The Anti-proliferative Effect Of Paclitaxel Polylactic Acid Microsphere On Scarring Of Filtering Passageways In Rabbit Eyes After Trabeculectomy

Objective:To investigate the anti-proliferative effect and safety of paclitaxel polylactic acid microsphere in rabbit eyes after trabeculectomy.Methods:Drug content in aqueous humor was measured regularly with HPLC to investigate the slow-release effect of paclitaxel polylactic acid microsphere. On the preoperative day, the right eyes of forty-eight rabbits were all measured with plunger type tonometer for intraocular pressure and examined with slit-lamp microscope to observe cornea, conjunctiva,anterior chamber, lens and with indirect ophthalmofundoscope to examine eyeground. Forty-eight rabbits received standard trabeculectomy in right eyes. All rabbits were randomly devided into 4 groups: blank control group, standard control group, experimental groupâ… and experimental groupâ…¡, with twelve animals in each group. No topical drug application was performed in the blank control group, while the rabbit eyes of other groups were performed trabeculectomy respectively with 0.3mg/mL MMC, 0.3mg/mL paclitaxel beneath scleral flap and 2.5mg paclitaxel polylactic acid microsphere to place between conjunctiva and sclera. Intraocular pressure were measured with plunger type tonometer; cornea, conjunctiva,anterior chamber, and eyeground were examined; the functional filtrating blebs were observed on the postoperative 7^th, 21^th, 35^th, 49^th day. Four rabbits were separately selected from the rabbits per set to put to death on the postoperative 21^th, 35^th and 49^th day. The eyeballs of these rabbits were extirpated to observe histopathological changes and to be stained by HE, PCNA and Masson. Slit-lamp microscope, indirect ophthalmofundoscope, Flash ERG , corneal endothelium microscope, transmitted electrical microsphere were used to evaluate the safety of paclitaxel polylactic acid microsphere on the postoperativ 7th , 21^th, 35^th, 49^th day.Results : Drug concentration of aqueous humor measurement confirmed the slow-release effect of paclitaxel polylactic acid microsphere. Drug concentration in aqueous humor maintained permanent level for a long time. After operation, no evident adverse reactions were discovered in Experimental groupâ…¡, whereas conjunctiva wound leaks and the injuries of corneal epithelium were discovered in the standard control group. There were less complications in experimental groupâ…¡than that in other three groups. The number of the functional filtrating blebs in experimental groupâ…¡was more and the intraocular pressure was maintained better than that in other three groups. After the use of paclitaxel polylactic acid microsphere in experimental groupâ…¡, the number of inflammatory cells, proliferation of fibroblasts and new collagen fibers significantly decreased compared with the other three groups. The results of slit-lamp microscope, indirect ophthalmofundoscope, Flash ERG, corneal endothelium microscope, transmitted electrical microsphere all displayed that paclitaxel polylactic acid microsphere was safe to the tissues of eye.Conclusions:Drug content of paclitaxel polylactic acid microsphere in aqueous humor could keep permanent level for a long time and possessed slow-release effect. No prominently adverse reactions or complications occurred after implantation between conjunctiva and sclera. Using paclitaxel polylactic acid microsphere between conjunctiva and sclera during trabeculectomy decreased HE, PCNA, Masson expression in proliferating cells and inhibited the formation from scarring of filtering passageways. Meanwhile, it was safe to the tissues of eye. Paclitaxel polylactic acid microsphere would be a usefully anti-proliferative praeparatum applied in glaucoma filtering surgery.