Posterior capsule opacification (PCO) following phacoemulsification occurs due to proliferation of residual lens epithelial cells. Which IOL design feature has most significantly reduced PCO rates?

• A Hydrophilic acrylic material
• B Larger optic diameter (7 mm versus 6 mm)
• C UV-absorbing chromophore in the lens material
• D Square posterior optic edge with 360-degree sharp-edge barrier ✓

Explanation

A 360-degree square posterior optic edge creates a mechanical barrier that prevents migration of lens epithelial cells (LECs) from the equatorial bag across the posterior capsule. This 'bend' in the capsule at the IOL edge mechanically impedes LEC migration — the most evidence-based PCO-reducing design feature. Hydrophobic acrylic (Acrysof) has lower PCO than hydrophilic acrylic, but this is material rather than design. UV-absorbers protect against macular phototoxicity. Heparin surface modification reduces inflammatory cell adhesion but not PCO. YAG capsulotomy remains the treatment once PCO develops.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.