Nonsteroidal anti-inflammatory therapy effectively prevents the development of proliferative vitreoretinopathy in the experiment
Introduction and purpose. Proliferative vitreoretinopathy (PVR) is caused by retinal damage and increased permeability of the blood-ocular barrier. Activation of inflammation, cell migration and proliferation leading to the membrane formation on the surface of the retina in the lesion area, causes blindness. After surgical removal of all membranes the frequency of PVR recurrence is 30 % on average. Therapeutic approaches are not developed. Since inflammation plays a key role in PVR formation, the aim of our study was to justify the use of non-steroidal anti-inflammatory drug lornoxicam for prevention of the development of proliferative vitreoretinopathy. Materials and methods. The work was performed on rats. PVR was modeled by intravitreal injection of dispase, 0,015 U/μl. Intravitreal administration of lornoxicam was performed 20 minutes later, 8 mg/ml. Volume of injections was 2 μl. On the second and the third day of the experiment we performed intraperitoneal injections of the drug in a dose of 230 mg/kg. Intact animals were used as a control group. Enucleation of the eyes was performed on the first, third, seventh and 42th day of the experiment. Results. Lornoxicam reduced the inflammatory response caused by the dispase introduction. It shifted the start of retinal remodeling from the first to the third day of the experiment, restrained a formation of «rosette» structures in the retina (p<0.05), decreased the rate of destruction of photoreceptors by 34 % (p<0.05) and caused twofold decrease (p<0.05) in the severity of photoreceptor changes. Throughout the experiment, the thickness of retinal and choroidal layers among the treated animals was the same as the thickness of retina and choroid of intact rats. The dispase introduction was accompanied by fibrous membrane formation during the period from 7th to 42th day after the beginning of the experiment. Lornoxicam decreased the incidence of membrane formation by 43 % (p<0.05), and the membranes were smaller and contained less fibrotic components. Conclusions. The use of lornoxicam during early period of PVR development reduced the manifestation of signs of inflammation in the eye: it controlled retinal remodeling at all stages of the disease, decreased the incidences of membrane formation by 43 % and significantly reduced the intensity of fibrotic processes in the membranes.