Effects of Tacrolimus in experimental proliferative vitreoretinopathy

PVR is the most important reason for the failure of the rhegmatogenous retinal detachment surgery. Nowadays despite the improvements in vitreoretinal surgery, serious problems in the treatment of PVR are still present. Therefore, as a result of the laboratory and clinical studies, it is observed that pharmacological adjuvant treatment can change the proliferative process and increase the success of the surgery. The aim of our study is to investigate the effect of the intravitreal tacrolimus on growth factor and development of PVR.In this study, each containing seven pigmented cavies of three groups were formed. 0.2 ml saline solution was applied intravitreally to the cavies in Group 1(Control). For the cavies in Group 2(Sham) in order to create PVR, 0,07 IU dispase in 0,1 ml and 0,1 ml saline solution was intravitreally applied. For the cavies in Group 3(Treatment), 0,07 IU dispase in 0,1 ml and 25 microgram tacrolimus in 0,1 ml were intravitreally injected. Total of five times intravitreal injection of tacrolimus was performed during the experiment. For the development of PVR, a period of 10 weeks passed. At the end of this period, eyes were enucleated and divided into two in order to perform gross pathological examination. The stages of PVR were identified during the gross pathological examination. Enücleated half of the globe was evaluated for the histopathologically ERM formation, the presence of retinal fold and impairment of photoreceptor cells. The retina of the other half of the globe was separated and by using ELISA method TGF- ß, PDGF, FGF levels were evaluated.The average PVR stages assessing in terms of severe PVR rates, it is observed that treatment group had been significantly improved compared to the sham group. TGF-ß, PDGF, and FGF levels in the treatment group compared to sham group was significantly decreased. ERM formation and retinal fold in the presence of histopathological level in terms of significant improvement is seen in the treatment group. Photoreceptor cells in terms of degradation of a difference between treatment and sham groups were not statistically significant.This study showed intravitreal tacrolimus application can supress PVR development. These results suggest that in PVR prophylaxis tacrolimus may be effective.Key Words: PVR, tacrolimus, growth factors