Helies P, Legeais J M, Savoldelli M, Parel J M, Renard G
Laboratoire Universitaire de Recherche en Ophtalmologie, Hôtel-Dieu, Paris.
J Fr Ophtalmol. 1998 May;21(5):351-60.
Designed to avoid postoperative hypotony that often occurs after trabeculectomy and to maintain long lasting filtration, the MESH is a thin porous expended polytetrafluoroethylene (ePTFE) implant that mimics the physiological meshwork. The aim of this study is to assess the tolerance, biocompatibility and effectiveness of this device during 6 months in the rabbit.
We used an ePTFE with about 5 microns pore size (Zytex). The head of the implant is 3,0 mm wide and 1,5 mm long and fits in the anterior chamber. The tail is 2,0 mm wide and 3,0 mm long and fits in the subconjunctival space. The MESH is 250 microns thick. 24 Dutch pigmented rabbits were selected because their dark pigmented iris contrasts with the ePTFE implant giving a better visualization. All the animals were cared for in accordance with ARVO resolutions. Surgery was performed on the right eye by the same surgeon (P.H.), the left eye serving as control for IOP measurements. The animals were distributed in 3 groups: one with MESH alone (MESH), one with MESH and Mitomycin C (MMC), one with MESH and 5-FU (5-FU). Follow-up was performed every week (W) during 6 months including IOP measurement, slit lamp observation, photography and bleb assessment. Histological study was done at POD 0, 15, 30, 90 and 180 one eye in each group. Student t test and alternate Welch t test were used for statistics.
Filtering bleb: no bleb was visible before W3. A bleb was found between W3 and W6, decreasing between W6 and W9 with no more change after W10. The MESH implant: no change appears in the color of the MESH during the study. Some iris pigments or synechiae were seen in some cases. No extrusion occurred. Intraocular pressure: IOP was lower than in the control eye. The statistical analysis showed a significant lower pressure for the MESH alone at W5 (p = 0.0069), for the 5-FU group at W1 (p = 0.0326), W2 (p = 0.0488), W4 (p = 0.0312). With Mitomycine C we found very significant results at W1 (p = 0.0073), W2 (p = 0.0136), W4 (p = 0.0497), W9 and W11 (p = 0.0174). After W12 the groups were joined and IOP was significantly decreased at W17 (p = 0.0376) and W23 (p = 0.0462). Histology confirmed the correct position of the MESH, its biocompatibility and its ability to drain aqueous humor even if there is colonization of the pores by fibroblast-like cells.
The present study has shown that the filtering bleb appeared after 3 weeks without major hypotony. The material was integrated only in the intrascleral tunnel and was stable. After 6 months the Mesh was well tolerated. The new concept has a simple surgical technique, less invasive than trabeculectomy and required less surgical time. This technique reduced IOP and produced long survival blebs in rabbits. This device appears suitable for the surgical treatment of open angle glaucoma.
MESH是一种薄的多孔膨体聚四氟乙烯（ePTFE）植入物，旨在避免小梁切除术后经常出现的术后低眼压，并维持持久的滤过功能，它模仿生理网状结构。本研究的目的是评估该装置在兔体内6个月期间的耐受性、生物相容性和有效性。
我们使用了孔径约为5微米的ePTFE（Zytex）。植入物头部宽3.0毫米，长1.5毫米，适合置于前房。尾部宽2.0毫米，长3.0毫米，适合置于结膜下间隙。MESH厚250微米。选择24只荷兰有色兔，因为它们深色的虹膜与ePTFE植入物形成对比，便于更好地观察。所有动物均按照美国眼科研究协会（ARVO）的决议进行照料。右眼由同一位外科医生（P.H.）进行手术，左眼作为眼压测量的对照。动物分为3组：一组仅植入MESH（MESH组），一组植入MESH和丝裂霉素C（MMC组），一组植入MESH和5-氟尿嘧啶（5-FU组）。在6个月期间每周进行随访，包括眼压测量、裂隙灯观察、摄影和滤过泡评估。在术后第0、15、30、90和180天对每组的一只眼睛进行组织学研究。采用学生t检验和交替韦尔奇t检验进行统计学分析。
滤过泡：在第3周前未见滤过泡。在第3周至第6周发现一个滤过泡，在第6周至第9周减小，第10周后无更多变化。MESH植入物：在研究期间MESH的颜色未出现变化。在某些情况下可见一些虹膜色素或粘连。未发生挤出。眼压：眼压低于对照眼。统计学分析显示，仅MESH组在第5周时眼压显著降低（p = 0.0069），5-FU组在第1周（p = 0.0326）、第2周（p = 0.0488）、第4周（p = 0.0312）时眼压显著降低。对于丝裂霉素C组，在第1周（p = 0.0073）、第2周（p = 0.0136）、第4周（p = 0.
