Rajan Madhavan S, Watters Wayde, Patmore Ann, Marshall John
Department of Academic Ophthalmology, Rayne Institute, St. Thomas' Hospital, London, United Kingdom.
J Cataract Refract Surg. 2005 Sep;31(9):1789-801. doi: 10.1016/j.jcrs.2005.02.047.
To develop an in vitro human corneal model to evaluate stromal epithelial interactions following corneal refractive surgical procedures.
Department of Academic Ophthalmology, Rayne Institute, St. Thomas' Hospital, London, United Kingdom.
Fifty-six human donor corneas procured from the eye bank were placed in a specially designed acrylic corneal holder and were cultured using the air-interface organ culture technique for up to 4 weeks. Corneal refractive surgical procedures such as a simple epithelial defect, 4 diopter (D) and 9 D photorefractive keratectomy (PRK), 4 D and 9 D laser-assisted subepithelial keratectomy (LASEK), and 9 D laser in situ keratomileusis (LASIK) were performed on the model. Temporal events in epithelial and keratocyte cell kinetics were evaluated using digital imaging, confocal microscopy, and light microscopy. Two-way analysis of variance and Student t tests were used to assess statistical significance.
Epithelial healing following PRK was completed by 92 hours +/- 10 (SD) at a rate of 0.58 +/- 0.45 mm2/hour. In LASEK, the epithelial flap was replaced by regenerating peripheral epithelium that showed significant delay in epithelial closure (120 +/- 5 hours) with prolonged latency (24 +/- 4 hours, P<.0001) in comparison with PRK. The magnitude of keratocyte loss corresponded to ablation depth, and keratocyte regeneration was dependent on epithelial closure. In comparison, LASIK corneas showed a lesser percentage of keratocyte loss with poor recovery of keratocyte density in the stromal flap. Epithelial viability and keratocyte density were well preserved in the in vitro human model as observed in control corneas for up to 4 weeks.
The temporal events in stromal epithelial interactions in the in vitro human model closely mimicked in vivo observations. The human model further avoided species-specific variations and provided a suitable test bed for evaluating newer algorithms and therapeutic regimens following refractive surgery.
建立一种体外人角膜模型，以评估角膜屈光手术后基质与上皮之间的相互作用。
英国伦敦圣托马斯医院雷恩研究所学术眼科。
从眼库获取的56个人供体角膜被置于一个特别设计的丙烯酸角膜固定器中，并采用气液界面器官培养技术培养长达4周。在该模型上进行了诸如单纯上皮缺损、4屈光度（D）和9 D准分子激光角膜切削术（PRK）、4 D和9 D激光辅助上皮下角膜磨镶术（LASEK）以及9 D准分子原位角膜磨镶术（LASIK）等角膜屈光手术。使用数字成像、共聚焦显微镜和光学显微镜评估上皮细胞和角膜细胞动力学的时间变化。采用双向方差分析和学生t检验评估统计学意义。
PRK术后上皮愈合在92小时±10（标准差）完成，愈合速度为0.58±0.45平方毫米/小时。在LASEK中，上皮瓣被周边再生上皮替代，与PRK相比，上皮闭合明显延迟（120±5小时），延迟期延长（24±4小时，P<0.0001）。角膜细胞丢失的程度与消融深度相对应，角膜细胞再生取决于上皮闭合。相比之下，LASIK角膜的角膜细胞丢失百分比更低，但基质瓣中的角膜细胞密度恢复较差。在体外人模型中，上皮活力和角膜细胞密度在长达4周的时间里如对照角膜一样得到良好保存。
体外人模型中基质与上皮相互作用的时间变化与体内观察结果密切相似。该人模型进一步避免了物种特异性差异，为评估屈光手术后更新的算法和治疗方案提供了合适的试验平台。
