飞秒激光联合紫外光核黄素角膜交联术治疗圆锥角膜的一年效果

One year therapeutic effect of riboflavin-ultraviolet corneal collagen crosslinking using femtosecond laser for keratoconus

目的评估飞秒激光联合紫外光核黄素角膜交联术(femtosecond laser-assisted intrastromal crosslinking,F-CXL)治疗圆锥角膜的有效性。设计前瞻性病例系列。研究对象2015年10月至2016年5月北京同仁医院眼科进展性圆锥角膜患者22例(30眼)。方法所有患者采用在表面麻醉下行飞秒激光联合紫外光核黄素角膜交联术F-CXL进行治疗。术前,术后1天,1周,1、3、6、12个月检查视力、屈光度、角膜地形图、角膜共聚焦显微镜、角膜内皮镜及角膜生物力学。主要指标最佳矫正视力(best corrected visual acuity,BCVA)、最薄角膜厚度(thinnest corneal thickness,TCT)、角膜陡峭子午线屈光力(corneal steep K-reading,Ks)、角膜平坦子午线屈光力(corneal flat K-reading,Kf)以及角膜平均屈光力(average K-reading,Avek)、角膜中央厚度(corneal central thickness,CCT)、角膜滞后量(corneal hysteresis,CH)、角膜阻力因素(corneal resistence factor,CRF)、角膜交联线以及角膜共聚焦显微镜所见。结果所有患者未发生术中、术后严重不良反应及并发症。术后1天出现轻度刺激症状,均于术后3天自行缓解或消失。术后12个月角膜Ks、Kf以及Avek均未见显著增加,CCT无显著降低,CH及CRF均未见显著下降(P均>0.05),并且交联效果在术后3~6个月最佳,随后逐渐下降。术前K值>53.08 D的圆锥角膜患者术后Ks值显著提高,但相关分析并未显示年龄、基线BCVA、基线TCT与术后柱镜、Ks、Avek以及CCT有关。术后1周18眼(60%)中可观察到交联线,随后交联线逐渐变清晰和致密,术后3个月交联线深度约(320.31±51.32)μm。角膜共聚焦显微镜显示,在术后1个月后在角膜基质内可以观察到活跃的角膜细胞核以及新生成的、结构紧密的胶原纤维。在随访过程中均未观察到显著的角膜内皮数量损失。结论飞秒激光联合紫外光核黄素角膜交联法能有效阻止圆锥角膜进展,术后角膜生物力学无明显下降,安全性较好,能够为后续开展联合囊袋内透镜植入术提供安全依据。

Objective To evaluate the safety and effect of femtosecond-assisted intrastromal corneal cross-linking(F-CXL)for keratoconus.Design Prospective case series.Participants Twenty two patients(30 eyes)diagnosed as progressive keratoconus accepted F-CXL in Tongren Eye Center from Oct.2015 to May.2016.Methods All eyes were scheduled to receive the riboflavin-ultraviolet corneal collagen crosslinking using a femtosecond laser pocket under surface anesthesia objective measurements,including corneal topography,corneal pachymetry,demarcation line,corneal biomechanical property and endothelial cell count were evaluated preoperatively and at 1 day,1 week,1 month,3 months,6 months and 12 months postoperatively.Main Outcome Measures Best corrected visual acuity(BCVA),thinnest corneal thickness(TCT),corneal steep K-reading(Ks)、corneal flat K-reading(Kf),average K-reading(Avek),corneal central thickness(CCT)、corneal hysteresis(CH),corneal resistence factor(CRF),corneal endothelial cell count,demarcation line and images by confocal microscope.Results No serious complications happened during or after the surgery.However,some eyes experienced mild or moderate discomforts 1 day after surgery which were well relieved after 3 days.During 12-month follow-up,there was no significant increase in topographic parameters including Ks,Kf,Avek and reductions in CCT,CH,CRF.Desides,F-CXL performed the best from 3 months to 6 months postoperatively and then weakened gradually.Spearman analysis showed the preoperative Ks greater than 53.08 D was associated with more improvement in Ks but age,baseline BCVA and baseline TCT were found unrelated to the amount of change in Ks,Avek,Cyl and CCT.Corneal stromal demarcation line could be identified from 1 week in 18 eyes(60%)and then got more clear and intact,the mean depth of which was(302.56±31.02)μm at 3 months.In addition,corneal confocal microscopy revealed that activated keratocytes and newly-formed,compact collagen fibers could be observed after 1 month.During the follow-up,no significant reduction in corneal endothelium cell count proved the safety of this technique.Conclusion F-CXL is an effective and safe method to halt the advancement of progressive KC which is a solid preliminary basis of the combined surgery,despite further studies and close monitoring required.