正常羊眼小梁切除联合滤道成形术的研究

Experimental study a new device of scleral flap stent on filtration surgery in normal Sheep

目的探讨用甲基丙烯酸甲酯（PMMA）材料制成的巩膜瓣支架植入巩膜瓣下的滤道成形术效果。方法选择正常小尾寒羊32只，采用随机数字表法分为实验组或对照组。实验组行巩膜瓣下支架植入术，对照组行单纯小梁切除术。术前和术后连续1年观察其眼压和眼前节变化、超声活体显微镜（UBM）、光镜、电镜检测情况。结果实验组眼压下降幅度明显大于对照组，术后4周对照组眼压基本恢复至原水平，实验组至少延期至术后3个月回复至原眼压水平。UBM检测滤过泡形态：术后1周、1个月，实验组可见植入支架的强回声和大“液间腔”；术后3个月，滤过泡仍较膨松；术后4周，对照组滤过泡低平，滤过道即已闭塞。组织病理学检查结果：术后4周，对照组滤过道已纤维化；实验组术后滤过道延期愈合，3个月时，支架与周围组织仍有间隙；6个月时，此间隙消失，支架与周围组织全部愈合，显示组织相容性好，无排斥现象。病理检查结果与UBM检测结果完全一致。术后1年，实验组未见明显毒、副作用。结论采用PMMA材料制成的巩膜瓣支架植入巩膜瓣下的滤道成形术效果安全、有效，较传统小梁切除术的降眼压效果显著而持久。

Objective To test the effectiveness and safety of a filtering drainage device, a scleral flap stent（SFS） made of poly methyl methacrylate（PMMA） in trabeculectomy（ or filtering drainage-plasty） in sheep. Methods 32 of normal sheep were used. Trabeculectomy was performed in both eyes and the filtering drainage device, a SFS was randomly implanted under the scleral flap in one eye. After the surgery, the intraocular pressure （IOP） was measured by Schiotz tonometer; The filtering blebs and its histopathology was examined by a silt lamp, an ultrasound biomicroscope （UBM） , and electromicroscope. Results The IOP in eyes with traboculectomy plus SFS was statistically significant （ P 〈 0. 001 ） lower than that in eyes with trabeculectomy along at one month （11.38 ± 1.20）mm Hg vs（ 14.05 ±0.93 ）mm Hg and at three months （ 11.95 ± 1.18 ） mm Hg vs （ 15.2 ± 1.09 mm Hg）. Compared to the pre-operation, no difference in IOP was found at one month in eyes with trabeculectomy along（ 16.04 ± 1.02） mm Hg vs （ 14.05 ± 0.93 ）mm Hg. The filtering bleb was lasted more than 3 months in eyes with trabeculectomy plus SFS while existed only one month in eyes with trabeculectomy along by both slit lamp and UBM examination. The fibroblastic proliferation of filtering pathway and scar formation was found at one months post-operation in eyes with trabeculectomy along, however, the fibroblastic proliferation and the scar formation were found at three months and at six months after surgery in eyes with trabeculectomy plus SFS, respectively, by a light and electromicroscopy examination. Tissue compliance was good and no elimination occurred. No toxic or adverse effects were observed in the following year pest-operatively. Condusion SFS is a safe and effective newly designed filtering drainage device in lowering lOP when performed together with trabeculectomy.