Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Microsc Res Tech. 2013 Jan;76(1):86-93. doi: 10.1002/jemt.22140. Epub 2012 Oct 17.
To investigate the changes in the ultrastructural architecture of hydrated corneoscleral button (HCSB) and hydrated corneal button (HCB).
Corneoscleral buttons (n = 4) and corneal buttons (n = 4) were hydrated in deionized water for 24 and 48 h and were fixed in 2.5% glutaraldehyde containing cuprolinic blue in sodium acetate buffer and processed for electron microscopy. The tissue was dehydrated and embedded in TAAB 031 resin. Normal CSB and CB were also processed using the same method. Ultrathin sections were stained with uranyl acetate and lead citrate. The sections were observed under JEOL 1400 transmission electron microscope.
In both HCSB and HCB, the lamellae were disorganized and proteoglycans (PGs) were degenerated and detached from the collagen fibrils (CFs). In the HCSB samples, interfibrillar spacing increased but the diameter of the CF had not changed compared with those in the normal tissue. Within the HCSB, the interfibrillar spacing in the posterior stroma was significantly higher compared with those in the anterior and middle stroma. In the HCB, both the interfibrillar spacing and CF diameter had significantly increased compared to those observed in both the HCSB and normal tissue. The CFs were severely damaged exhibiting very thin microfilaments within CFs. Remnants of the CFs were present in the stromal matrix.
Hydration of the cornea in both the HCSB and HCB increases the interfibrillar spacing in the anterior, middle, and posterior stroma. The CF in the HCB was enlarged and had degenerated. This could be due to penetration of water into the intermolecular spacing within the CF.
研究去离子水浸泡后脱水角膜缘-巩膜瓣（HCSB）和脱水角膜瓣（HCB）超微结构的变化。
将角膜缘-巩膜瓣（n=4）和角膜瓣（n=4）分别置于去离子水中浸泡 24 小时和 48 小时，用戊二醛固定液（含 Cuprolinic Blue 乙酸钠缓冲液）固定，然后进行电子显微镜检查。组织经脱水后，包埋于 TAAB 031 树脂中。使用相同的方法处理正常角膜缘-巩膜瓣和角膜瓣。超薄片用醋酸铀和柠檬酸铅染色。在 JEOL 1400 透射电子显微镜下观察切片。
在 HCSB 和 HCB 中，板层结构排列紊乱，糖胺聚糖（PG）从胶原纤维（CF）上变性、脱落。与正常组织相比，HCSB 样本中纤维间的间距增加，但 CF 的直径没有变化。在 HCSB 后基质中，纤维间的间距显著高于前、中基质。在 HCB 中，纤维间的间距和 CF 直径均显著高于 HCSB 和正常组织。CF 严重受损，CF 内可见非常细的微丝。CF 残留在基质中。
HCSB 和 HCB 中的角膜水化增加了前、中、后基质中的纤维间间距。HCB 的 CF 增大并变性，这可能是由于水渗透到 CF 内的分子间间隙中所致。
