Photochemical Crosslinking as an Adjunct for Repairing Corneal Perforations in Rabbits

To assess the efficacy and tolerability of Rose Bengal-induced photochemical crosslinking (RB-PCL) as an adjunct to suturing for corneal perforation repair in rabbits.

A 4.5 mm corneal wound was created in New Zealand White Rabbits (right eyes), followed by suturing and RB-PCL treatment using 532 nm green light (0.6 W/cm²) and 0.01% RB photosensitizer. A control group received sutures alone. Healing was evaluated at Weeks 1, 2, and 4 using slit-lamp biomicroscopy, anterior segment optical coherence tomography (AS-OCT), RT-PCR for α-SMA gene expression, and immunofluorescence for myofibroblast activation. Histopathological changes were assessed via Hematoxylin and Eosin (H&E) staining, and corneal endothelial cell counts were taken to assess cytotoxicity.

RB-PCL accelerated suture removal by Day 5, while sutures in the control group required longer retention. At Weeks 1 and 2, RB-PCL demonstrated lower inflammation and reduced corneal opacity. By Weeks 2 and 4, α-SMA expression was significantly reduced in the RB-PCL group, indicating reduced myofibroblast activation and fibrosis. H&E staining showed complete healing in the RB-PCL group by Week 2, whereas the control group had incomplete repair. By Week 4, the RB-PCL group had better fiber arrangement, while the control group showed persistent fibrosis. Immunofluorescence confirmed reduced α-SMA expression in the RB-PCL group. No retinal damage was observed, and endothelial cell counts were similar between groups, indicating RB-PCL's tolerability.

RB-PCL improved corneal wound healing, reduced fibrosis and opacity, and allowed earlier suture removal without phototoxicity. These results suggest RB-PCL is a promising adjunct for corneal perforation repair, enhancing both efficacy and tolerability.