Manetti Mirko, Favuzza Eleonora, Sgambati Eleonora, Mencucci Rita, Marini Mirca
Department of Experimental and Clinical Medicine, Section of Anatomy and Histology, University of Florence, Largo Brambilla 3, 50134 Florence, Italy.
Eye Clinic, Department of Surgery and Translational Medicine, University of Florence, Largo Brambilla 3, 50134 Florence, Italy.
Acta Histochem. 2017 Apr;119(3):343-347. doi: 10.1016/j.acthis.2017.02.001. Epub 2017 Feb 16.
The standard corneal collagen cross-linking (CXL), that includes the removal of corneal epithelium to permit adequate penetration of riboflavin in the stroma, is an established procedure to halting keratoconus progression. However, as epithelial removal may cause postoperative pain and an increased risk of corneal infection, new therapeutic approaches have been proposed. Iontophoresis is a recently developed non-invasive technique which provides the use of electrical current during CXL to enhance transepithelial penetration of riboflavin into the corneal stroma. Here, we describe for the first time the morphological changes of the corneal stromal compartment in a patient with keratoconus who underwent in vivo iontophoresis-assisted CXL (ionto-CXL) before full-thickness corneal transplantation. Immunohistochemistry for type I collagen and CD34 was performed to investigate the stromal distribution of collagen fibers and keratocytes, respectively. The histology of ionto-CXL-treated keratoconic cornea, collected 6 months after the intervention, was compared with that of healthy corneas and either untreated or standard CXL-treated keratoconic corneas. An attempt to restore a normal stromal architecture was observed in the ionto-CXL-treated cornea compared with untreated keratoconic corneas. In particular, the ionto-CXL-treated cornea showed a parallel distribution of type I collagen fibers, although fiber interweaving appeared less organized than in healthy corneas and standard CXL-treated keratoconic corneas. Moreover, the distribution of CD34-positive keratocytes was improved in keratoconic corneas following ionto-CXL treatment, though a scattered CD34 immunoreactivity was still noticeable in the subepithelial stroma. This study provides histological evidence that ionto-CXL may represent a non-invasive alternative in the management of progressive keratoconus in adults.
标准的角膜胶原交联术（CXL），包括去除角膜上皮以允许核黄素充分渗透到基质中，是一种已确立的阻止圆锥角膜进展的方法。然而，由于去除上皮可能会导致术后疼痛和角膜感染风险增加，因此人们提出了新的治疗方法。离子电渗疗法是一种最近开发的非侵入性技术，它在CXL过程中利用电流增强核黄素经上皮渗透到角膜基质中。在此，我们首次描述了一名圆锥角膜患者在全层角膜移植前接受体内离子电渗疗法辅助CXL（离子电渗CXL）后角膜基质层的形态学变化。分别进行了I型胶原和CD34的免疫组织化学检测，以研究胶原纤维和角膜细胞的基质分布。将干预6个月后收集的离子电渗CXL治疗的圆锥角膜组织学与健康角膜以及未治疗或标准CXL治疗的圆锥角膜组织学进行比较。与未治疗的圆锥角膜相比，在离子电渗CXL治疗的角膜中观察到了恢复正常基质结构的尝试。特别是，离子电渗CXL治疗的角膜显示I型胶原纤维呈平行分布，尽管纤维交织看起来比健康角膜和标准CXL治疗的圆锥角膜更无序。此外，离子电渗CXL治疗后圆锥角膜中CD34阳性角膜细胞的分布有所改善，尽管在角膜上皮下基质中仍可明显看到散在的CD34免疫反应性。这项研究提供了组织学证据，表明离子电渗CXL可能是成人进行性圆锥角膜治疗中的一种非侵入性替代方法。
