去上皮快速角膜胶原交联术治疗进展期圆锥角膜

目的：研究去上皮快速角膜胶原交联术(CXL)治疗进展期圆锥角膜的疗效。

方法：回顾性研究。收集2020-04/2021-12就诊于宁夏回族自治区人民医院 宁夏眼科医院行去上皮快速CXL的进展期圆锥角膜患者32例43眼。于术前及术后1、3、6mo行裂隙灯、眼压、裸眼视力、矫正视力、角膜内皮镜、眼前节分析仪Pentacam和可视化角膜生物力学Corvis ST检查,记录手术前后角膜情况、裸眼视力(UCVA)、最佳矫正视力(BCVA)、角膜内皮数、角膜最大曲率(Kmax)、角膜厚度最薄点(TCT)、前后表面K1、K2值、矫正眼内压(bIOP)、第一次压平时间(A1T)、第一次压平长度(A1L)、第一次压平速度(A1V)、第二次压平时间(A2T)、第二次压平长度(A2L)、第二次压平速度(A2V))、最大形变幅度(HCDA)、最大形变曲率半径(HCR)、最大压陷时两峰间距(HCPD)、第1次压平时角膜硬度(SP-A1))值。

结果：术前、术后6mo UCVA(LogMAR)(1.06±0.49、0.78±0.39)和BCVA(LogMAR)(0.48±0.34、0.38±0.29)比较均有差异(P<0.05),角膜内皮细胞比较无差异(2917.39±288.38 vs 2959.19±336.27cells/mm²,P=0.477)。手术前后Kmax、TCT、前表面K1、K2值、后表面K1值比较均有差异(P<0.05),且均在术后1mo升高,术后3mo后恢复至术前水平,而后表面K2值比较无差异。手术前后A1T、HCPD、SP-A1比较差异均有统计学意义(P<0.05),A1L、A1V、A2T、A2L、A2V、HCDA、HCR、bIOP比较无差异(P>0.05)

结论：去上皮快速CXL在术后6mo内能够阻止进展期圆锥角膜进展并且具有一定的安全性。     

圆锥角膜行去上皮角膜胶原交联术后角膜微结构的变化

目的：采用共焦显微镜观察进展期圆锥角膜行去上皮角膜胶原交联术后角膜微结构的变化。

方法：选取2016-02/2017-02于我院行上皮角膜胶原交联术治疗的进展期圆锥角膜患者11例15眼,分别于手术前后行共焦显微镜检查,观察角膜微结构变化。

结果：术后早期角膜上皮下神经纤维显著减少或消失; 角膜前基质呈蜂窝状,几乎无典型的角膜基质细胞,术后3mo基质细胞开始出现,术后12mo基质细胞数量几乎恢复到术前水平,但角膜上皮下神经仍稀疏,未达到术前水平; 术后后部角膜基质细胞和内皮细胞大小及形态未受影响。

结论：角膜胶原交联术后角膜微结构发生变化最明显的是上皮下神经纤维和前基质细胞,但随着随诊时间的延长,这种变化呈逐渐减弱趋势。     

角膜基质透镜植入联合角膜胶原交联术治疗圆锥角膜术后角膜上皮重塑

目的：观察飞秒激光辅助下的角膜基质透镜植入联合角膜胶原交联术(SLAK-CXL)治疗进展期圆锥角膜术后角膜上皮重塑情况，探讨角膜上皮重塑规律和影响因素，为进一步屈光矫正提供良好的时机选择。

方法：回顾性、观察性研究。纳入2020-09/2021-10于我院接受SLAK-CXL的圆锥角膜患者28例29眼，记录手术前后视力、眼压(IOP)、屈光度、角膜曲率及角膜上皮厚度(CET)，观察CET变化趋势，并根据透镜厚度和植入深度分析影响CET变化的因素。

结果：与术前比较，纳入患者术后1mo角膜前表面曲率平坦值(K_f)和陡峭值(K_s)均升高(P<0.05)，术后1、2、6mo，1a角膜最薄点厚度(TCT)均升高(P<0.05)。纳入患者术后CET随时间变化而变化，中央区CET变化趋势较明显。与术前相比，术后1、2、6mo，1a旁中央区上方、鼻上方、鼻侧和颞上方CET均降低，中周区上方、颞侧、颞上方CET均降低，外周区鼻上方CET均增加。术后1a，不同植入透镜深度和厚度患者各分区角膜上皮厚度变化量均无差异(P>0.05)。

