Effect of 10-hydroxycamptothecin on functional bleb following antiglaucomatous filtering surgery / 中华实验眼科杂志

ABSTRACT

Background The filtration surgery is the main method of treating glaucoma,which usually fails due to postoperative scarring.The study about application of anti-scarring agents in filtration surgery is a hotspot.Objective This study was to investigate whether topical administration of hydroxycamptothecin (HCPT) could be used to prevent postoperative scarring in after experimental glaucoma filtration surgery,and explore its optimal dose.Metbods Trabeculectomy was performed on the right eyes of 40 New Zealand white rabbits to establish the trabeculectomy animal models.The rabbits were then randomized into normal saline solution group,0.3 g/L mitomycin C(MMC) group,0.3 g/L HCPT group and 1.0 g/L HCPT group based on the intraoperative topical drugs using randomized number table method.The different drugs above-mentioned were put beneath the conjunctival flap and scleral flap for 5 minutes during the surgery.The intraocular pressure (IOP) was measured before and day 1,4,7,14,21 and 28 after the surgery with Icare tonometer,and the filtering area and height were measured under the slit lamp microscope to assess the efficacy of various drugs.The adverse effects were evaluated by examining the responses of the ocular anterior segment and retinal change.The specimens at operative zone were obtained in 7,14 and 28 days after surgery with the size 5 mm×5 mm for the hematoxylin-eosin staining and Masson trichrome staining to estimate the anti-fibrosis effect of various drugs,and to evaluate the survival time of functional bleb.Kaplan-Meier analysis was used to compare the survival time of functional bleb of different groups.The use and care of the animals complied with the Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Committee.Results The IOP was significantly different in the rabbits from different groups among various time points (Fgroup =20.79,P =0.00 ; Ftime =85.34,P =0.00 ; Fiion =2.13,P =0.01).From 1 day through 28 days after operation,the IOPs in MMC group and 1.0 g/L HCPT group were significantly lower than those before operation (all at P＜0.05).The survival time of functional bleb of different groups was (11.3 ±2.8),(19.5 ±2.4),(13.3 ±2.2) and (20.2 ± 4.5) days,respectively,showing a significant difference (log rank =11.92,P ＜ 0.01),with a considerable prolong in the 1.0 g/L HCPT group.No significant change was found in the bleb area and height among the four groups within 7 days after operation,but postoperative 7,14,28 days,the area and height values of bleb were significantly smaller in the normal saline solution group and 0.3 g/L HCPT group compared with the MMC group and 1.0 g/L HCPT group (all at P ＜ 0.05).Histopathological examination showed loosen subconjunctival tissue,less inflammatory cells and weaker collagenous fibrillary staining in the MMC group and 1.0 g/L HCPT group in comparison with the normal saline solution group and 0.3 g/L HCPT group.Conclusions The topical administration of 1.0 g/L HCPT inhibit the inflammatory response and collagen fibrosis and therefore prolong the survival time of functional bleb after glaucomatous filtering surgery.