Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
J Refract Surg. 2011 Jun;27(6):401-7. doi: 10.3928/1081597X-20101201-02. Epub 2010 Dec 1.
To investigate corneal wound healing following ultraviolet-A (UVA)/riboflavin corneal collagen cross-linking (CXL) in rabbit corneas.
Thirty-six rabbits were enrolled in the study. Animals were divided into three treatment groups and corneas were analyzed at 24 hours and 4 weeks postoperatively. Thus, each group had 6 rabbits at each time point. Treatment groups were: 1) standard UVA+riboflavin CXL, 2) UVA alone, and 3) riboflavin alone. One eye of each rabbit served as an untreated control eye. TUNEL assay was performed to detect stromal cell apoptosis. Immunocytochemistry was performed to detect the inflammatory marker CD11b expressed in monocytes and the alpha-smooth muscle actin (SMA) marker expressed in myofibroblasts.
At 24 hours, corneas from the UVA+riboflavin CXL group had significantly more apoptosis than the UVA alone and riboflavin alone groups. Eyes from all three groups had significantly more inflammatory cell influx into the cornea than unwounded controls. Four weeks after the procedure, many corneas in the UVA+riboflavin CXL group had mild haze, but very few SMA-positive myofibroblasts could be detected in the central cornea.
Riboflavin+UVA CXL triggers more anterior keratocyte apoptosis than corneal scrape with UVA alone or riboflavin alone. Inflammation monitored by the monocyte marker CD11b was present, but not statistically different among the three groups. Very little myofibroblast generation could be detected after UVA+riboflavin CXL, indicating that the mild stromal haze associated with this procedure is normally related to transient corneal fibroblast generation rather than more persistent haze due to generation of myofibroblasts.
研究紫外线 A（UVA）/核黄素角膜胶原交联（CXL）治疗后兔眼角膜的伤口愈合情况。
本研究纳入 36 只兔子。动物分为三组，术后 24 小时和 4 周时分析角膜。因此，每组在每个时间点有 6 只兔子。处理组为：1）标准 UVA+核黄素 CXL；2）UVA 单独照射；3）核黄素单独处理。每只兔子的一只眼睛作为未处理的对照眼。TUNEL 检测用于检测基质细胞凋亡。免疫细胞化学用于检测单核细胞表达的炎症标志物 CD11b 和肌成纤维细胞表达的α-平滑肌肌动蛋白（SMA）标志物。
在 24 小时时，UVA+核黄素 CXL 组的角膜凋亡明显多于 UVA 单独照射和核黄素单独处理组。与未受伤对照组相比，三组的角膜都有更多的炎症细胞浸润。术后 4 周时，UVA+核黄素 CXL 组的许多角膜有轻度混浊，但在中央角膜仅能检测到少量 SMA 阳性的肌成纤维细胞。
核黄素+UVA CXL 引起的前角细胞凋亡比单独 UVA 照射或核黄素单独处理更多。通过单核细胞标志物 CD11b 监测到炎症，但三组之间无统计学差异。在 UVA+核黄素 CXL 后几乎检测不到肌成纤维细胞的生成，这表明与该程序相关的轻度基质混浊通常与短暂的角膜成纤维细胞生成有关，而不是由于肌成纤维细胞的生成导致更持久的混浊。
