角膜前基质针刺术治疗角膜上皮细胞功能障碍的临床疗效

目的：探讨角膜前基质针刺术(ASP)治疗角膜上皮细胞功能障碍(CED)的临床疗效。

方法：选取2015-09/12于华中科技大学同济医学院附属协和医院眼科行ASP治疗的CED患者16例16眼,分别于术前、术后1、3mo观察裸眼视力、眼表疾病指数评分(OSDI)、角膜荧光染色、角膜上皮厚度、全角膜厚度、角膜上皮下树突状细胞密度、角膜内皮细胞密度、角膜上皮下神经丛密度。

结果：术后1mo,本组患者裸眼视力、上皮下神经丛密度均较术前明显改善,OSDI评分、角膜上皮厚度、全角膜厚度、角膜上皮下树突状细胞密度均较术前明显降低(P<0.05),而角膜内皮细胞密度较术前无明显变化(P>0.05)。术后3mo,裸眼视力、OSDI评分、角膜上皮厚度、全角膜厚度、角膜内皮细胞密度与术后1mo无明显差异(P>0.05),但角膜上皮下树突状细胞密度明显下降,上皮下神经丛密度明显增加(P<0.05)。

结论：ASP可以有效治疗CED及其诱发的炎症,并可修复其导致的角膜上皮下神经丛缺损。     

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。     

不同经上皮角膜胶原交联方法治疗进展期圆锥角膜的早期疗效观察

目的：观察比较不同经上皮角膜胶原交联方法(transepithelial corneal collagen cross-linking,TE-CXL)治疗进展期圆锥角膜的早期疗效。

方法：回顾性研究。将24例34眼进展期圆锥角膜分为三组,低渗CXL组10眼接受低渗胶原交联治疗,I-CXL 5min组14眼接受离子导入5min胶原交联治疗,I-CXL 10min组10眼接受离子导入10min胶原交联治疗。治疗前,治疗后1wk,1、3、6mo观察视力、Pentacam眼前节分析仪、角膜激光共焦显微镜、光学相关断层扫描结果变化。

结果：术后6mo,I-CXL 10min组CDVA(矫正远视力,LogMAR)提高-0.21±0.23(t=2.735,P=0.026); 最大角膜屈光力(K_max)降低2.32±5.21D,但差异无统计学意义(t=1.40,P=0.193),低渗CXL组与I-CXL 5min组的UDVA、CDVA、Kmax稳定,差异均无统计学意义(P>0.05)。术后1wk时,分界线平均深度在各组分别为：低渗CXL组152.7±42.9μm,I-CXL 5min组213.6±42.3μm,I-CXL 10min组237.0±46.4μm,组间比较,差异有统计学意义(F=7.111,P=0.006)。术后基质细胞的凋亡-活化-再生现象在I-CXL 10min组最明显。三组角膜最薄点厚度、角膜内皮细胞密度与术前比较,差异无统计学意义(P>0.05)。

结论：三种经上皮CXL短期观察均能安全有效控制圆锥角膜病情的发展,其中离子导入10min胶原交联方法组织反应更显著。     

共焦显微镜观察慢性角膜水肿患者角膜各层形态特点

目的：应用活体共焦显微镜(IVCM)观察慢性角膜水肿患者角膜各层形态特点。

方法：使用IVCM观察不同病因的慢性角膜水肿的患者21例21眼,并与5例拟行白内障手术患者的正常角膜进行对照。

结果：IVCM观察到所有慢性角膜水肿患者角膜上皮层均可见大泡,表现为黑色、圆形、边缘清晰。18眼(86%)上皮细胞出现高反射的无细胞结构的片状区域和瘢痕。12眼(57%)患者中央区角膜上皮下未发现神经纤维,9眼(43%)患者中央区角膜上皮下神经平均密度显著降低。所有患者Bowman膜(BZ)表现为明显的异常,除了瘢痕外,BZ呈分支的、细的、黑线状。13眼(62%)患者前基质表现为细颗粒或粗颗粒,且反光不同。所有患者角膜基质细胞密度降低。所有患者角膜内皮表现为正常六边形结构消失,细胞边界不清。对照组角膜正常未见上述改变。

