Surgical and Immunohistochemical Outcomes of Scleral Reconstruction With Autogenic, Allogenic and Xenogenic Grafts: An Experimental Rabbit Model

<b>Purpose</b>: Choukroun’s platelet-rich fibrin (PRF), a second-generation platelet concentrate, has unique morphological and chemical features and may be considered as a scaffold for scleral reinforcement and regeneration. The purpose of this study was to compare the use of xenogenic human-derived amniotic membrane (HAM), allogenic sclera, and autogenic PRF in rabbit lamellar scleral defect model with respect to both anatomical and immunohistochemical improvement. <b>Methods</b>: A total of 45 adult New Zealand rabbits were randomized into 5 groups: normal control; without surgical procedure, negative control; scleral defect model (SDM), xenogenic HAM; SDM+HAM graft, allogenic sclera; SDM+allogenic sclera graft, autogenic PRF; SDM+autogenic PRF graft. Clinical findings, Hematoxylin&amp;Eozin (HE), Masson Trichrome, Verhoeff Acid Fuchsin, Transforming Growth Factor β Receptor 1, Fibroblast Growth Factor, Bone Morphogenetic Protein 2, collagen type 1, aggrecan, and Matrix Metalloproteinase 2 were evaluated. <b>Results</b>: Ocular surface inflammation was significantly lower in normal control and autogenic PRF groups (p&lt;0.001). Graft was avascular and not integrated to scleral wound area in 25% rabbits of allogenic sclera group (<i>p</i>=0.02), was out of the scleral wound in 33.3% rabbits of xenogenic HAM group (<i>p</i>&gt;0.05), all the grafts were at the normal location and viable in autogenic PRF group. The inflammation and vascularization in autogenic PRF group was significantly lower than negative control and xenogenic HAM groups in HE (<i>p</i>&lt;0.001). The collagen score of negative control and xenogenic HAM groups were significantly lower than normal control (<i>p</i>&lt;0.001) and autogenic PRF (<i>p</i>&lt;0.001) groups. There were insignificant differences between allogenic sclera and autogenic PRF groups (p&gt;0.05). For immunohistochemistry, the closest values to normal control group were detected in autogenic PRF group for all immunomarkers. <b>Conclusion</b>: Autogenic PRF showed superior features via its excellent anatomical and chemical composition for scleral regeneration when compared to single-layered xenogenic HAM and allogenic sclera grafts.

<b>研究目的</b>：Choukroun富血小板纤维蛋白（platelet-rich fibrin, PRF）作为第二代血小板浓缩物，具有独特的形态学与化学特性，可作为巩膜加固与再生的支架材料。本研究旨在比较异种人源羊膜（xenogenic human-derived amniotic membrane, HAM）、同种异体巩膜与自体PRF在兔板层巩膜缺损模型中的应用效果，从解剖学与免疫组织化学两个维度评估其改善情况。
<b>研究方法</b>：将45只成年新西兰兔随机分为5组：正常对照组（未实施任何手术操作）、阴性对照组（仅建立巩膜缺损模型，scleral defect model, SDM）、异种羊膜组（SDM+异种人源羊膜移植）、同种异体巩膜组（SDM+同种异体巩膜移植）以及自体PRF组（SDM+自体PRF移植）。本研究对临床指标、苏木精-伊红（Hematoxylin&Eozin, HE）染色、马松三色（Masson Trichrome）染色、维尔霍夫酸性复红（Verhoeff Acid Fuchsin）染色、转化生长因子β受体1（Transforming Growth Factor β Receptor 1）、成纤维细胞生长因子（Fibroblast Growth Factor）、骨形态发生蛋白2（Bone Morphogenetic Protein 2）、Ⅰ型胶原（collagen type 1）、聚集蛋白聚糖（aggrecan）以及基质金属蛋白酶2（Matrix Metalloproteinase 2）的表达情况进行了评估。
<b>研究结果</b>：正常对照组与自体PRF组的眼表炎症程度显著更低（<i>p</i><0.001）。同种异体巩膜组中有25%的兔移植物无血管形成且未与巩膜创面整合（<i>p</i>=0.02）；异种羊膜组中有33.3%的兔移植物脱离巩膜创面（<i>p</i>>0.05）；而自体PRF组的所有移植物均位于正常位置且存活良好。HE染色结果显示，自体PRF组的炎症反应与血管化程度显著低于阴性对照组与异种羊膜组（<i>p</i><0.001）。阴性对照组与异种羊膜组的胶原评分显著低于正常对照组（<i>p</i><0.001）与自体PRF组（<i>p</i><0.001）；同种异体巩膜组与自体PRF组之间无显著差异（<i>p</i>>0.05）。免疫组织化学检测结果显示，自体PRF组的所有免疫标志物表达水平均最接近正常对照组。
<b>研究结论</b>：与单层异种人源羊膜及同种异体巩膜移植物相比，自体PRF凭借其优异的解剖学特性与化学组成，在巩膜再生方面展现出更优的性能。