Objective: To study the effects of ultraviolet light combined with riboflavin treatment (corneal collagen-crosslinking, CXL) on infectious control and stromal reconstruction of bacterial keratitis. Methods: Experimental Study. A Staphylococcus aureus rabbit keratitis model was established by injecting Staphylococcus aureus broth into the shallow stromal layer of the right eye cornea of New Zealand white rabbits. Forty-four rabbits that successfully established the model were randomly divided into four groups: corneal collagen cross-linking (CXL) group, antibiotic group, CXL+ antibiotic group and untreated group, with 11 rabbits in each group. Before the treatment and at 3, 7, 14 and 28 days after treatment, slit lamp corneal examination, AS-OCT and in vivo confocal microscopy (IVCM) were performed. Clinical efficacy of different treatments were evaluated at different time points. Parameters including conjunctival hyperemia, corneal ulcer, infiltration, edema, and neovascular. Histopathological examinations of corneal lesions were performed in order to detect the infiltration, inflammatory cells and repair in corneal tissue. Normal data were compared with paired t-test and non-normal data were compared with paired rank sum test before and after treatment. Kruskal-Wallis rank sum test was used to compare 4 groups of data and the generalized estimation equation is used to compare the repeated measurement data at each time point and the comparison between the groups of the treatment groups. Results: After treatment, different time points and specimens for pathological observation, we obtained the following results:Conjunctival hyperemia: in CXL and CXL+ antibiotic groups after treatment for 3 days from treatment before 3 (2, -4) and 3 (2, -3),The reduction was 2 (1, -3) and 2 (1, -2), the difference was statistically significant (Z=-3.91, -5.50; P<0.008); 14 days, the antibiotic group changed from 3 (3, -4) to 2 (1, -2) after treatment, the difference was statistically significant (Z=-5.11, P<0.008); the untreated group had no statistical significance before and after treatment. After 14 days of treatment, the area of corneal ulcer (0.08±0.11) cm(2), (0.07±0.05) cm(2) in CXL group and CXL+ antibiotic group was significantly lower than that before treatment (0.40±0.18) cm(2), (0.49±0.24) cm(2). The difference was statistically significant. Significance (Z=-3.29, -3.64; P<0.008); after 14 days of treatment, after 14 days of treatment, neovascularization in the CXL and CXL+ antibiotic groups began to resolve, 1 (1, -2) and 1 (0, -2) at 7 days of treatment. decreased to 1 (1, -1) and 0 (0, -1), the difference was statistically significant (Z=4.57, 3.80; P<0.012 5); The degree of corneal edema was significantly reduced in the CXL group and the CXL+ antibiotic group at 14 days after treatment, which was reduced from (650±154) μm and (785±255) μm before the treatment to (432±95) μm and (455±109) μm, the difference was statistically significant (t=4.50, 4.92; P=0.00); The density of corneal stromal cells was also reduced from (446±257)/mm(2), (321±145)/mm(2) to (107±66)/mm(2), (114±94)/mm(2), the difference was statistically significant (t=4.15, 4.76; P<0.05). Histopathological observation under light microscope showed that most of the corneal ulcers healed in the CXL group and the CXL+ antibiotic group at 7 days of treatment. The epithelial cells were clearly visible and misaligned, and a small amount of neutrophils in the stromal layer. The upper epithelial layer was treated for 14 days. The cells are arranged neatly, the structure is clear, and the inflammatory cells are significantly reduced. Conclusion: Ultraviolet light combined with riboflavin corneal collagen cross-linking has a certain therapeutic effect on rabbit bacterial keratitis infection control and ulcer repair, and can be used as an auxiliary treatment for antibiotics. (Chin J Ophthalmol, 2018, 54:902-910).
目的： 探讨紫外线联合核黄素角膜胶原交联术（CXL）对兔细菌性角膜炎感染控制及基质修复的作用。 方法： 实验研究。将金黄色葡萄球菌菌液注射于新西兰白兔右眼角膜浅基质层建立金黄色葡萄球菌性兔角膜炎模型。将建模成功的44只兔采用随机数字表法分成4组：CXL组、抗生素组、CXL+抗生素组及未处理组，每组11只。在治疗前及治疗后3、7、14、28 d分别行裂隙灯外眼照相、眼前节OCT和活体共聚焦显微镜（IVCM）检查，对比分析不同治疗方法下兔角膜炎的临床表现评分（结膜充血、角膜溃疡、浸润、水肿、新生血管及角膜基质炎症细胞）和治疗效果；通过病变角膜组织病理学检查观察角膜炎症细胞浸润及组织修复情况。正态资料采用配对t检验进行治疗前后的比较，非正态资料采用配对秩和检验进行治疗前后的比较，Kruskal-Wallis秩和检验对4个组数据进行比较，采用广义估计方程对重复测量资料进行各个时间点以及各个处理组的组间比较。 结果： CXL组和CXL+抗生素组动物结膜充血程度在治疗3 d后由治疗前3（2，-4）和3（2，-3）级减轻为2（1，-3）和2（1，-2）级，差异有统计学意义（Z=-3.91，-5.50；P<0.008）；14 d时抗生素组由治疗前3（3，-4）级变为2（1，-2）级，差异有统计学意义（Z=-5.11, P<0.008）；未处理组在治疗前后，差异均无统计学意义（P>0.008）。治疗14 d后CXL组和CXL+抗生素组角膜溃疡面积（0.08±0.05）、（0.07±0.05）cm(2)较治疗前（0.40±0.18）、（0.49±0.24）cm(2)明显减小，差异有统计学意义（Z=-3.29,-3.64；P<0.008）；治疗14 d后，CXL组和CXL+抗生素组新生血管开始消退，由治疗7 d时的1（1，-2）和1（0，-2）级减少至1（1，-1）和0（0，-1）级，差异有统计学意义（Z=4.57，3.80；P<0.012 5）。CXL组、CXL+抗生素组在治疗后14 d，角膜水肿程度明显减轻，由治疗前的（650±154）、（785±255）μm减轻到14 d时的（432±95）、（455±109）μm，差异有统计学意义（t=4.50，4.92；P=0.00）。角膜基质炎症细胞密度也由（446±257）、（321±145）个/mm(2)，减少至（107±66）、（114±94）个/mm(2)，差异有统计学意义（t=4.15，4.76；P<0.05）。光学显微镜下组织病理学观察CXL组、CXL+抗生素组在治疗7 d时，角膜溃疡大部分愈合，上皮细胞清晰可见、排列不齐，基质层少量中性粒细胞；治疗14 d上皮层完整，基质细胞排列整齐、结构清晰，炎症细胞明显减少。 结论： 紫外线联合核黄素角膜胶原交联术对兔细菌性角膜炎感染控制、溃疡修复具有一定的治疗作用，可作为抗生素治疗的辅助手段。（中华眼科杂志，2018，54：902-910）.
Keywords: Keratitis; Riboflavin; Staphylococcal infections; Ultraviolet therapy.