to extend the intermediate range more compared to RayOne EMV. The observed improvement varied, however, across IOL powers, suggesting potential contributions from spherical aberration.