结论：IVCM可以用来观察慢性角膜水肿角膜各层微观结构上的变化,包括上皮瘢痕形成、上皮下神经纤维及基质细胞的减少。随着角膜内皮移植术的日益普及,本研究支持IVCM在定量评估术前、术后角膜水肿的作用。     

非角膜地形图引导PRK联合角膜胶原交联术治疗圆锥角膜

目的：评估非角膜地形图引导圆锥角膜患者行光折变角膜切除术(PRK)和角膜胶原交联术(CXL)的视力、屈光度和临床疗效。

方法：术后1mo, 3mo, 6mo and 12mo对34例患者未矫正视力(UDVA)和矫正距离视力(CDVA),平、陡角膜测量读数以及并发症进行评估。

结果：共34例患者平均年龄为23.3±4.0岁。UDVA和CDVA显著提高,且术后1a恢复平稳。通过超过1a的定期随访,T检验显示术前术后值有显著不同(P<0.05)包括视力,球面和柱面变化。Fourier术后图像分析显示轴向位移垂直于术前轴。

结论：非角膜地形图引导PRK联合CXL对于治疗圆锥角膜是一种安全有效的手术选择,能够提高UDVA,CDVA和屈光状态。术后3mo达到稳定状态,与非角膜地形图引导PRK相比,地形图引导的唯一优势可能是通过Fourier术后分析,在某些患者中,球镜和柱镜轴位漂移。     

角膜基质环植入术治疗圆锥角膜的临床疗效

目的：评估角膜基质环植入术治疗圆锥角膜的临床疗效。

方法：这一回顾性对照干预性研究对56例87眼圆锥角膜患者进行手术后随访。所有患者完善眼科检查,评估视力。15眼使用飞秒激光制备角膜隧道。72眼使用机械的方法制备角膜隧道。

