ESCRS - POCOR172 - Frequent Reapplication Of Hpmc-Based Riboflavin Solution Impairs Corneal Stiffening During Uv-Light Irradiation In Cxl Procedures

Frequent Reapplication Of Hpmc-Based Riboflavin Solution Impairs Corneal Stiffening During Uv-Light Irradiation In Cxl Procedures

Published 2026 - 44th Congress of the ESCRS

Reference: POCOR172 | Type: Free paper | DOI: 10.82333/6g0j-jz56

Authors: Dr Robert Herber 1 , David Tetz 2 , Dr Max Franke 3 , Dr Isaak Fischinger 4 , Prof. Dr Frederik Raiskup* 1 , Dr Tammo Ripken 3 , Prof. Dr Ramin Khoramnia 1 , Dr Theo G. Seiler 5

1Department of Ophthalmology,Faculty of Medicine and University Hospital Carl Gustav Carus,Dresden,Germany, 2Augentagesklinik Spreebogen,Berlin,Germany, 3Laser Zentrum Hannover e.V, ,Hannover,Germany, 4Augentagesklinik Spreebogen,Dresden,Germany, 5Institute for Refractive and Ophthalmic Surgery ,Zurich,Switzerland;Department of Ophthalmology,Medical Faculty and University Hospital ,Düsseldorf,Germany;Department of Ophthalmology,Inselspital Bern, University of Bern,Bern,Switzerland

Purpose

To investigate the influence of different application frequencies of HPMC-based riboflavin (RF) during UV irradiation on corneal biomechanical stiffening and riboflavin concentrations after inhibition in porcine eyes.

Setting

Experimental laboratory study

Methods

150 freshly enucleated porcine eyes underwent accelerated cross-linking using a 9×10 protocol, with standardized RF inhibition prior to UV irradiation. Eyes were divided into five groups based on drop application during UV exposure: (1) RF every 1 minute, (2) RF once after 5 minutes, (3) Balanced salt solution (BSS) after 5 minutes, (4) BSS-soaked sponge post-inhibition, followed by BSS after 5 minutes, (5) Control group. Primary outcome was Young’s modulus measured by corneal strip extensometry. Secondary outcomes included UV transmission during irradiation. RF concentrations post-inhibition were assessed via two-photon microscopy under three conditions: BSS rinsing, swabbing with a BSS-soaked sponge, and a RF-soaked sponge.

Results

At 10% strain, Groups 2 and 3 showed significantly higher Young’s modulus than the control (p<0.05), while Groups 1 and 4 did not differ significantly. UV transmission was lowest in Group 1 and highest in the others. RF concentration decreased after BSS rinsing but remained stable with RF-soaked sponge application.

Conclusions

RF application during UV exposure influences corneal stiffening due to a shielding effect, with lower UV availability correlating with reduced biomechanical enhancement. Additionally, corneal preparation post-inhibition plays a critical role in optimizing treatment efficacy.