Chidambaranathan Gowri Priya, Mathews Saumi, Panigrahi Arun Kumar, Mascarenhas Jeena, Prajna Namperumalsamy Venkatesh, Muthukkaruppan Veerappan
*Department of Immunology and Stem Cell Biology, Aravind Medical Research Foundation, Madurai, India; and †Department of Cornea, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, India.
Cornea. 2015 Nov;34(11):1478-86. doi: 10.1097/ICO.0000000000000593.
Using in vivo confocal microscopy, we established that unique hyperreflective structures in the anterior limbal stroma of healthy individuals represent the limbal stromal niche. The aim of this study was to characterize the limbal stromal microarchitecture in patients with limbal stem cell deficiency (LSCD).
After obtaining informed consent, 10 patients with LSCD and 3 with macular corneal dystrophy were recruited. In vivo confocal imaging of the limbus and cornea of the affected and normal eyes was performed using an HRT III laser scanning microscope, beyond the epithelium deep into the stroma.
In the case of LSCD, the limbal epithelium was replaced by conjunctival epithelium. A large number of inflammatory and dendritic cells were identified along with blood vessels from the epithelium to deep stromal layers. The unique hyperreflective niche structures were replaced by homogenously bright fibrous structures in all eyes with total LSCD. In patients with partial LSCD, even the clinically defined normal limbus had fibrotic stroma. In a patient with focal LSCD, only the affected limbal stroma remained fibrotic, whereas the adjacent clinically normal limbus had the unique hyperreflective structures. Although the opaque corneal stroma appeared bright because of proteoglycan deposition, it was possible to identify the normal limbal epithelial and stromal architecture in macular corneal dystrophy.
In the case of LSCD, the limbal stromal niche was replaced by bright fibrotic structures indicating persistence of damage several months after injury. Further studies are required to characterize the sequential events occurring in the anterior limbal stroma after injury using this noninvasive method.
通过体内共聚焦显微镜检查，我们确定健康个体角膜缘前基质中独特的高反射结构代表角膜缘基质生态位。本研究的目的是描述角膜缘干细胞缺乏症（LSCD）患者的角膜缘基质微观结构。
在获得知情同意后，招募了10例LSCD患者和3例黄斑角膜营养不良患者。使用HRT III激光扫描显微镜对患眼和正常眼的角膜缘和角膜进行体内共聚焦成像，成像深度超过上皮层深入基质层。
在LSCD病例中，角膜缘上皮被结膜上皮取代。从上皮层到深层基质层可识别出大量炎症细胞和树突状细胞以及血管。在所有完全性LSCD的眼中，独特的高反射生态位结构被均匀明亮的纤维结构所取代。在部分性LSCD患者中，即使临床上定义为正常的角膜缘也有纤维化的基质。在一名局灶性LSCD患者中，只有受影响的角膜缘基质仍为纤维化，而相邻的临床上正常的角膜缘具有独特的高反射结构。尽管不透明的角膜基质因蛋白聚糖沉积而显得明亮，但在黄斑角膜营养不良中仍可识别出正常的角膜缘上皮和基质结构。
在LSCD病例中，角膜缘基质生态位被明亮的纤维结构所取代，这表明损伤后数月仍存在持续性损伤。需要进一步研究以使用这种非侵入性方法来描述损伤后角膜缘前基质中发生的连续事件。