结果：所有患者术前裸眼视力1.38±0.37。术后4mo裸眼视力达到0.58±0.32。术后16mo达到0.48±0.30。

结论：角膜基质环植入术是治疗圆锥角膜的有效方法。有效的干预与理想的术后视力相关。飞秒激光角膜隧道制备和机械方法一样安全。     

共聚焦显微镜观察圆锥角膜行角膜胶原交联术后早期组织形态学变化

目的探讨进展期圆锥角膜行角膜胶原交联术后早期共聚焦显微镜下的组织形态学改变。方法回顾性病例系列研究。应用共聚焦显微镜观察2017年9月至2019年3月于解放军总医院眼科行角膜胶原交联术的进展期圆锥角膜患者23例(32只眼), 其中男性15例(24只眼), 女性8例(8只眼);年龄(26±10)岁。所有患者于术前和术后1周、1个月、3个月应用共聚焦显微镜观察角膜组织结构改变、定量记录角膜上皮下神经纤维、基质细胞、内皮细胞密度和基质结构改变的深度并进行对比分析。不同时间的总体差异比较采用重复测量资料的方差分析或Friedman检验, 不同时间的差异的多重比较采用LSD-t检验或Bonferroni校正。结果角膜胶原交联术后1周, 角膜上皮细胞处于修复期, 表现为上皮基底细胞核增大、反射增强, 上皮下可见活化细胞, 浅基质肿胀呈海绵状, 深基质肿胀呈不均匀斑块状或条索状, 反射强。术后1个月, 上皮基底细胞恢复, 上皮下神经开始生长, 浅基质持续呈海绵状肿胀, 反射进一步增强, 深基质肿胀呈更粗大的斑块或条索样结构并持续至术后3个月。术前与术后3个月内, 角膜上皮下神经纤维密度差异有统计学意义(F=233.30, P<0.001), 术后1周、1个月、3个月角膜上皮下神经纤维密度分别为(0.51±0.31)、(3.65±2.21)、(8.50±4.02)mm/mm², 与术前的(14.60±2.57)mm/mm²相比均明显降低(均P<0.05);不同时间点角膜前部基质细胞密度比较, 差异有统计学意义(χ²=92.48, P<0.001), 术后1周、1个月、3个月角膜前部基质细胞密度分别为2.00(1.00, 5.75)、2.50(1.00, 5.75)、79.00(64.25, 94.00)个/mm², 与术前的347.00(345.00, 395.75)个/mm²相比均明显降低(均P<0.05)。术后3个月内角膜基质结构改变的深度范围为(400.56±86.12)μm:术后1周、1个月、3个月分别为(402.13±89.20)、(399.88±85.92)、(399.69±85.94)μm, 差异无统计学意义(F=0.80, P=0.455)。术前和术后不同时间角膜后部基质细胞密度[术前为(260.6±33.2)个/mm², 术后1周、1个月、3个月分别为(264.4±44.5)、(263.9±37.6)、(266.3±40.2)个/mm²]和内皮细胞密度[术前为(2 707.1±152.6)个/mm², 术后1周、1个月、3个月分别为(2 704.2±148.5)、(2 705.6±152.6)、(2 704.5±150.1)个/mm²]比较, 差异均无统计学意义(F=1.38, 1.01;P=0.259, 0.351)。结论圆锥角膜行角膜胶原交联术后早期, 共聚焦显微镜下可见角膜上皮和上皮下神经的改变呈现损伤修复的过程;角膜浅基质呈均匀的蜂窝状肿胀, 深基质呈不均匀斑块状或条索状肿胀;术后早期角膜基质结构改变的深度相对稳定。     

共聚焦显微镜观察圆锥角膜行角膜胶原交联术后早期组织形态学变化

目的探讨进展期圆锥角膜行角膜胶原交联术后早期共聚焦显微镜下的组织形态学改变。方法回顾性病例系列研究。应用共聚焦显微镜观察2017年9月至2019年3月于解放军总医院眼科行角膜胶原交联术的进展期圆锥角膜患者23例(32只眼), 其中男性15例(24只眼), 女性8例(8只眼);年龄(26±10)岁。所有患者于术前和术后1周、1个月、3个月应用共聚焦显微镜观察角膜组织结构改变、定量记录角膜上皮下神经纤维、基质细胞、内皮细胞密度和基质结构改变的深度并进行对比分析。不同时间的总体差异比较采用重复测量资料的方差分析或Friedman检验, 不同时间的差异的多重比较采用LSD-t检验或Bonferroni校正。结果角膜胶原交联术后1周, 角膜上皮细胞处于修复期, 表现为上皮基底细胞核增大、反射增强, 上皮下可见活化细胞, 浅基质肿胀呈海绵状, 深基质肿胀呈不均匀斑块状或条索状, 反射强。术后1个月, 上皮基底细胞恢复, 上皮下神经开始生长, 浅基质持续呈海绵状肿胀, 反射进一步增强, 深基质肿胀呈更粗大的斑块或条索样结构并持续至术后3个月。术前与术后3个月内, 角膜上皮下神经纤维密度差异有统计学意义(F=233.30, P<0.001), 术后1周、1个月、3个月角膜上皮下神经纤维密度分别为(0.51±0.31)、(3.65±2.21)、(8.50±4.02)mm/mm², 与术前的(14.60±2.57)mm/mm²相比均明显降低(均P<0.05);不同时间点角膜前部基质细胞密度比较, 差异有统计学意义(χ²=92.48, P<0.001), 术后1周、1个月、3个月角膜前部基质细胞密度分别为2.00(1.00, 5.75)、2.50(1.00, 5.75)、79.00(64.25, 94.00)个/mm², 与术前的347.00(345.00, 395.75)个/mm²相比均明显降低(均P<0.05)。术后3个月内角膜基质结构改变的深度范围为(400.56±86.12)μm:术后1周、1个月、3个月分别为(402.13±89.20)、(399.88±85.92)、(399.69±85.94)μm, 差异无统计学意义(F=0.80, P=0.455)。术前和术后不同时间角膜后部基质细胞密度[术前为(260.6±33.2)个/mm², 术后1周、1个月、3个月分别为(264.4±44.5)、(263.9±37.6)、(266.3±40.2)个/mm²]和内皮细胞密度[术前为(2 707.1±152.6)个/mm², 术后1周、1个月、3个月分别为(2 704.2±148.5)、(2 705.6±152.6)、(2 704.5±150.1)个/mm²]比较, 差异均无统计学意义(F=1.38, 1.01;P=0.259, 0.351)。结论圆锥角膜行角膜胶原交联术后早期, 共聚焦显微镜下可见角膜上皮和上皮下神经的改变呈现损伤修复的过程;角膜浅基质呈均匀的蜂窝状肿胀, 深基质呈不均匀斑块状或条索状肿胀;术后早期角膜基质结构改变的深度相对稳定。     

