Pharmacokinetics and efficacy of Bioerodible Dexamethasone implant in Concanavalin A-induced uveitic cataract rabbit model

Nonsteroid anti-inflammatory therapy suppresses the development of proliferative vitreoretinopathy more effectively than a steroid one

PURPOSE

This study proves the possibility of targeted use of the nonsteroidal anti-inflammatory drug lornoxicam to prevent the development of proliferative vitreoretinopathy (PVR). Triamcinolone acetonide (TA) was selected as a reference substance.

METHODS

Wistar rats (N = 400) were used. PVR was modeled by intravitreal injection of dispase or concanavalin A. Lornoxicam or TA intravitreal administration was performed 20 min later. On the second and the third day, drugs were administrated systemic. Enucleation was performed on the first, third, seventh and 42nd or 56th day of the experiment.

RESULTS

Pro-inflammatory substances led to the development of sub- and epiretinal membranes. Lornoxicam decreased the incidence of membrane formation by 43 and 31% in dispase and concanavalin models, respectively. Membranes, formed during its use, were smaller and contained less fibrotic components. At the end of the experiment, the thickness of retinal and choroidal layers among the animals which had received the therapy was the same as the thickness of the retina and choroid of intact rats. Lornoxicam administration normalized the cyclooxygenases (COXs) expression in the retina and the choroid at the early stages of the experiment. TA application was less effective in both models.

CONCLUSIONS

COXs blocking during the development of PVR, overwhelming inflammation in the eye and reducing its consequences, is proved to be a much more effective and safe influence than the suppression of the entire cascade of arachidonic acid metabolism. Lornoxicam did not only improve the condition of the retina and the choroid but also significantly reduced the frequency of membrane formation.