结论：首次发现SLAK-CXL治疗圆锥角膜术后角膜形态发生变化，CET呈先减少再增加再减少趋势，术后1a中央区、旁中央区CET降低，中周区、外周区CET增加，且角膜上皮重塑程度与术中植入透镜深度和厚度均无关。     

角膜胶原交联术后无菌性角膜炎的临床特征及治疗转归

目的 探讨圆锥角膜患者进行角膜胶原交联(CXL)术后无菌性角膜炎的临床特点、治疗及愈后。方法 回顾性系列病例研究。选择2018年1月至2020年9月河南省立眼科医院屈光手术中心281例(387眼)圆锥角膜患者，其中行CXL术后发生无菌性角膜炎的患者为炎症组(9例11眼),选取同期CXL术后无并发症的圆锥角膜患者为对照组(23例30眼),比较炎症组与对照组患者的年龄、性别、平坦角膜曲率(K₁)、陡峭角膜曲率(K₂)、散光(Astig)及最薄点角膜厚度(TCT)的差异。采用多因素Logistic回归分析无菌性角膜炎发生的影响因素。结果 CXL术后发生无菌性角膜炎患者9例11眼，发生率为2.84%,均发生在去上皮CXL术后。9例11眼均于术后1周内出现无菌性角膜炎，1眼同时累及角膜中央区、旁中央区及周边部，1眼累及旁中央区，其余9眼均位于角膜周边部。炎症组与对照组患者的年龄、性别、K₁、K₂、Astig及TCT差异均无统计学意义(均为P>0.05)。经皮质类固醇激素治疗，预防性使用抗生素滴眼可以取得...     

角膜胶原交联术研究进展

目的角膜胶原交联术(corneal collagen cross linking,CXL)是第一种能有效控制圆锥角膜进展的治疗方法,通过核黄素/紫外光介导的角膜胶原交联,增加角膜的机械强度,阻止了圆锥角膜的进展。经过近年来的研究,CXL的安全性得到了广泛的认可,随着技术方法不断改进,治疗范围也有所扩大。本文就近年来对于CXL原理、适应证、并发症、禁忌证的研究进展进行了综述。     

角膜胶原交联术治疗圆锥角膜的研究进展

角膜胶原交联术(corneal collagen cross-linking,CXL)是一种治疗原发或继发性圆锥角膜、感染性角膜炎及大泡性角膜病变等角膜疾病的新疗法。它利用光化学原理来增加角膜强度,阻止角膜病变进展,现已被广泛应用于临床。目前临床上普遍采用的方法多为经典去上皮角膜交联(dresden protocol),但经典方法耗时较长,可能存在角膜上皮愈合不良、感染等术后并发症。近年来多项研究对经典方式进行了改良,例如核黄素液浸入角膜的多种方式选择,增加紫外光照射能量以缩短照射时间的加速交联以及跨上皮角膜交联等。本文就非经典角膜胶原交联术在治疗圆锥角膜的研究作一综述。     

快速角膜胶原交联术治疗圆锥角膜的安全及有效性研究

目的评价快速角膜胶原交联术(accelerated corneal collagen crosslinking,A-CXL)治疗圆锥角膜的安全性及有效性。方法收集2017年4月至2018年3月在郑州市第二人民医院眼科确诊为进展期圆锥角膜的患者37例(61眼),使用Avedro快速角膜胶原交联系统(30 mW·cm^-2,4 min)进行手术。随访12个月,观察术前及术后最佳矫正视力(best corrected visual acuity,BCVA)、角膜内皮细胞密度(endothelial cell density,ECD)、角膜内皮细胞面积变异系数(coefficient variation of cell size,CV)及六边形角膜内皮细胞比例(percentage of hexagonal cells,Hex)、等效球镜度(spherical equivalent,SE)、角膜前表面最大曲率(maximum keratometry,Kmax)、角膜后表面高度(posterior corneal elevation,PCE)、最薄点角膜厚度(thinnest...     

