Binocular intermediate vision enhancement without compromising optical quality using a SwissPhob enhanced monofocal intraocular lens.

Purpose

To evaluate binocular intermediate visual acuity and objective optical quality following implantation of a novel advanced monofocal intraocular lens (IOL) (SwissPhob), designed to enhance intermediate vision without compromising contrast sensitivity or overall visual quality.

Methods

This prospective, noncomparative study included 60 eyes of 30 patients undergoing bilateral cataract surgery with the SwissPhob enhanced monofocal IOL within 2 weeks. Pre- and postoperative assessments included uncorrected and best-corrected distance and near visual acuity (logMAR), binocular uncorrected intermediate visual acuity at 66 cm, and objective optical quality metrics derived from ray-tracing aberrometry (iTrace). Spherical aberration, higher-order aberrations (HOAs), modulation transfer function (MTF), and visual Strehl ratio based on the optical transfer function (VSOTF) were analyzed.

Results

Postoperatively, all eyes achieved an excellent binocular intermediate visual acuity of 0.14 logMAR (20/25). The mean postoperative uncorrected distance visual acuity was 0.04 ± 0.08 logMAR (median = 0.00 logMAR; 20/20; IQR 0.00-0.00 logMAR). The median spherical aberration decreased to 0.00 μm (IQR -0.03 to 0.07), and HOA reduced to 0.18 μm (IQR 0.12-0.48). Postoperative optical quality was favorable, with a mean MTF of 0.31 ± 0.11 and a VSOTF of 0.28 ± 0.15. On multivariable analysis, higher preoperative MTF independently predicted higher postoperative MTF (odds ratio 3.52, 95% CI 1.15-14.0).

Conclusion

The SwissPhob enhanced monofocal IOL provides consistent improvement in binocular intermediate vision while preserving excellent distance vision and favorable optical quality. Intermediate vision appears to be mediated by controlled residual HOAs without reliance on spherical aberration, resulting in preserved contrast transfer and visual quality.