Genipin Corneal Crosslinking Treatment in a Fusarium solani Keratitis Model
Marcela Huertas-Bello1, Luis David Sáenz1, Cristian N Rodríguez2, Myriam L Navarrete2, Marcel Y Avila1, Elena Koudouna1,3
1Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota, Colombia, South America, 2Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogota, Colombia, South America, 3Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom
Purpose: Fungal keratitis is a corneal infection caused by pathologic fungi, mostly Fusarium and Aspergillus species. It is a severe sight threatening disease due to late diagnosis and poor therapeutic outcomes often leading to the formation of ulcers, perforation and permanent blindness. In addition, there is no good broad-spectrum antifungal medication and no new treatments have been recently approved. Furthermore, even with early treatment, many patients remain visually impaired and require surgical interventions. Genipin is a natural crosslinking agent with low toxicity. We previously showed that genipin exerts antibacterial properties in an ex vivo model of infectious keratitis and that it can retard collagenolysis and delay tissue enzymatic digestion. The purpose of this study was to evaluate the effects of genipin corneal crosslinking in an ex vivo model of Fusarium solani keratitis.
Methods: Excised pig corneoscleral buttons maintained in organ culture. Corneas were intrastromally injected with a 105 Fusarium solani suspension (ATCC NCPF 2699) using a McFarland standard. Eyes were kept in pairs and after 4 hours, one eye was treated with saline solution + HCO3 (vehicle) and the contralateral eye was treated with genipin (n=6 pairs). Corneas not exposed to fungi were used as sterility control. After 48 h of incubation, corneas were homogenized, and the resulting suspension was serially diluted and plated to determine the viable colony-forming units (CFU)/cornea. Additionally, corneas were processed for histological examination.
Results: Genipin corneal crosslinking treatment was effective in inhibiting Fusarium solani compared to vehicle-treated controls demonstrated by histology. Fungi burden of the genipin-treated corneas was diminished and a decrease in the CFU/cornea was observed. Sterility control corneas maintained uninfected.
Conclusions: Corneal genipin crosslinking is a potential complementary therapy for Fusarium solani keratitis. Its plausible clinical application for the management and treatment of fungal keratitis deserves further examination.
Disclosure: S (Koudouna)
Support: European Commission Horizon 2020 Grant 793328 – Marie Curie Individual Global Fellowship (Koudouna)