Investigation of the effects of corneal collagen cross-linking treatment on an experimental bacterial keratitis model and comparison of topical antibiotic treatment with the combined treatment

This study was conducted to investigate the effects of an experimental bacterial keratitis model on the corneal collagen cross-linking treatment (CXL), and also to compare topical antibiotic treatment with the combined treatment. The study involved 40 young adult female Sprague Dawley rats, which had a 2 mm scraped defect of the central corneal epithelium in both eyes. The rats were divided into two equal groups. The first group was inoculated into both eyes with standard Pseudomonas Aeruginosa (PA) from a strain suspension prepared from 0.05 ml (Group 1), and the second group was inoculated with standard Methicillin Resistance Staphylococcus Aureus (MRSA) strains from a suspension prepared from 0.05 ml (Group 2). Group 1 was divided into four sub-groups: Group 1A were treated by collagen cross-linking (CXL), group 1C were treated with topical tobramycin drops CXL+CXL, group 1D were treated with topical tobramycin drops, and group 1B were left untreated in order to create a control group. Similarly, group 2 was also divided into four sub-groups: Group 2A were treated by CXL, group 2C were treated with topical 5% fortified vancomycin drops CXL + CXL, group 2D were treated with topical 5% fortified vancomycin drops, and group 2B were left untreated in order to create a control group. The CXL was performed on the third day following the inoculation and topical drop therapy. Following the inoculation of microorganisms on the third and seventh day, biomicroscopy and microbiologic assessments were performed. In the treatment, which compared baseline in all groups before treatment, the size of keratitis infiltrations, recession of corneal edema, corneal swab samples were obtained from the reduction in reproduction. The results were statistically significant (p <0.01). Keratitis infiltrations groups were conducted on the seventh day for 1C and 1D according to 1B, whilst groups 2A, 2C and 2D were conducted according to 2B, which showed a significant statistical reduction (p <0.01). On the seventh day, focal groups were conducted in corneal edema group 1D according to 1B and in group 2A, 2C and 2D according to 2B, which revealed a significant statistical reduction (p <0.01). On the seventh day, reproduction in culture was obtained from corneal swab samples in groups 1C and 1D according to 1B, in groups 1C and 1D according to 1A, in groups 2A, 2C and 2D according to 2B and in group 2C according to 2A, where a significant statistical reduction was observed (p <0.01). The Clinical and microbiological efficacy of the CXL treatment is evaluated in our study. CXL treatment, CXL treatment combined with topical antibiotic treatment and topical antibiotic treatment of Pseudomonas Aeruginosa (PA) and Metisilin Rezistant Staphylococcus Aureus (MRSA) keratitis infections led to an effective reduction in the density and severity (of infection), in accordance with the conclusion that we reached. From these results, it is shown that topical antibiotics and CXL potentiate each others effects in the treatment of resistant bacterial keratitis. Key Words: Cornea, Bacterial Keratitis, Cross-Linking