Experimental modeling of bacterial keratitis and uveitis

Abstract

When developing new protocols and methods for treating eye diseases, there is a need to set up an experiment with modeling a particular pathology in vivo. Currently, there are several methods for modelling keratitis and uveitis, however, their effectiveness remains unclear. In our research, under the experimental conditions on laboratory animals (rabbits), were applied three action methods of pathological factors causing inflammation and morphofunctional changes in eye tissues. The first method included the effect of ultraviolet exposure for 3 min using a DRT-240 mercury lamp, followed by infecting damaged corneal surface with the pathogenic Staphylococcus aureus strain 1×105 CFU/ml. The second method consisted of the introduction of the S. aureus pathogenic strain by injection of 1×105 CFU/ml into the anterior chamber of the eye. The third method is the application of filter paper 5 mm in diameter and soaked in 1% sodium hydroxide (NaOH) solution for 30 s on the surface of the eye cornea. In order to compare the degree of damage to the eye tissues after using various pathological factors, intravital diagnostic methods were used, in particular, the Shimmer test, the Seidel fluorescence test, non-contact face-to-face tonometry, biomicroscopy in focal light, ultrasound eye diagnostics, photo fixation. On the 7th day of the experiment, the animals were taken out of the experiment and histological studies of the enucleated eyeballs were carried out. It was found that all the factors that were used cause pathological processes, expressed to varying degrees. According to a complex of clinical and histological studies, it was found that the first method turned out to be the most effective, since the exposure of ultraviolet long-wave UVA rays caused a burn, and the next infecting with a pathogenic strain of S. aureus caused the development of total keratitis and uveitis. When a bacterial pathogen was injected into the anterior chamber of the eye, acute inflammation occurred inside the chamber, filling it with purulent exudate and melting the surrounding tissues, but did not cause keratitis on the cornea outer surface. In the group where chemical burns were used, according to the sum of the evaluation criteria and other studies, keratitis was found, but the eye barrier systems prevented the occurrence of uveitis.