进展期圆锥角膜去上皮快速角膜交联后早期角膜生物力学的变化

目的 评价去上皮快速角膜交联治疗进展期圆锥角膜的临床疗效及对早期角膜生物力学的影响。方法 前瞻性自身对照研究。对2018年3月到2019年3月进展期圆锥角膜患者18例(29只眼),进行去上皮快速角膜交联治疗。分别在治疗前(基线)和治疗后1、3、6个月采用Corvis ST和Pentacam测量角膜生物力学指标和角膜地形图等。主要观察指标包括第1次压平角膜硬度参数(SP-A1)、角膜最薄点厚度、角膜最大曲率(Kmax)、屈光状态和角膜内皮计数等。对治疗前后的指标进行配对t检验和独立样本t检验。结果 共治疗患者18例(29只眼),平均年龄为(20.33±5.91)岁。术前SP-A1为65.04±15.59,术后1、3、6个月的SP-A1分别为62.44±12.87、69.95±14.89、73.71±15.50,术后1个月SPA1较术前有所下降,但与术前比较差异无统计学意义(P> 0.05);术后6个月较术前明显升高(P <0.05)。68.9%的患者术后6个月时SP-A1改善,与无改善组相比术前Kmax和术前SPA1存在差异(P <0.05)。结论 去上皮快速角膜交联治...     

角膜胶原交联在LASIK术后角膜扩张中的应用

角膜胶原交联(corneal collagen cross-linking,CXL)主要用于治疗圆锥角膜、LASIK术后角膜扩张等角膜扩张性疾病。本文阐述LASIK术后角膜扩张的成因、危险因素,CXL治疗LASIK术后角膜扩张的原理和临床应用。CXL单独或联合其他手术方式治疗LASIK术后角膜扩张,可保留视力、阻止角膜扩张进展、延迟或避免对角膜移植的需要。此外,在有高危因素的患者LASIK术中应用CXL,在短期内可有效预防术后屈光回退的发生及LASIK术后角膜扩张,但远期效果尚需进一步证实。     

屈光性角膜胶原交联术的研究进展

近年发现角膜胶原交联术（CXL）有可能通过优化局部角膜的形态而达到改善屈光状态的效果。此外,也有学者将CXL应用于近视、远视等屈光不正的矫正,取得了一定的疗效。笔者将这些为改善眼部屈光状态而进行的CXL手术（包括单独或联合手术）归类为屈光性CXL。现就近年屈光性CXL的进展作一综述。     

Accelerated versus standard corneal cross linking in the treatment of ectasia post refractive surgery and penetrating keratoplasty: a medium term randomized trial

AIM: To compare the clinical outcomes of the standard corneal cross linking (CXL) and the accelerated CXL in patients with progressive corneal ectasia post refractive surgery and penetrating keratoplasty. METHODS: Totally 120 eyes of 83 patients scheduled to receive either standard CXL (3 mW/cm2 for a period of 30min) or accelerated CXL (18 mW/cm2 for a period of 5min). The main outcomes for comparison were the change in: maximum-K reading (K-max), manifest refractive spherical equivalent (SE), central corneal thickness (CCT), and the best corrected distance visual acuity (CDVA). RESULTS: One hundred and eleven eyes completed the study. The main outcome measurement was the K-max reading. Both group showed significant improvement in the value postoperatively at 6 and 12mo. The mean change in the standard group was 1.21±0.11 D and in the accelerated group was 0.90±0.05 D at the end of 12mo postoperatively, with no statistically significant difference between the 2 groups. Similarly, CDVA improved significantly from their preoperative value in the standard group by 2.98±0.11 letters, and in the accelerated group by 2.20±0.06 letters, with no statistically significant difference between the two groups. Both of the SE, and CCT showed no statistically significant difference at the end of follow up period in each group. CONCLUSION: Both standard CXL and accelerated CXL are safe and effective treatment in halting ectasia after corneal refractive surgery. The accelerated CXL results are comparable to the standard CXL with short time exposure of the cornea to ultraviolet irradiation, leading to reduced operation time, reduced operative ocular discomfort, and corneal haze.     

