Work

Evaluation of Verteporfin as a Novel Antifibrotic Agent in a Rabbit Model of Glaucoma Filtration Surgery

Year: 2023

Type: article

Abstract: Purpose Verteporfin is a benzoporphyrin derivative which is FDA-approved for treatment of choroidal neovascularization in conjunction with photodynamic therapy. It has been shown to prevent fibrosis and scar formation in several organs and represents a promising novel antifibrotic agent for glaucoma surgery. The goal of this study is to determine the effect of verteporfin on wound healing after glaucoma filtration surgery. Design Preclinical study using a rabbit model of glaucoma filtration surgery. Subjects Eight New Zealand white rabbits underwent glaucoma filtration surgery in both eyes. Methods Eyes were randomized into four study groups to receive a postoperative subconjunctival injection of 1 mg/mL verteporfin (n=4), 0.4 mg/mL mitomycin C (MMC) (n=4), 0.4 mg/mL MMC + 1 mg/mL verteporfin (n=4), or balanced salt solution (BSS) control (n=4). Bleb survival, vascularity, and morphology were graded using a standard scale over a 30-day period, and intraocular pressure (IOP) was monitored. At 30 days post-operative or surgical failure, histology was performed to evaluate for inflammation, local toxicity, and scarring. Main Outcome Measures The primary outcome measure was bleb survival. Secondary outcome measures were IOP, bleb morphology, and bleb histology. Results Compared to BSS control blebs, verteporfin-treated blebs demonstrated a trend towards increased surgical survival (mean 9.8 vs 7.3 days, log rank p=0.08). MMC-treated blebs survived significantly longer than verteporfin-treated blebs (log rank p=0.009), with all but one MMC-treated bleb still surviving at post-operative day 30. There were no significant differences in survival between blebs treated with combination verteporfin + MMC and MMC alone. MMC-treated blebs were less vascular than verteporfin-treated blebs (mean vascularity score 0.3 ±0.5 for MMC vs 1.0 ± 0.0 for verteporfin, p<0.01). Bleb histology did not reveal any significant toxicity in verteporfin-treated eyes. There were no significant differences in inflammation or scarring across groups. Conclusions Although verteporfin remained inferior to MMC with regards to surgical survival, there was a trend towards increased survival compared to BSS control and it had an excellent safety profile. Further studies with variations in verteporfin dosage and/or application frequency are needed to assess whether this may be a useful adjunct to glaucoma surgery.

Source: Ophthalmology Science

DOI: 10.1016/j.xops.2023.100448