摘要目的:评估核黄素/紫外线A胶原角膜交联术(CXL)治疗薄角膜圆锥角膜患者术后的长期疗效.方法:前瞻性研究.收集2015年1—7月因圆锥角膜于山东大学附属省立医院眼科行CXL治疗的患者19例(32眼),其中男12例(21眼),女7例(11眼).以角膜基质厚度400μm为分界线,将圆锥角膜患者分为薄角膜组和厚角膜组.薄角膜组使用低渗性核黄素溶液进行角膜交联术治疗,厚角膜组使用等渗核黄素溶液进行CXL治疗,术后随访3年,观察角膜最大K(Kmax)值、裸眼视力(UCVA)、最佳矫正视力(BCVA)、最薄处角膜厚度(TCT)、眼压及角膜内皮细胞计数(ECD)等参数变化.采用重复测量方差分析、t检验、Wilcoxon符号秩和检验、Mann-Whitney U检验进行数据处理.结果:薄、厚角膜组术后Kmax值随时间延长均持续降低(F=24.364,P<0.001;F=10.427,P=0.001);薄角膜组术前,术后1、2、3年Kmax值分别为(60.51±6.11)D、(57.43±6.82)D、(56.13±6.85)D、(54.97±6.66)D,术后各时间点与术前相比差异均有统计学意义(t=3.670,P=0.002;t=4.637,P<0.001;t=5.816,P<0.001);厚角膜组术前,术后1、2、3年Kmax值分别为(54.56±6.27)D、(53.25±6.42)D、(52.32±6.47)D、(51.58±6.70)D,术后各时间点与术前相比差异均有统计学意义(t=2.266,P=0.040;t=3.302,P=0.005;t=3.769,P=0.002);术前薄角膜组Kmax值高于厚角膜组(t=2.714,P=0.011),术后1、2、3年2组间Kmax值差异无统计学意义.术后3年,薄角膜组UCVA、BCVA、TCT与术前相比差异有统计学意义(Z=-2.716,P=0.007;Z=-3.063,P=0.002;t=4.468,P<0.001),厚角膜组UCVA、BCVA、TCT与术前相比差异有统计学意义(t=3.572,P=0.003;Z=-2.956,P=0.003;Z=-3.410,P=0.001).2组眼压、ECD与术前相比差异均无统计学意义.薄、厚角膜组术前组间及术后3年组间UCVA、BCVA、眼压、ECD比较差异均无统计学意义;术前、术后3年组间TCT差异有统计学意义(Z=-4.816,P=0.001;Z=-4.024,P<0.001).结论:CXL可以安全有效地控制薄角膜圆锥角膜患者病情进展,提高视力.

abstractsObjective: To evaluate the effect of ultraviolet A/riboflavin corneal crosslinking (CXL) on keratoconic patients with a corneal thickness less than 400 μm. Methods: In this prospective study, patients with keratoconus were divided into a thin cornea group with a corneal thickness (CT) less than 400 μm and a thick cornea group with a CT more than 400 μm. The patients in the thin and thick cornea groups were treated with a hypotonic or isotonic riboflavin solution before and during CXL. Corneal morphological parameters were evaluated before and after CXL during a 3-year follow-up. The data were analyzed with a repeated measures ANOVA, t test, Wilcoxon rank sum test or Mann-Whitney U test. Results: After surgery, the maximum keratometry (Kmax) of the thin and thick cornea groups underwent a continuous decrease (F= 24.364, P<0.001; F=10.427, P=0.001). In the thin group, the Kmax value was 60.51±6.11 diopters (D) before surgery and significantly decreased to 57.43±6.82 D, 56.13±6.85 D and 54.97±6.66 D at 1, 2 and 3 years after surgery (t=3.670, P=0.002; t=4.637, P<0.001; t=5.816, P<0.001). In the thick group, the Kmax value was 54.56±6.27 D before surgery and significantly decreased to 53.25±6.42 D, 52.32±6.47 D and 51.58±6.70 D at 1, 2 and 3 years after surgery (t=2.266, P=0.040; t=3.302, P=0.005; t=3.769, P=0.002). The Kmax value of the thin cornea group before surgery was higher than that of the thick cornea group (t=2.714, P=0.011). There were no significant differences in Kmax between the two groups at 1 year, 2 years or 3 years. In the thin group, there were significant differences between the preoperative and 3-year postoperative visual acuity (UCVA), best corrected visual acuity (BCVA) and thinnest corneal thickness (TCT) (Z=-2.716, P=0.007; Z=-3.063, P=0.002; t=4.468, P<0.001). In the thick group, there were significant differences between the preoperative and 3-year postoperative UCVA, BCVA and TCT (t=3.572, P=0.003; Z=-2.956, P=0.003; Z=-3.410, P=0.001). In the two groups, there were no significant differences between the preoperative and 3-year postoperative intraocular pressure (IOP) or endothelial cell density (ECD). There were no significant differences in pre- or postoperative UCVA, BCVA, IOP, or ECD between the two groups. There were significiant differences in pre- and postoperative TCT between the two groups (Z=-4.816, P=0.001; Z=-4.024, P<0.001). Conclusion: CXL is an effective and safe way to halt disease progression and improve visual acuity in keratoconic patients with a CT less than 400 μm.