兔眼青光眼滤过术联合巩膜瓣下M型支架植入的研究

Filtering operation combined with M type PMMA frame implantation under scleral flap in rabbit with glaucoma

目的通过建立兔眼小梁切除联合巩膜瓣下植入M型不可降解聚甲基丙烯酸甲酯(polymethylmethacrylate,PMMA)支架的青光眼滤过手术实验模型,探讨这种房水引流植入物的有效性和手术方式的可行性。方法选取正常健康家兔24只左眼行滤道成形术作为滤道成形术组,右眼行单纯小梁切除术作为小梁切除术组。比较滤道成形术和小梁切除术术前以及术后不同时间点(3d、7d、14d)眼压和滤过泡的变化,并同时应用超声生物显微镜(ultrasound biomicroscopy,UBM)观测房水滤过通道的变化。结果(1)滤道成形术与小梁切除术的眼压比较:术前分别是(15.1±1.6)mmHg(1kPa=7.5mmHg)和(15.3±2.0)mmHg;滤道成形术组术后3d、7d、14d眼压分别为(7.8±1.4)mmHg、(8.1±2.0)mmHg、(11.5±2.5)mmHg,小梁切除术组术后对应的时间点分别为(9.8±1.8)mmHg、(10.4±2.2)mmHg和(12.8±1.7)mmHg。滤道成形术组与小梁切除术组在术前、术后14d眼压比较差异无统计学意义(P均>0.05),在术后3d、7d时差异均有统计学意义(P均<0.05)。滤道成形术组术后3d、7d、14d眼压分别与术前比较,差异均有显著统计学意义(P均<0.01),3d时眼压下降幅度最大,降幅为48.4%;术后3d、7d分别与术后14d眼压比较,差异均有统计学意义(P均<0.05)。小梁切除术组术后3d、7d、14d眼压分别与术前比较,差异均有统计学意义(P均<0.05),眼压下降幅度3d时最大,降幅为36.0%;术后3d、7d、14d各时间点之间眼压比较差异均无统计学意义(P均>0.05)。(2)滤道成形术与小梁切除术后滤过泡的大小无明显差别,均在低级和中级之间;UBM检查发现滤道成形术组术后3d、7d可以见到呈白色强回声的PMMA支架及明显的房水滤过间隙,呈黑色低回声区,术后14d仍然可见。小梁切除术后3d可见呈黑色低回声区的房水滤过间隙形成,而术后7d和14d几乎不可见。结论无论实验性青光眼滤道成形术还是小梁切除术,术后眼压均较术前有显著意义的下降。滤道成形术后各时间点眼压的降幅均大于小梁切除术后,说明M型PMMA支架植入可以维持巩膜瓣下房水滤过空间,在一定程度上增强了手术效果。

Objective To discuss efficiency of non-degradable M type polymeth- ylmethacrylate（PMMA） frame and feasibility of surgical manner through building trabe- culectomy combined with this support implanting under the scleral flap（ named filtering pathway plasty） in rabbit models. Methods About 24 normal healthy rabbits,filtering pathway plasty was performed in left eye and trabeculectomy was performed in right eye. The changes of IOP and filtering bleb preoperative and at postoperative 3 days, 7 days, and 14 days were compared between filtering pathway plasty and trabeculectomy, and the filtering pathway space changes were observed using ultrasound biomicroscopy （UBM）.Results （1）IOP were （15.1±1.6）mmHg（1 kPa=7.5 mmHg）,（15.3 ±2. 0） mmHg before filtering pathway plasty and trabeculectomy, were （7.8 ±1.4） mmHg, （ 8.1±2.0 ） mmHg, （ 11.5 ± 2.5 ） mmHg at 3 days,7 days and 14 days after filtering path- way plasty, and were（9.8 ±1.8） mmHg, （ 10.4 ± 2.2） mmHg, （ 12.8 ±1.7） mmHg at 3 days,7 days and 14 days after trabeculectomy, respectively. There was no statistically significant difference in lOP preoperative and at postoperative 14 days between filtering pathway plasty and trabeculectomy （ both P 〉 0.05 ）, but there was statistically significant difference in IOP at postoperative 3 days and 7 days （ both P 〈 0.05 ）. There was significant difference in lOP at 3 days,7 days and 14 days after filtering pathway plasty compared to IOP preoperative（ all P 〈 0.01 ）. The range of lOP decrease was to the best at 3 days by 48.4%. There was statistically significant difference in IOP at postoperative 3 days and 7 days compared to 14 days, respectively（ both P 〈 0.05 ）. There was statistical difference in IOP at 3 days, 7 days and 14 days after trabeculectomy compared to IOP preoperative （ all P 〈 0.05 ）. The range of lOP decrease was to the best at 3 days by 36.0% after trabeeulectomy. There was no statistically significant difference in IOP among postoperative 3 days,7 days and 14 days （ all P 〉 0.05 ）. （ 2 ） There was no significant difference between filtering pathway plasty and trabeculectomy in filtering blebs scope, which was between low and middle grade;Strong echoes of PMMA frame and clearly dark weak echoes of aqueous humor filtering space were shown at 3 days and 7 days using UBM after filtering pathway plasty,and soil shown at 14 days. Clearly dark weak echoes of aqueous humor filtering space were shown at 3 days after trabeculectomy,but almost not seen at 7 days and 14 days. Conclusions There are statistically significant decreases in IOP postoperative compared to IOP preoperative whether for fil-tering pathway plasty or trabeculectomy. IOP decreases at different time points of filtering pathway plasty are more than those of trabeculectomy, which shows PMMA frame can maintain aqueous humor filtering space under scleral flap and im- prove the effects of surgery at a certain extent.