共焦显微镜在复发性角膜上皮糜烂综合征治疗中应用

目的：探讨共焦显微镜在指导长期配戴绷带式角膜接触镜治疗复发性角膜上皮糜烂综合征中的价值。

方法：随机选取2014-03/09就诊于我院36例36眼复发性角膜上皮糜烂综合征患者配戴绷带式角膜接触镜,观察戴镜前,戴镜后2、4、8、12wk眼部疼痛和刺激症状、角膜上皮愈合情况、共焦显微镜图像及不良反应情况。

结果：患者在配戴绷带式角膜接触镜后30min眼部的疼痛与刺激症状均得到不同程度缓解,完全缓解者26眼(72%),明显缓解者10眼(28%); 角膜上皮的平均愈合时间5.68±0.73d; 2、4、8、12wk时共焦显微镜下基底细胞形态、排列,上皮下神经纤维密度、走形日渐趋于正常; 临近角膜上皮基底细胞的前基质层炎细胞逐渐消退。观察期间未发现1例与配戴接触镜有关的并发症。

结论：共焦显微镜指导下绷带式角膜接触镜治疗复发性角膜上皮糜烂综合征可以避免过早摘镜,使基底膜与前弹力层紧密粘连,减少复发,是一种简便、安全、有效方法。     

准分子激光双面式切削原位角膜磨镶术治疗近视的实验研究

目的:探讨准分子激光双面式切削原位角膜磨镶术(both-sided LASIK,BSL)的角膜创口愈合过程。方法:24只新西兰大白兔右眼按-3.00D行LASIK,左眼角膜瓣上基质和基质床上分别按-1.50D行BSL,分别于术后1,7d;1,3mo随机选取6只动物,行裂隙灯、活体共焦显微镜、组织病理学及透射电镜检查。结果:BSL术后角膜中央区透明,没有雾状浑浊(haze),早期角膜瓣边缘上皮增厚,变厚的上皮下角膜基质轻度不规则,随时间逐渐趋于正常。术后各时间均未见炎性细胞浸润。活体共焦显微镜下:BSL术后角膜瓣层间出现散在高反光颗粒,早期部分基质细胞激活,BSL组与LASIK组比较上皮基底细胞、创面后基质细胞、反光颗粒、激活细胞、神经纤维及内皮细胞数量与术后同时期比较均无显著性差异(P>0.05)。透射电镜下:BSL术后早期上皮细胞轻微变性,少量纤维细胞核染色质边集,角膜瓣边缘局部胶原排列稍紊乱。1mo时基质胶原纤维排列整齐,直径大小一致。角膜各细胞的超微结构改变程度、角膜愈合的组织病理学变化与普通LASIK术后相似。结论:准分子激光双面式切削原位角膜磨镶术后角膜生物组织反应轻微,角膜愈合反应程度与普通LASIK术后相似,同时为最大限度的保留角膜基质床的剩余厚度创造了条件,是治疗近视的一种好的选择。     

