Monofocal intraocular lens based on the Bessel principle for improved intermediate vision: a comparative assessment

Background: To compare the optical qualities of a novel enhanced monofocal intraocular lens (IOL), against a well-established IOL through in vitro benchmarking. Methods: Optical benchmarking was conducted using the OptiSpheric IOL PRO2 device in compliance with International Organization for Standardization (ISO) guidelines. Optical quality was assessed using the modulation transfer function (MTF), point spread function (PSF), area under the MTF (MTFa), and 1951 USAF test charts. Measurements were taken at 3.0 mm and 4.5 mm apertures using a model cornea that induced 0.13 µm of spherical aberration to simulate clinical performance. Results: Both IOLs demonstrated comparable optical performance. At a 3 mm aperture, the Extend IOLs produced an average MTF at 50 lp/mm of 0.38 ± 0.01, while the ICB00 produced 0.36 ± 0.01. The MTFa and derived logMAR visual acuity (VA) curves showed nearly complete overlap for defocus levels less than -1.25 D, with both lenses yielding identical VA at far focus (-0.09 logMAR). At higher defocus levels, the observed difference between the models accounted for <0.02 logMAR, which is negligible for standard VA testing. Point spread function assessments revealed comparable light distribution for both IOLs. Conclusion: Under laboratory conditions, the Hanita Extend IOL shows comparable results to the Tecnis Eyhance ICB00 regarding MTF function, USAF-Chart images, and PSF assessment.