Balanced Extended Vision Procedure: Preclinical Analysis of a Non-diffractive Approach to Full Range of Vision After Cataract Surgery.

Abstract

Purpose: To assess the optical bench performance of a novel non-diffractive, wavefront-shaping intraocular lens (IOL) optimized for near vision (PF), and to evaluate its complementary use with its companion extended depth of focus (EDOF) model in the Balanced Extended Vision Procedure (BEVPx; AST VisionCare, Inc).

Methods: A preclinical comparative study was conducted using the PMTF device (Lambda-X Ophthalmics) to measure modulation transfer function (MTF) through-focus at 50 lp/mm in accordance with International Organization for Standardization (ISO) standard 11979-2:2014. Visual performance was further assessed by United States Air Force target imaging at multiple pupil sizes. Defocus curves were computed from MTF data to predict functional visual acuity. Optical performance was evaluated for PF and EDOF lenses (AST VisionCare, Inc) both individually and in combination, to simulate binocular outcomes in the BEVPx approach.

Results: Both IOLs demonstrated equivalent distance vision performance. The EDOF lens provided superior intermediate optical quality, whereas the PF lens enhanced near-visual performance beyond +2.50 diopters without loss of distance acuity. Simulated defocus curves revealed a dual-peak profile for the PF lens, maintaining predicted visual acuity better than 0.2 logarithm of the minimum angle of resolution across distance-to-near vergences. Combining the two lenses yielded a continuous defocus curve with functional vision across the entire range, supporting the rationale of the BEVPx strategy.

Conclusions: The PF IOL introduces a non-diffractive solution for extending vision into the near range, and may provide a full range of high-quality vision with reduced risk of photic phenomena, both alone and in combination with the EDOF lens. Preclinical evidence supports the BEVPx approach as a promising strategy to bridge the gap between EDOF and trifocal IOL designs.