准分子激光原位角膜磨镶术联合快速角膜交联术矫正薄角膜近视合并散光的早期疗效

Early clinical outcomes of laser in situ keratomileusis concurrent with accelerated corneal collagen crosslinking for myopia and astigmatism with thin cornea

背景准分子激光原位角膜磨镶术（LASIK）术后发生的医源性角膜扩张严重威胁患者的术后视力和角膜生物力学强度，LASIK联合角膜交联术（LASIK—CXL）有望提高手术的安全性，降低术后角膜扩张的风险，但其手术效果及安全性有待验证。目的探讨LASIK—CXL矫正薄角膜近视合并散光眼的临床应用价值及其安全性。方法采用前瞻性队列研究设计，纳入2014年1月至2015年1月在北京同仁医院眼科拟接受LASIK的薄角膜近视合并散光患者64例128眼，患者分为LASIK组（37例74眼）和LASIK—CXL组（27例54眼），2个组基线特征匹配。所有术眼均采用飞秒激光制瓣，并用准分子激光进行角膜消融，LASIK—CXL组患者在LASIK术后立即用质量分数0．1％核黄素滴至角膜基质床持续90s，平衡盐溶液（BSS）行瓣下冲洗后用紫外线交联加固仪照射进行角膜交联。2个组患者分别于术后1周及1、3、6个月进行随访，对2个组术眼视力、屈光度、角膜地形图参数、眼前节OCT（AS—OCT）检查结果及角膜生物力学参数进行比较。结果LASIK组和LASIK—CXL组术前等效球镜度（sE）分别为（-6．49±2．41）D和（-6．97±2．41）D，术后6个月时分别降低至（-0．68±0．88）D和（-0，75±0．94）D；2个组术前裸眼视力（UDVA）（LogMAR）分别为1．18±0．28和1．05±0．38，术后6个月时分别提高至-0．06±0．09和-0．03±0．18；术前AveK值分别为（44．37±1．46）D和（44．47±1．50）D，术后6个月时分别减少至（39．30±2．06）D和（38．66±1．80）D；术前表面规则指数（SRI）分别为0．25±0．21和0．24±0．22，术后6个月时分别增加为0．29±0．24和0．28±0．24，术前表面不对称指数（SAI）分别为0．36±0．16和0．39±0．15，术后6个月时分别增至0．57±0．31和0．75±0．37，且LASIK—CXL组术后SAI值明显大于LASIK组，差异有统计学意义（F=10．22，P=0．002）。LASIK组和LASIK—CXL组术前角膜阻力因子（CRF）值分别为（8．44±1．44）mmHg（1mmHg=0．133kPa）和（8．63±1．35）mmHg，术后6个月分别下降至（5．74±1．31）mmHg和（6．25±1．24）mmHg，且LASIK-CXL组CRF值明显高于LASIK组，差异有统计学意义（F=8．650，P=0．004）；LASIK组和LASIK—CXL组术前角膜滞后量（CH）分别为（8．78±1．51）mmHg和（8．69±1．62）mmHg，术后6个月分别降至（7．23±1．08）mmHg和（6．50±1．32）mmHg，LASIK—CXL组术后CH值明显低于LASIK组，差异有统计学意义（F=5．860，P=0．017）。AS—OCT检查显示术后1个月LASIK—CXL组角膜基质出现高密度反光带者45眼，占81．82％，而LASIK组术眼未出现角膜基质高密度反光带。结论LASIK。CXL矫正薄角膜近视合并散光眼是有效的和安全的，其改善术眼术后视力的效果与LASIK接近，但在增加角膜硬度方面明显优于LASIK手术。

Background Keratectasia after laser in situ keratomileusis （LASIK） is a rare but severe complication,which threatens the visual acuity and corneal strength. Corneal collagen crosslinking （CXL） is a new therapy that increases the security and decreases the risk of complication. However, the effectiveness and safety ofLASIK-CXL is still need to be concerned. Objective This study was to evaluate the safety of LASIK-CXL for myopia and astigmatism with thin cornea. Methods A prospective cohort study was designed. A total of 128 eyes of 64 patients with thin corneal and myopic astigmatism enrolled in Beijing Tongren Eye Center from January 2014 to January 2015. The patients were assigned to LASIK group （74 eyes of 37 patients） and LASIK-CXL group （54 eyes of 27 patients）. Refractive surgery was performed by Visumax femtosecond lasrer and VISX S4 excimer laser. Eyes of LASIK-CXL group applied accelerated CXL immediately after LASIK. The follow-up was 6 months. Manifest refraction, uncorrected （UDVA） and corrected distance visual acuity （ CDVA）, average keratometry values （ AveK）, anterior segment OCT （AS-OCT）, corneal hysteresis （CH） and corneal resistance factor （CRF） were examined before and after operation. This research passed through Ethics Committee of Beijing Tongren Hospital. Results The spherical equivalent （SE） of the LASIK group and LASIK-CXL group were （-6.49 ±2.41 ）D and （-6.97 ± 2. 41）D before operation and decreased to （ -0. 68±0. 88） D and （ -0. 75±0. 94） D 6 months after operation. The UDVA （LogMAR） was 1.18±0. 28 and 1.05±0.38 before operation and elevated to -0.06±0.09 and -0.03±. 186 months after operation in the LASIK group and LASIK-CXL group. The preoperative AveK values were （44. 37±1.46）D and （44.47±.50）D in the LASIK group and LASIK-CXL group and reduced to postoperative （39.30±2.06）D and （38.66±1.80）D. The preoperative SRI of LASIK group and LASIK-CXL group were 0.25±0. 21 and 0. 24±.22,which increased to 0. 29±0. 24 and 0. 28±0. 24. The SAI values were 0. 36±0. 16 and O. 39±0. 15 before operation,which increased to 0.57±.31 and 0.75 ±0. 376 months after operation, and the SAI value of the LASIK- CXL group was significantly higher than that of LASIK （ F= 10. 220 ,P=0. 002）. CRF values of LASIK and LASIK- CXL were （ 8.44±1.44 ） mmHg and （ 8.63 ± 1.35 ） mmHg in preoperation, which decreased to （ 5.74 ± 1.31 ） mmHg and （6.25 ± 1.24）mmHg in postoperation. The result of LASIK-CXL was higher than that of LASIK （F= 8. 650,P = 0. 040）. CH values were 8.78±0.51 and 8.69±1.62 in preoperation,which decreased to （7.23±1.08） mmHg and （6.50± 1.32） mmHg. The value of LASIK-CXL was lower than that of LASIK （ F = 5. 860, P = 0. 017 ）. The mean depth of demarcation line was （228.45±8.24） μm （ range 165 to 310 μm） on OCT,which was presented in 45 eyes （81.82%） at 1 month in postoperation. Conclusions Accelerated CXL with FS-LASIK is effective and safe in improving visual acuity in myopic astigmatism patients with thin cornea,which also can increase the rigidity of the cornea.