An Animal Model Foundation Of Suprachoroidal Hemorrhage In Rabbits

Objective: To investigate the method and safety of the model foundation of suprachoroidal hemorrhage (SCH) in rabbit eyes, and to observe its natural course for the purpose of offering the theory of retinal damage by suprachoroidal hemorrhage and analyzing the relative factors.Methods: Fourteen adult and healthy rabbits were included in this study, among which 2 rabbits (4 eyes) were in control group and 12 rabbits (24 eyes) were in experimental group. The latter were randomly divided into 6 groups according to the different examination time. Auto-anticoagulation blood 0.lml was injected into the suprachoroidal space through the full-thick scleral incision in the experimental rabbit eyes under the operating microscope. There was no adjunct in control group, and the rabbits in the control were only served as the comparison of the changes of the retina and ciliary body histologically and ultrasonographically. Under microscope a trapezoid flap was made in the conjunctiva with the base of fornix supranasally or supratemporally, and then a full thick tunnel incision was made in the sclera by 11 gauge blade 10 mm posterior and parallel to the limbus with the incision 1mm long and the tunnel 1 mm long. About 0.1 ml aqueous humor was aspirated through the puncture of the anterior chamber made by the comeal puncture blade, at the same time 0.1 ml rabbit blood was injected into the suprachoroidal space through the incision slowly with 1 ml syringe, and the sclerotomy was opressed with cotton swab for 1 minute. The conjunctival flap4was replaced and sutured. 0floxacin 0.1% eye drops was used 3 times a day. Direct and indirect ophthalmoscope, fundus photography, A/B ultrasonography, and histopathologic examinations were performed at 1 hour, 1, 3, 7, 14, and 21 days postoperatively.Results: SCH occurred in all rabbit eyes in the experimental group. (1) The retina and the choroid were eminenced obviously under the fundus examination 1 hour postoperatively, which areas ranged from 8 to 10 disc diameter (DD) with a clear and smooth border at the surrounding retina and choroid. The areas of SCH extended, the eminence degree decreased with vague border 1 day postoperatively, and tortuosity and dilation occurred in the retinal vein. The retinal vein was the same as that in the first day, the blood was began to be absorbed 3 days with uneven color in the area, and mostly absorbed after 7 days with some small patches of blood remained and completely absorbed 21 days postoperatively when the retina and the choroid returned to the normal state. (2) SCH was proved by A/B ultrasonography. On A-scan the raised peak emerged in the vitreous and between which and the peak of posterior eye wall there were some small dense waves. On B-scan the strong echo area occurred in the black vitreous area and obviously bulgeed to the vitreous cavity hemispherically with clear and smooth border in which there were massive light spots. The strong echo area and the strong echo light spots in which decreased obviously 7 days postoperatively, and disappeared completely 21 days postoperatively with coarse echo of posterior eye wall in the area of SCH. (3) Inflammatory cell infiltration was seen in thesuprachoroidal space during the period of 1 to 3 days after the operation histophysilogically. The blood began to be absorbed at the third day and hemolyzed incompletely at the seventh day. The blood was totally hemolyzed and vacuolation degeneration was occurred in the rod and cone cell layer 14 days postoperatively, and which became more obvious 21 days postoperatively. The dilation and congestion of the capillary were seen in the ciliary process 1 hour postoperatively and gradually disappeared. The ciliary processes were atrophied 14 days and become more obvious 21 days postoperatively. In control group, the retina and the ciliary remained unchanged.Conclusion: (1) The method of SCH model foundation in rabbits eyes by injecting auto-anticoagulation blood into the suprachoroidal space through the full-thick scleral incision was simple, practical,...