Enhanced Efficacy And Safety Of Oxygen-Enriched Rose Bengal And Green Light Corneal Cross-Linking

This study aims to assess the efficacy and safety of oxygen-enriched rose bengal and green light cross-linking (RGX) in comparison to the conventional method.

Prospective study at Fudan University.

The experimental subjects were divided into three cohorts: Group 1 (Control) underwent de-epithelialization and served as baseline; Group 2 (RGX-nO2) received standard RGX protocol involving de-epithelialization, staining with 0.1% rose bengal (Rb) for 20 minutes, exposure to green light (0.25 W/cm²) for 10 minutes in normoxia; Group 3 (RGX-hO2) received identical treatment as Group 2 with supplemental oxygen during irradiation. Central corneal thickness (CCT) was monitored, corneal biomechanical properties and resistance to enzymatic digestion were evaluated post-RGX. Corneal microstructure was analyzed via transmission electron microscopy, endothelial staining, and TUNEL assay.

Both RGX-hO₂ and RGX-nO₂ groups demonstrated a significant increase in corneal tensile strength by factors of 1.76 and 1.46, respectively. The mean times for complete corneal digestion were 23.2 ± 1.1 hours, 18.0 ± 2.0 hours, and 8.4 ± 0.9 hours for the RGX-hO₂, RGX-nO2, and Control groups, respectively. The average collagen fibril diameter (43.58 ± 0.93 nm vs. 40.46 ± 1.11 nm vs. 35.25 ± 0.75 nm) and the surface-to-surface spacing (11.67 ± 1.91 nm vs. 15.51 ± 1.66 nm vs. 24.93 ± 1.95 nm) showed statistically significant differences among the three groups. No detectable endothelial or stromal cell damage was observed through endothelial staining or the TUNEL assay.

Increasing the concentration of oxygen during the irradiation process enhances the RGX efficacy without causing obvious damage to rabbit’s endothelium or stromal cells.