In vivo corneal confocal microscopic analysis in patients with keratoconus

AIM:To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects.METHODS: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slit-lamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated.RESULTS: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub-basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817±306 cells/mm² vs 4802±508 cells/mm², P<0.001), anterior stromal keratocyte density (800±111 cells/mm² vs 555±115 cells/mm², P<0.001), posterior stromal keratocyte density (333±34 cells/mm² vs 270±47 cells/mm², P<0.001), endothelial cell density (2875±223 cells/mm² vs 2686±265 cells/mm², P<0.001), sub-basal nerve fiber density (31.2±8.4 nerves/mm² vs 18.1±9.2 nerves/mm², P<0.001), sub-basal nerve fiber length (21.4±3.4 mm/mm² vs 16.1±5.1 mm/mm², P<0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 - third quartile 68.7) nerve branches/mm² vs median 25.0 (first quartile 6.2 - third quartile 45.3) nerve branches/mm², P<0.001) were observed in patients with keratoconus.CONCLUSION: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non-invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus.     

The significance of Vogt's striae in keratoconus as evaluated by in vivo confocal microscopy

Background: To evaluate the association of the presence, extent and width of Vogt's striae with other microstructural corneal alterations in keratoconus using in vivo confocal microscopy (IVCM). Methods: Sixty‐eight keratoconic corneas of 68 patients were evaluated with slit‐lamp examination (SLE), corneal topography and IVCM. For each eye, the presence, extent and width of alternating light and dark bands (Vogt's striae) observed using IVCM was recorded together with keratocyte and endothelial cell densities, stromal nerve thickness, subbasal nerve density and thickness. The refractive status and the mean and steepest corneal curvatures were noted. Results: Vogt's striae were present in 43 (63.2%) eyes on SLE and dark bands were present in 53 (77.9%) eyes on IVCM. Compared with patients without dark bands, patients with dark bands had significantly higher refractive errors in spherical equivalents (SE; ?8.15 ± 3.70 vs. ?5.18 ± 2.46 diopters [D], P = 0.007), higher astigmatic errors (?5.88 ± 2.69 vs. ?4.10 ± 1.84 D, P = 0.027), higher steepest corneal curvatures (54.33 ± 4.38 vs. 51.23 ± 3.72 D, P = 0.018), lower anterior stromal keratocyte densities (1106 ± 172 vs. 1222 ± 171 cells/mm², P = 0.022) and lower nerve fibre densities (18.74 ± 6.54 vs. 22.66 ± 6.47 nerves/mm², P = 0.054). Compared with patients in whom dark bands were confined to the posterior stroma, patients with dark bands extending into the anterior stroma had significantly higher refractive errors in SE (?11.17 ± 2.25 vs. ?6.34 ± 3.48 D, P < 0.001), higher astigmatic errors (?7.44 ± 2.56 vs. ?4.69 ± 2.22 D, P = 0.006) and wider bands (6.0 ± 2.1 vs. 9.6 ± 3.1 µm, P < 0.001). Conclusions: Vogt's striae appear to be more prevalent in keratoconic corneas than can be appreciated clinically. The presence of Vogt's striae may be associated with corneal topographic and microstructural changes.     

Mapping the corneal sub-basal nerve plexus in keratoconus by in vivo laser scanning confocal microscopy

