The effect of infliximab and octreotide on cytokine levels experimental proliferative vitreoretinopathy

Proliferative vitreoretinopathy is a serious disorder that is characterized by the active development of cellular proliferation and tractional retinal detachment. In the treatment of PVR in many cases the result for visual acuity is not satisfactory despite advances in surgical equipment and vitreoretinal surgical techniques. The aim of this study was to investigate the efficiency of intravitreal octreotide and infliximab on cytokine levels which plays important role in the pathogenesis of PVR and development of PVR. Pigmented twenty-eight guinea pigs were divided into 4 groups each group consists of seven subjects. Group 1 (control) treated with 0.2 ml saline solution intravitreally from 1.5 mm behind the limbus. Group 2 (sham) was treated with 0.07 IU/0.1 ml dispase 0.1 ml saline solution using the same method. Group 3 (infliximab) was treated with 0.07 IU / 0.1 ml dispase and 1 mg/0.1ml infliximab using the same method. The subjects in group 4 (octreotide) was treated with 0.07 IU/0.01ml dispase and 1 mg/0.1ml octreotide using the same method. Group 3 and 4 was administered intravitreal injection of infliximab and octreotide for two times during the experiment. The 10-week period for formation of PVR awaited. Eyes were enucleated and divided into two sections, at the end of the experiment one half of the globe were stained with hematoxylin-eosin and evaluated for the epiretinal membrane formation, the presence of caryopycnosis in ganglion cells, deterioration of photoreceptor cells, and presence of retinal fold were examined histopathologically, on the other hand the other half of the globe was used for IL-1, IL-6, TNF-?, TGF-ß and PDGF levels in the retina. In the infliximab group significant improvement was observed histopathologically in terms of deterioration of photoreceptor cells and epiretinal membrane formation compared with sham group (p = 0.031, p=0.018). On the other hand in the octreotide group significant improvement was found only in terms of deterioration of photoreceptor cells compared with sham group (p = 0.031). Retinal TNF-?, IL-1, IL-6 and PDGF levels were significantly decreased in treatment groups compared to sham (p <0.05). The decrease in the level of TGF-ß was not statistically significant between treatment and the sham group (p> 0.05). As a result, intravitreal infliximab and octreotide can inhibit the development of PVR and reduce levels of cytokine which play an important role in the pathogenesis of PVR. Further studies are needed to determine the usage of these drugs clinically for PVR prophylaxis and treatment as an adjuvant pharmacological agent. Key words: Proliferative vitreoretinopathy, infliximab, octreotide