Retinal Toxicity Evaluation Of Intravitreal Octreotide

Objective:Octreotide is a somatostatin analogue,Mainly used for the treatment of multiple endocrine tumors and the treatment of upper gastrointestinal bleeding.Many recent studies have found that it can inhibit vascular endothelial cell proliferation and secretion, control of intraocular neovascularization, administration approach to the systemic administration of the main studies of topically applied eye little eye retinal drug toxicityrarely reported.To evaluate the effect on the structure and function of retina of rabbits'eyes after Octreotide is injected into vitreous chamber. About the safety of the eye medication.Methods:Twenty-four healthy color adult rabbits were randomized to experimental group(A) and control group(B).Intravitreal injection of the experimental group OA, according to dose divided into A1(0.2mg),A2(0.6mg),A3 (2.0mg) three groups. Intravitreal injection of control group compound sodium chloride injection 0.1ml,1 week,2 week,4 week after injection,respectively in all experimental objects intraocular pressure,slit-lamp,fundus examinization and ERG. The eye-balls at 4 weeks were taken, and tissue structure of retina were observed under light microscope.Repeated measurement data using multivariate analysis of variance on the ERG and intraocular pressure were analyzedResults:1,Fundus examination:the control group and 0.2mg,0.6mg group at 4-week observation period showed no abnormal anterior segment and fundus, while the 2.0mg group two weeks after the injection there were found two experimental eye cataracts.2,intraocular pressure check:the experimental group after the injection, each group had a transient increased intraocular pressure, at 2 weeks after injection is more obvious, but no significant difference compared with the control group.3,ERG examination:Experimental group, three groups of ERG b wave amplitudes were lower in the observation period, compared with the control group were significantly different, with the decrease in dose increased, the largest decline in two weeks time, to observe the end of the A1, A2group, part of the recovery, and A3 group changed little.4,optical microscopy:The control group, Al and A2 group in the observation group during the organizational structure of the retina were normal.A3 group in the observation end of the internal limiting membrane is not continuous, disordered arrangement of ganglion cells, inner plexiform layer edema, inner nuclear layer cells decreased significantly, outer nuclear layer cells also have reduced.Conclusion:Normal rabbit vitreous cavity single injection of octreotide 0.6mg relatively safe, single dose of 2.0mg, and function under the light microscope detection of retinal toxicity occurred in 4 weeks without relief.