Experimental Study Of Endoscopic Cyclophotocoagulation In Rabbit Eyes

Objective1.To study the histopathologic changes and determine the mechanism of lower intraocular pressure(IOP) after endoscopic cyclophotocoagulation(ECP) in rabbit eyes.2.To determine the effect of lower IOP after ECP, the incidence rate of operative complications after ECP, and compare the results of ECP with that of trans-scleral cyclophotocoagulation(TSCP).MethodWe selected 32 pigmental rabbits randomly and chose two for normal rabbits without doing ECP or TSCP. The others performed ECP on one eye and TSCP on the other eye. After operation, we observed and recorded the inflammatory reactions of eye lids, conjunctiva and lens by slit-lamp and the numerical value of IOP by Schiotz tonometer, and took the eyes of rabbits to pathology examination after operation 1week, 2weeks, 4weeks, 6weeks and 8weeks, to observe pathology changes of ciliary body and the inflammatory reactions of conjunctiva, sclera and cornea.Results1 .IOP of rabbits descend significantly after ECP. 1 day after operation In ECP group the IOP was 19.85 ± 2.68 mmHg, a little bit higher, ascending extent was 0.25%,from 3 day after operation, the IOP was decrease. 4 weeks after operation was 9.55 ± 1.09mmHg, descending extent was 52.65%. 8 weeks after operation was 9.8±0.48mmHg, descending extent was 53.82%. From 1 day to 8 weeks afteroperation, IOP descending extent of ECP was significantly greater than TSCP.2.We found that rabbit ciliary body epithelium were destroyed selectively and obviously by effect of ECP, especially for non-pigment epithelial cell. Compared with the changes of TSCP, the destroy to ciliary epithelium of ECP was more sufficient and the injury to vascular or closed tissue of ECP was more slight.3.The lens of rabbits in ECP group all became different extent lenticular opacity after operation,and there was no improvement with opacity during the following 8 weeks. While the lens of rabbits in TSCP group was similar with that of pre-operation. Inflammatory reactions of TSCP group was more critical than ECP group in early period. Conclusion1. ECP can selectively destroy ciliary epithelium effectively and thoroughly, that is the main reason to reduce IOP.2.Compared with TSCP group, long effect to low IOP in ECP group is much powerful, inflammatory reactions in ECP group is much slight, and operative complications has no difference. The middle and long term effect of reduce IOP in ECP group is better than TSCP group.3.ECP has negative influence on lens and it should be cautious in phakic eyes, it might be at high risk for surgical complications.4.ECP is a new method of surgery, so it need to be learned and adapted before performing, it can be used in different conditions In clinical work. Key word...