Healing modulation in glaucoma surgery after application of subconjunctival triamcinolone acetate alone or combined with mitomycin C: an experimetal study

ABSTRACT Objective: to study the efficacy and safety of the use of subconjunctival triamcinolone acetate alone or in combination with mitomycin C as a modulator of trabeculectomy healing in rabbits. Methods: we submitted thirty male, albino, New Zealand rabbits to bilateral trabeculectomy. We divided the animals into four experimental groups with 15 eyes per group: control, mitomycin C, triamcinolone acetate and triamcinolone acetate + mitomycin C. We performed aplanation tonometry and clinical analysis of the bleb through the Moorfields Graduation System in the postoperative period. For the evaluation of healing, we carried out the quantitative analysis of the inflammatory infiltrate (polymorphonuclear) through Hematoxylin & Eosin staining, and vascular proliferation, through immunohistochemistry. Results: we observed a significant decrease in postoperative intraocular pressure in all groups compared with the preoperative pressure (p<0.001). However, there was no difference between groups (p=0.186). The triamcinolone + mitomycin C acetate group presented better indices as for the maximum bleb height and vascularization of the bleb central area (p=0.001); in addition, there was a lower inflammatory response (p=0.001) and lower vascular proliferation (p=0.001) in the intermediate phase of the study compared with the monotherapies. Conclusion: the combination of mitomycin C and triamcinolone acetate resulted in a synergistic action between these agents, with broader and more diffuse blebs, less inflammatory infiltrate and less vascular proliferation in the intermediate stages of follow-up in this animal model.