Extended Depth-of-Focus Intraocular Lens Based on Aberration-Neutral Technique.

PURPOSE: To design an extended depth-of-focus (EDoF) intraocular lens (IOL) with a full-aperture aberration-neutral profile and to evaluate its optical stability under decentration and tilt using an anatomically accurate schematic eye model.

METHODS

In this study, 'additional vision' refers to the functional intermediate/near vision range provided by the EDoF IOL beyond the distance focus. A new EDoF IOL based on the aberration-neutral technique was designed and optimised within the Navarro-Escudero model eye. Optical performance, including modulation transfer function through-object (MTF-TO), spot diagrams and ray tracing, was simulated under alignment, 0.5 mm decentration and 5° tilt using a numerical simulation method. Results were compared with a commercial monofocal IOL (IOL A) and two commercial EDoF IOLs (IOL B and IOL C) using the Liou-Brennan model eye.

RESULTS

Under perfect alignment, the new IOL achieved an MTF of 0.36 at 50 cycles/mm for distance and a continuous MTF-TO response from distance to near, confirming its EDoF functionality. Compared with IOL B and IOL C, the new design provided a wider depth of focus (1.2 D versus 1.1 D and 0.5 D) and a higher additional vision MTF (0.30 versus 0.19 and 0.27) under aligned conditions. Under 0.5 mm decentration, the distance MTF of the new IOL decreased by less than 3% (from 0.36 to 0.35), whereas IOL B and IOL C dropped to 0.09 and 0.23, respectively. Under 5° tilt, the additional vision MTF of the new IOL was 0.29, exceeding those of IOL B (0.20) and IOL C (0.19) by 45 and 53%, respectively. The MTF-TO curve showed no appreciable shift under tilt.

CONCLUSION

The proposed full-aperture, system-level aberration-neutral EDoF IOL maintains stable optical quality and preserves both distance and additional vision under decentration and tilt. Its systematic evaluation using an anatomically accurate schematic eye model provides a robust theoretical basis for clinical application in eyes at risk of postoperative IOL misalignments.