The impact of octreotide in experimental proliferative vitreoretinopathy

Abstract

Aims:This study aims to investigate the effects of intravitreal octreotide on the growth factors, which have significant roles in the pathogenesis of proliferative vitreoretinopathy (PVR).Settings and Design:An experimental trial.Materials and Methods:21 guinea pigs were randomly assigned to form 3 groups each including 7 animals. In group 1 (the control group), 0.2 ml saline solution was applied intravitreally in a location of 1.5 mm behind the limbus. In group 2 (the sham group), 0.07 IU dispase in 0.1 ml and 0.1 ml saline solution were applied via the same route. The guinea pigs in group 3 (the treatment group) were applied 0.07 IU dispase in 0.1 ml and 1 mg octreotide in 0.1 ml via the same route. Octreotide injection was applied twice during the period of 10 weeks of the experiment. At the end of the 10 weeks, eyes were enucleated and retinal homogenates were prepared. The platelet derivated growth factor (PDGF), insulin-like growth factor (IGF 1) and transforming growth factor (TGF ß) levels in homogenized retina tissue were measured by Enzyme Linked-Immuno-Sorbent Assay (ELISA) method.Statistical Analysis Used:Kruskal-Wallis variance analysis and Mann-Whitney U test.Results:In the treatment group, a significant decrease was observed in retinal PDGF levels (P < 0.01) while decreases in TGF ß and IGF 1 levels were not found to be significant (P > 0.05).Conclusions:Intravitreally applied octreotide at a dose of 1 mg has a highly strong effect on PDGF. This study suggests that intravitreal octreotide may suppress PVR development and that octreotide may merit investigation for PVR prophylaxis.

Animal Models of Proliferative Vitreoretinopathy and Their Use in Pharmaceutical Investigations

“…Multiple medical treatments have been used to prevent inflammation (the first phase of PVR) and inhibit cell proliferation (the second phase) [1]. Tested medical agents include: (1) corticosteroids and other anti-inflammatory agents [6-8]; (2) 5-fluorouracil, vincristine, doxorubicin, cisplatin, dactinomycin, bleomycin sulfate, etoposide, mitomycin, cytarabine, daunorubicin, adriamycin, 2’-benzoyloxycinnamaldehyde [9-11], methotrexate [12, 13], and other antineoplastic drugs to prevent the proliferative response of PVR; (3) retinoic acid [14], matrix metalloproteinase inhibitors [15], and other agents with specific antiproliferative targets; (4) compounds that specifically target growth factors or their pathways, such as hypericin (an inhibitor of the protein kinase C pathway [16]); herbimycin A [17] and dasatinib (tyrosine kinase inhibitors) [18]; tranilast (a potent inhibitor of transforming growth factor [TGF]-β [19]), LY-364947 (a TGF-β receptor 1 inhibitor [20]); taxol (a drug that stabilizes microtubules and may therefore inhibit cell contractility [21]); colchicine (inhibits the formation of microtubules as well as inhibiting fibroblast proliferation [22]) and suramin (an antiparasitic agent that interferes with growth factor binding [23]); and (5) other bioactive factors or compounds like octreotide [24] and resveratrol [25]. …”