Abstract
Purpose :
Fibrosis is the main cause of failure in minimally invasive glaucoma surgery (MIGS), and Mitomycin-C and 5-Fluorouracil are too toxic for intraocular use. We hypothesise that adrenaline, a commonly used sympathomimetic, could have antifibrotic and vasoconstrictor effects in Schlemm' s canal and suprachoroidal MIGS.
Methods :
Human trabecular meshwork (TM) cells were treated with adrenaline (0%, 0.0005%, 0.01%) to assess their effects on contractility, cell viability, and the expression of key cell cycle and fibrosis genes. Adrenaline 0.05% was also intracamerally injected into five primary open-angle glaucoma patients undergoing iStent inject or MINIject surgery combined with phacoemulsification. All patients were evaluated for ocular and systemic adverse reactions, as well as preoperative and postoperative visual acuity, intraocular pressure, and anterior segment OCT results. One-way ANOVA was conducted for statistical analysis.
Results :
Adrenaline significantly reduced TM cell contractility in a dose-dependent manner, resulting in 8.2% (P < 0.001) and 91.0% (P < 0.0001) decrease in matrix contraction with adrenaline 0.0005% and 0.01%, respectively, compared to no drug control. Adrenaline did not exhibit any significant cytotoxicity even at high concentrations after 1-day treatment (P > 0.05). Adrenaline 0.01% significantly downregulated the expression of key cell cycle genes in the G2 and M phases, and decreased the expression of MRTFB and ACTA2 genes (P < 0.05). Intracameral injection of adrenaline 0.05% in the five MIGS patients did not cause any ocular or systemic adverse reactions or pupil changes (Fig 1).
Conclusions :
We recommend intracameral injections of adrenaline 0.05% as a cheap and safe drug to be used before MIGS insertion. Adrenaline decreases the risk of bleeding from the TM and also exhibits antifibrotic effects by arresting the cell cycle, thereby increasing the postoperative success rates in MIGS. Future aim will be to assess the long-term effects of adrenaline in clinical trials of new antifibrotic drugs.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.