飞秒激光角膜基质透镜用于周边板层角膜移植的实验研究

Application of corneal stromal lenticules in heterogeneous peripheral lamellar keratoplasty in rabbits

目的探讨将全飞秒激光小切口角膜基质透镜取出术中获得的角膜基质透镜用于周边板层角膜移植的方法和技术以及移植术后的结果。方法新西兰白兔10只均分为A、B两组,每组均采用右眼为实验眼,12点至3点钟方位制作周边角膜基质缺损模型。A组采用单纯折叠的方法,B组将纤维蛋白胶涂布于折叠好的透镜组织层间的方法构建板层角膜移植片。A组用10-0尼龙线直接将构建好的板层角膜移植片缝合到右眼植床,而B组则采用纤维蛋白胶将构建好的板层角膜移植片粘合于右眼植床,再用10-0尼龙线缝合。术后观察移植片表面平整度、角膜上皮化完成和维持情况、周边角膜形态、植床和移植片的吻合度、移植片的透明度等指标。观察期末行组织病理学检查。结果两组术后3~5d上皮化均完成,且移植片表面平整,移植片和植床吻合度佳。A组5眼中有4眼移植片均出现新生血管长入,轻、中度水肿混浊,但1个月之后移植片完全透明,新生血管完全消退;A组另1眼在术后10d出现强烈的排斥反应,予眼球摘除。而B组在术后早期5眼中即有4眼移植片发生强烈的异种排斥反应,予眼球摘除;而另1眼的发展过程类似A组4眼,最终移植片完全透明。观察期末组织病理学检查发现A组4眼和B组1眼最终保持透明的移植片内为正常的角膜基质细胞,透镜层间融合良好,植床和移植片交界处有少许散在单核淋巴细胞和成纤维细胞;A组1眼和B组4眼出现类似化脓样的白色浸润病灶,有大量堆积的单核淋巴细胞在透镜层间和表面,并在移植片表面出现组织坏死脱落。结论利用飞秒激光小切口角膜基质透镜取出术中获得的角膜基质透镜经冰冻保存后用于构建周边板层角膜移植片,并将其用于周边板层角膜移植术是可行有效的,因纤维蛋白胶来源于人纤维蛋白可增加异种排斥反应。

Objective To evaluate the application of cryopreserved lenticules extracted from small incision lenticuleextraction （SMILE） surgery in heterogeneous peripheral lamellar keratoplasty in of rabbits with peripheral corneal stromal defect.Methods Ten New Zealand white rabbits were randomly divided into2 groups. Peripheral corneal stromal defect model wasconstructed in right eye of each rabbit. Two layers of cryopreserved lenticules were stacked up for use. In group A, the two-layergraft was sewed to the right eyes. In group B, fibrin glue was coated between the two layers to prepare the graft, and the graftand plant bed were adhered with glue before sewing. The smoothness of graft, corneal reepithelialization status, peripheralcorneal condition, the graft-host fitness, and the transparency of the graft were observed. Histopathological examinations wereconducted in the end of observation. Results Both groups had complete reepithelialization, smooth graft surface and goodgraft-host fitness were observed 3-5 days after operations. Four grafts in group A and1 graft in group B were completelytransparent in1 month, and histopathological examination showed normal corneal stromal cells in these eyes. While1 graft ingroupA and 4 grafts in group B had extreme immuno-inflammatory response and enucleation was performed in these eyes.Histopathological examinations showed severe edema, opacity and grey suppurative infiltration. Conclusion The studydemonstrates that the application of cryopreserved lenticules extracted from SMILE surgery appears to be feasible and effectivein heterogeneous peripheral lamellar keratoplasty in rabbits with peripheral corneal stromal defect.