PURPOSE: To produce a two-dimensional reconstruction map of the living corneal sub-basal nerve plexus in keratoconus with in vivo confocal microscopy. METHODS: Four eyes of four subjects with keratoconus were examined by slit lamp biomicroscopy, Orbscan II slit-scanning elevation topography (Bausch & Lomb Surgical, Rochester, NY), and laser scanning in vivo confocal microscopy with the Heidelberg Retina Tomograph II, Rostock Corneal Module (Heidelberg Engineering, Heidelberg, Germany). Subjects were asked to fixate on targets arranged in a grid to enable in vivo confocal microscopy of the cornea in a wide range of positions. RESULTS: A mean of 402 +/- 57 images were obtained for each cornea, to create confluent montages. The mean dimensions of the corneal areas mapped were 6.60 +/- 0.70 mm horizontally and 5.91 +/- 0.72 mm vertically. All corneas exhibited abnormal sub-basal nerve architecture compared with patterns previously observed in normal corneas. At the apex of the cone, a tortuous network of nerve fiber bundles was noted, many of which formed closed loops. At the topographic base of the cone, nerve fiber bundles appeared to follow the contour of the base, with many of the bundles running concentrically in this region. Central sub-basal nerve density was significantly lower in keratoconus corneas (10,478 +/- 2,188 microm/mm2) compared with normal corneas (21,668 +/- 1,411 microm/mm2; Mann-Whitney; P < 0.01). CONCLUSIONS: This is the first study to elucidate the overall distribution of sub-basal nerves in the living central to midperipheral human cornea in keratoconus, using laser scanning in vivo confocal microscopy.     

运用双通道视觉质量分析系统评估角膜交联手术后的客观视觉质量

目的：：采用双通道视觉质量分析系统评估圆锥角膜患者角膜交联手术前后的客观视觉质量。方法：收集2015-01/07患有进展期圆锥角膜而进行紫外光-核黄素角膜交联手术的患者病例资料。利用双通道系统比较手术前和手术后6 mo 患者的客观散射指数( OSI)、对比度视力( VA)、调制传递函数截止频率( MTF cut off)和斯特列尔比( SR)。结果：共收录患者13例16眼。术后6 mo裸眼视力、最佳矫治视力、屈光度、Sim-k平均值与术前相比差异无统计学意义(P>0.05);眼前节分析仪非侵袭平均泪膜破裂时间( NI Avg-BUT)比术前相比有明显下降,差异有统计学意义(P<0.05)。双通道视觉质量分析系统术后6mo时的MTF cut off、Strehl Ratio、OSI与术前相比差异无统计学意义( P>0.05);泪膜分析平均 OSI ( tear film analysis mean OSI)比术前明显升高,差异有统计学意义(P<0.05)。结论：角膜交联手术没有使患者的术后视觉质量受到影响,但对术后6 mo的泪膜稳定性有轻度影响,长期结果有待进一步观察。     

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.     

In vivo confocal laser-scanning microscopy to characterize wound repair in rabbit corneas after collagen cross-linking

Background: Collagen cross‐linking using the photosensitizer riboflavin combined with ultraviolet A light was developed to stiffen the cornea by increasing its mechanical and biochemical stability. Investigation of post‐treatment events, such as wound healing, is important to evaluate possible risks and to optimize treatment protocols. This in vivo confocal laser‐scanning microscopy study in rabbits was conducted to provide a quantitative and qualitative analysis of corneal wound repair over 16 weeks following collagen cross‐linking. Methods: Six New Zealand White rabbits underwent riboflavin/ultraviolet A cross‐linking. In vivo confocal laser‐scanning microscopy using a Heidelberg Retina Tomograph equipped with a Rostock Cornea Module was performed preoperatively and at 2, 4, 8, 12 and 16 weeks postoperatively. Results: From 2 weeks onwards the epithelium demonstrated no abnormalities. Evidence of inflammation was visualized in the intermediate, basal cells and Bowman's membrane. Nerve fibre regeneration was first noted at 12 weeks. Keratocyte activation and hyperreflective extracellular matrix were observed consistently, but by 16 weeks keratocyte activation was diminished, and extracellular matrix resumed normal reflectivity. Cell density in the posterior stroma and endothelium regained preoperative values by 4 weeks, although anterior stroma keratocyte cell density was still reduced by about 10% at 16 weeks. Conclusions: Complete qualitative and quantitative characterization of corneal wound repair was achieved by in vivo confocal laser‐scanning microscopy over 16 weeks following collagen cross‐linking in rabbits. In terms of assessing the ever‐increasing range of cross‐linking protocols, in vivo confocal laser‐scanning microscopy may contribute to minimizing the number of experimental animals, because multiple examinations of the same cases are possible over time.     

