Clinical and histopathological study of a hollow and posteriorly multiperforated polymethylmethacrylate implant in eviscerated rabbit eyes

ABSTRACT Purpose: The study aimed to evaluate the clinical and tissue response to a hollow polymethylmethacrylate orbital implant with a multiperforated posterior surface in an animal model after evisceration. Methods: Sixteen New Zealand rabbits had their right eye eviscerated. All animals received a hollow polymethylmethacrylate implant 12 mm in diameter that is multiperforated in its posterior hemisphere. The animals were divided into four groups, and each one had the eye exenterated at 7, 30, 90, and 180 days post-evisceration. Clinical signs were assessed daily for 14 days post-evisceration and then every 7 days until 180 days. Inflammatory pattern, collagen structure, and degree of neovascularization generated with implant placement were analyzed with hematoxylin-eosin, picrosirius red, and immunohistochemistry staining. Results: There were no signs of infection, conjunctival or scleral thinning, or implant exposure or extrusion in any animal during the study. On day 7, the new tissue migrated into the implant and formed a fibrovascular network through the posterior channels. Inflammatory response reduced over time, and no multinucleated giant cells were found at any time. Conclusion: Hollow polymethylmethacrylate orbital implants with a multiperforated posterior surface enable rapid integration with orbital tissues by fibrovascular ingrowth. We believe that this orbital implant model can be used in research on humans.摘要 目的：本研究旨在评估眼内容剜出术后，带有多孔后表面的中空聚甲基丙烯酸甲酯（Polymethylmethacrylate，PMMA）眼眶植入物在动物模型中的临床与组织反应。方法：选取16只新西兰兔，对其实施右眼眼内容剜出术，所有受试动物均植入直径12mm、后半球带有多孔结构的中空聚甲基丙烯酸甲酯眼眶植入物。将实验动物分为四组，分别于术后7、30、90及180天处死并获取相关组织样本。术后14天内每日评估临床体征，之后每7天评估一次直至术后180天。采用苏木精-伊红（Hematoxylin-Eosin）染色、天狼星红（Picrosirius Red）染色及免疫组织化学（Immunohistochemistry）染色，分析植入术后的炎症模式、胶原结构及新生血管化程度。结果：本研究期间，所有受试动物均未出现感染、结膜或巩膜变薄、植入物暴露或脱出等异常征象。术后第7天，新生组织侵入植入物内部，并通过后半球的多孔通道形成纤维血管网络。炎症反应随时间推移逐渐减轻，各观测时间点均未发现多核巨细胞。结论：带有多孔后表面的中空聚甲基丙烯酸甲酯眼眶植入物可通过纤维血管长入实现与眼眶组织的快速整合。我们认为该眼眶植入物模型可应用于人类相关研究。