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。     

干眼患者活体角膜组织学变化

目的：应用共焦显微镜观察不同程度的泪液生成不足型和蒸发过强型干眼患者的角膜细胞学变化。

方法：本研究采用回顾性系列病例研究。选择临床上根据患者病史、症状、角结膜体征及相关仪器检查确诊为蒸发过强型干眼患者33例65眼和泪液生成不足型干眼患者28例55眼。应用三维断层角膜地形图及眼前节分析系统(Sirius系统)对所有干眼患者的严重程度进行分级。应用共焦显微镜对其角膜上皮层(表层上皮细胞层、翼状上皮细胞层和基底上皮细胞层)、朗格汉斯细胞(树突状细胞)、基质层(浅基质和深基质)、内皮层的细胞密度、形态进行观察和分析。

结果：共焦显微镜显示泪液生成不足型和蒸发过强型干眼患者角膜上皮层的细胞数量随干眼的严重程度增加而减少,差异有统计学意义(P<0.01)。两种类型干眼角膜上皮各层细胞大小不均,排列欠规则。泪液生成不足型干眼的角膜上皮下神经纤维直径变细,排列不规则,随着干眼严重程度的增加其弯曲度逐渐增大、分支增多。蒸发过强型干眼朗格汉斯细胞的活化程度与干眼的严重程度成正比,差异有统计学意义(P<0.01)。干眼患者角膜浅基质层细胞数量和深基质层细胞数量变化差异无统计学意义(P>0.05)。两种类型干眼患者的角膜内皮细胞数量无明显变化,差异无统计学意义(P>0.05)。

结论：应用Sirius系统可对两种类型干眼的严重程度进行非接触无创检查并分类,共焦显微镜观察分类后的两种干眼类型患者的角膜各层细胞密度及形态存在变化。     

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。     

新型冠状病毒引起的病毒性角膜炎病例观察

目的：报告3例严重急性呼吸综合征冠状病毒2型(SARS-CoV-2)引起的病毒性角膜炎。

方法：对3例新冠感染确诊患者行裂隙灯、眼压、角膜荧光染色、前段照相、活体共聚焦显微镜(IVCM)和常规眼底筛查。治疗包括更昔洛韦眼用凝胶、人工泪液和糖皮质激素滴眼液。

结果：3例SARS-CoV-2角膜炎(SCK)患者经标准治疗后恢复良好。

结论：SARS-CoV-2角膜炎通常表现为角膜上皮下浸润,可导致角膜上皮下神经纤维密度降低和树突状细胞(DC)增加。抗病毒治疗联合糖皮质激素已被证明是有效的。     

Ⅱ型糖尿病患者角膜的共聚焦显微镜观察

目的共聚焦显微镜下观察Ⅱ型糖尿病患者角膜上皮下神经纤维以及角膜各层细胞密度和形态学改变。设计比较性病例系列。研究对象选取确诊为Ⅱ型糖尿病的患者20例(20眼)为病例组和就诊于眼科门诊的无糖尿病的老年性白内障患者20例(20眼)为对照组。方法病例组和对照组均进行角膜共聚焦显微镜检查,对所得的图片和结果进行分析。主要指标角膜上皮下神经纤维密度、角膜上皮基底细胞密度、角膜浅基质细胞密度、角膜中基质细胞密度、角膜深基质细胞密度、角膜内皮细胞密度、内皮细胞的变异系数和六角形百分比。结果糖尿病组与对照组相比,上皮下神经纤维密度明显减少(t=-4.951,P=0.000);角膜浅基质细胞密度、中基质细胞密度和深基质细胞密度均有显著下降(P值均=0.000);角膜内皮细胞变异系数增加(t’=3.652,P=0.001),六角形百分比减少(t=-3.778;P=0.001)。结论共聚焦显微镜下显示Ⅱ型糖尿病患者角膜上皮下神经纤维密度和各层细胞密度下降。     

后弹力层剥除联合角膜内皮移植手术技巧在大泡性角膜病变中的应用

目的：观察改良的角膜后弹力层剥除联合自动角膜刀取材内皮移植术(DSAEK)手术技巧在大泡性角膜病变中的应用。

方法：回顾性分析2018-12/2019-12在我科住院治疗的大泡性角膜病变患者10例10眼,均行DSAEK术,除常规手术步骤,术中在前房灌注管设置、切口设计及角膜周边穿刺等手术技术上进行改进。术后随访6mo,观察角膜植片恢复情况和植片脱位、前房反应等并发症发生情况,评估最佳矫正视力(BCVA)、角膜中央厚度(CCT)、角膜内皮细胞计数(ECD)情况。