Conservative treatment of keratoconus by riboflavin-uva-induced cross-linking of corneal collagen: qualitative investigation

PURPOSE: To assess corneal tissue modifications after riboflavin-UVA-induced cross-linking of corneal collagen in patients with progressive keratoconus as well as regeneration of epithelium and subepithelial nerve plexus by in vivo HRT II system confocal microscopy in humans. METHODS: Ten patients with progressive keratoconus were treated by riboflavin-UVA-induced cross-linking of corneal collagen, involving assessment of ultrastructural modifications of the corneal epithelium and subepithelial nerve plexus by HRT II system confocal microscopy. Treatment included instillation of 0.1% riboflavin-20% dextrane solution 5 minutes before UVA irradiation and every 5 minutes for a total of 30 minutes. Radiant energy was 3 mW/cm 2 or 5.4 Joule/cm 2 and the source was dual UVA (370 nm) light-emitting LED. The protocol included the operation followed by antibiotic medication and eye dressing with a soft therapeutic contact lens. Changes in epithelium and subepithelial and stromal nerve plexus were assessed by HRT II system confocal microscopy in vivo. RESULTS: After 5 days of soft contact lens wearing, corneal epithelium has a regular morphology and density. Disappearance of subepithelial stromal nerve fibers was observed in the central irradiated area where, 1 month after the operation, initial reinnervation was microscopically observed. No changes in nerve fibers were observed in the peripheral untreated with a clear lateral transition between the two areas. Six months after the operation, the anterior subepithelial stroma was recolonized by nerve fibers with restoration of corneal sensitivity. CONCLUSIONS: HRT II system confocal microscopy confirms corneal epithelium restore and re-innervation after riboflavin-UVA-induced collagen cross-linking directly in vivo in humans.     

Long-term microstructural changes following epikeratophakia: in vivo confocal microscopy study

The unilateral epikeratophakic eye of a 20-year-old woman with a history of congenital cataracts was examined using laser scanning in vivo confocal microscopy 17 years after transplantation. In vivo confocal microscopy demonstrated a reduced keratocyte density in the grafted lenticule and the host stroma, with unusual elongated and tortuous hyperreflective branching structures in the anterior stroma of the host cornea. The sub-basal nerve plexus was present in the lenticule, although with a reduced nerve density. The appearance of the host endothelium was similar to that observed in Fuchs endothelial dystrophy. Dramatic microstructural changes were observed in almost all layers of the cornea 17 years after epikeratophakia. Although no longer performed as routine practice, in vivo confocal microscopy examination of epikeratophakia has provided fascinating insight into the potential corneal adaptations at a cellular level.     

跨上皮角膜胶原交联手术治疗进展期圆锥角膜的疗效

目的:分析跨上皮角膜胶原交联手术治疗进展期圆锥角膜后1a的疗效并讨论其临床意义。方法:收集2017-01/2018-12于我院进行快速跨上皮角膜胶原交联手术的进展期圆锥角膜患者45例48眼,术后随访1a,分析手术前后视力、角膜最薄点厚度、角膜内皮细胞计数、角膜交联线深度、角膜前表面曲率Km值及角膜生物力学参数等变化情况。结果:与术前比较,本组患者术后裸眼视力明显改善(P<0.05),但最佳矫正视力、角膜最薄点厚度和角膜内皮细胞计数均无明显变化(P>0.05),术后6mo,1a角膜前表面曲率Km值(48.54±2.57、48.77±2.29D)均显著下降,角膜生物力学参数第1次压平宽度(1.52±0.21、1.57±0.22mm)均显著降低(P<0.05),第2次压平速度绝对值(0.82±0.09、0.82±0.18m/s)均显著增加(P<0.05)。结论:快速跨上皮角膜胶原交联手术治疗进展期圆锥角膜对裸眼视力有明显改善,术后角膜生物力学也有改善,但最佳矫正视力改善不明显。