Long term efficacy and stability of corneal collagen cross linking for post-LASIK ectasia: an average of 80mo follow-up

This study was designed to evaluate efficacy and stability of corneal collagen crosslinking (CXL) in halting the progression of post-laser in situ keratomileusis (LASIK) ectasia and provide long-term follow-up results with an average of 80mo. Patients with post-LASIK ectasia were treated with CXL between December 2007 and January 2012. Main outcome measures were uncorrected distance visual acuities (UDVA) and corrected distance visual acuities (CDVA), minimum and maximum keratometry (K) values, spherical and cylindrical refraction, and corneal thickness. The study evaluated 17 eyes for 13 patients (8 men, 5 women) with mean age of 31y (range 23 to 39) and mean follow-up of 80.7±15 (range 57 to 102)mo. UDVA and CDVA improved from logMAR 0.53±0.36 (20/63) to 0.49±0.4 (20/50) (P=0.43) and from 0.18±0.17 (20/28) to 0.16±0.16 (20/27) (P=0.55) respectively. In 15 eyes UDVA and in 13 eyes CDVA either remained stable or improved ≥1 Snellen lines (88.2%) and (76.5%) respectively. Although statistically insignificant, spherical and cylindrical refraction decreased post-CXL from -1.26±2.87 to -0.38±2.32 diopters (D) (P=0.054) and from -3.80±2.47 to -3.04±2.18 D (P=0.13) respectively. Kmax significantly decreased from 44.23±3.76 to 42.85±3.08 D (P=0.013) and Kmin decreased from 41.07±3.61 to 40.00±2.65 D (P=0.057). Corneal thickness decreased from 470±42 to 460±41 μm, but was statistically non-significant (P=0.063). Therefore, CXL is effective in halting and partially reversing the progression of post-LASIK ectasia on the long-term (mean follow-up of more than 80mo), thus highlighting the stability and maintained effect of CXL for such cases.     

Comparison of corneal biological parameters between transepithelial and epithelium-off corneal cross-linking in keratoconus

AIM: To evaluate the differences in corneal biological parameters between transepithelial and epithelium-off corneal cross-linking in keratoconus. METHODS: In our prospective clinical trial, 40 patients (60 eyes) with progressive keratoconus were randomized to undergo corneal cross-linking with transepithelial (TE group, n=30) or epithelium-off (EO group, n=30) keratoconus. Examinations comprised topography, corneal biomechanical analysis and specular microscopy at 6mo postoperatively. RESULTS: The keratometer values were not significantly different between the TE and EO corneal cross-linked groups in different periods (each P>0.05). The corneal thickness of the EO group was greater than that of the TE group at 1wk after the operation (each P<0.05). Regarding corneal biomechanical responses, the EO group showed a longer second applanation length than TE group (P=0.003). Regarding the corneal endothelial function, standard deviation of the endothelial cell size, and coefficient of variation in the cell area, the values of EO group were larger than those of TE group at 1wk (P=0.011, 0.026), and the percentage of hexagonal cells in EO group was lower than that in TE group at 1 and 6mo (P=0.018, 0.019). CONCLUSION: Epithelium-off corneal cross-linking may strengthen corneal biomechanics better than TE procedure can. However, the TE procedure with a lower ultraviolet-A irradiation intensity would be safer for corneal endothelial function.     

Collagen cross linking: Current perspectives

Keratoconus is a common ectatic disorder occurring in more than 1 in 1,000 individuals. The condition typically starts in adolescence and early adulthood. It is a disease with an uncertain cause and its progression is unpredictable, but in extreme cases, vision deteriorates and can require corneal transplant surgery. Corneal collagen cross-linking (CCL) with riboflavin (C3R) is a recent treatment option that can enhance the rigidity of the cornea and prevent disease progression. Since its inception, the procedure has evolved with newer instrumentation, surgical techniques, and is also now performed for expanded indications other than keratoconus. With increasing experience, newer guidelines regarding optimization of patient selection, the spectrum of complications and their management, and combination procedures are being described. This article in conjunction with the others in this issue, will try and explore the uses of collagen cross-linking (CXL) in its current form.     

角膜胶原蛋白交联的研究进展

角膜是眼球重要的结构之一,呈透明状态,约占纤维膜的前1/6。它所含的胶原蛋白排列规则,可以让光线通过,正是因为胶原蛋白特殊的排列方式,才使角膜拥有良好的透明状态。由此可见胶原蛋白对角膜的重要作用,现在本文就胶原蛋白在角膜中的分布、生理功能、角膜交联术后的变化和临床运用、安全性综述如下。