# The Effect of the Capsular Bag on the Optical Performance of an IOL Measured in an Ex Vivo Model

## TL;DR

This study evaluates how the capsular bag affects the optical performance of intraocular lenses using an ex vivo model.

## Contribution

A novel ex vivo model was developed to assess IOL optical performance under realistic biomechanical conditions.

## Key findings

- Baseline straylight from phakic capsular bags was comparable to young healthy eyes.
- Diffractive EDoF and trifocal IOLs showed higher susceptibility to capsular irregularities.
- The model captures biologically relevant inter-specimen variability in optical performance.

## Abstract

The purpose of this study was to investigate the effect of the capsular bag on the optical performance of different intraocular lens (IOL) designs, and to develop and validate an ex vivo human capsular bag model that enables quantitative optical evaluation under anatomically relevant biomechanical conditions.

Human cadaver eyes (n = 8) were prepared using a modified Choi-Apple technique to isolate the intact uveolenticular complex, which was stabilized with custom-designed 3D-printed rings. Following lens extraction, five commercially available IOLs (1 monofocal-plus, 2 Extended Depth of Focus [EDoF], and 2 trifocal designs) were sequentially implanted. Optical performance was evaluated with the OptiSpheric IOL PRO2 and a modified C-Quant setup. Metrics included modulation transfer function (MTF), simulated visual acuity (SimVA), point spread function (PSF), and forward light scattering (FLS).

The model enabled optical assessment of IOLs within the biomechanical environment of the capsular bag while capturing biologically relevant inter-specimen variability. Baseline straylight from phakic capsular bags averaged 0.75 ± 0.21 log(s), comparable to values in young healthy eyes. Defocus curves and United States Air Force (USAF) resolution images revealed IOL-specific variations consistent with reported clinical outcomes. Diffractive EDoF and trifocal IOLs exhibited higher susceptibility to capsular irregularities and more pronounced photic phenomena compared with monofocal-plus and refractive EDoF designs.

This study provides a platform for quantitative evaluation of the optical quality of IOLs within explanted human capsular bags, using the surrogate parameter SimVA. This approach enables assessment of lens optical performance within its designated anatomic setting, offering valuable predictive insights into optical quality and visual outcomes before initiating clinical trials.