Multifocal Lens Implantation Research Articles

Asymmetric multizone lenses--a new concept in multifocal intraocular lenses

Asymmetrical multifocal lenses (MIOLs) represent a new concept for binocular implantation of MIOLs: one asymmetrical IOL--destined for implantation in the dominant eye--is favouring distance vision by assuring that 60-70% of the light rays coming from an object will pass through the distance part of the optic. The other IOL--destined for implantation in the second eye--is favouring near vision, enabling that 60-70% of the light energy will be focused by the near zone(s) of the IOL. Modulation transfer function (MTF), Strehl-Ratio (SR) and resolution efficiency (RE) were determined in both foci by in vitro measurement. Defocus curves were performed after clinical implantation as well as after "optical implantation" by means of an optical device developed by Reiner. In vitro measurements showed superior results of SR and RE in the favoured focus of the MIOL. Defocus curves after clinical and "optical" implantation yielded higher peaks for visual acuity and contrast in the favoured focus. First theoretical and clinical results do confirm the new concept of asymmetrical multifocal IOLs.