结果：所有患者均顺利完成手术,无术中并发症发生,术后未见植片脱位和层间积液发生。术后眼压正常,BCVA较术前均有不同程度改善。角膜畏光、眼磨等刺激症状自术后 1d开始逐渐减轻,术后2wk完全缓解。术后1mo角膜基质水肿消退,CCT(596.8±19.11μm)较术前(874.0±58.64μm)明显变薄。随访期间,所有患者病情稳定,角膜植片保持透明,但角膜内皮细胞计数均有不同程度衰减。

结论： DSAEK术中手术技巧的改进可以明显减少大泡性角膜病变患者术中和术后并发症,提高手术安全性和有效性。     

角膜基质透镜在角膜溃疡或穿孔修复中的应用

目的：研究由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植材料治疗角膜溃疡的临床疗效。

方法：回顾性病例研究。收集本院2017-01/06角膜溃疡患者6例6眼,其中细菌性、真菌性、深层异物伴感染各1例1眼,角膜穿孔3例3眼。采用由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植的材料进行修复手术,确保植片与角膜层间无空气间隙。术后随访1～6(平均3.71±1.56)mo,观察手术前后视力、角膜移植物存活情况及术后并发症发生情况等。

结果：所有患者均在控制感染下顺利完成手术,无术中并发症。术后所有角膜植片透明。末次随访时,患者最佳矫正视力(best corrected visual acuity,BCVA)较术前明显改善(0.48±0.12 vs 1.50±0.08),差异具有统计学意义(P<0.01)。

结论：来源于全飞秒激光屈光手术的角膜基质透镜用于角膜溃疡修复是安全有效的,但植片的远期疗效尚需进一步观察。     

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。     

DR早期视网膜神经纤维层和角膜神经的变化及其相关性

目的:观察无视网膜微血管病变的糖尿病患者的视网膜神经纤维层(RNFL)和角膜神经纤维(CNF)变化,以及两者变化的相关性.方法:收集40例40眼2型糖尿病患者,经散瞳眼底检查未发现糖尿病视网膜病变,均接受光学相干断层扫描(OCT)检查和活体角膜共聚焦显微镜(IVCM)检查.另收集年龄匹配的80例80眼健康正常眼为对照,分为40例40眼只行OCT检查的RNFL对照组和40例40眼只行IVCM检查的CNF对照组.利用OCT观察视乳头上方、下方、颞侧、鼻侧和平均RNFL厚度,用IVCM观察角膜上皮下角膜神经纤维长度和角膜神经密度.结果:糖尿病组的视乳头上方、颞侧、鼻侧及平均RNFL与对照组比较,差异无统计学意义(P>0.05),但视乳头下方RNFL糖尿病组比RNFL对照组减少,差异有统计学意义(P=0.003).糖尿病组的角膜神经纤维长度、角膜神经密度均比CNF对照组减少(P<0.01).糖尿病组中,平均RNFL与角膜神经纤维长度和角膜神经密度呈正相关(r=0.518,P<0.01;r=0.484,P=0.002),下方RNFL与角膜神经纤维长度和角膜神经密度呈正相关(r=0.607,P<0.01;r=0.573,P<0.01).结论:糖尿病患者在未发现糖尿病视网膜病变前同时存在视网膜神经纤维层和角膜神经的丢失,视网膜神经纤维层变薄主要表现在下方象限,视网膜神经纤维层的变薄与角膜神经的减少呈正相关.     

In vivo confocal microscopy of Fleck dystrophy and pre-Descemet's membrane corneal dystrophy

PURPOSE: To assess the value of in vivo confocal microscopy (CM) in the diagnosis of Fleck dystrophy and pre-Descemet's membrane corneal dystrophy. METHODS: Case report of two patients. Standard slit-lamp and ophthalmic examination and in vivo CM were performed on both patients. The thickness of the cornea and the morphology of the corneal epithelium, stroma, endothelium, and subbasal nerves were evaluated by confocal microscopy. RESULTS: Biomicroscopy revealed bilateral, fine, dust-, and flour-like opacities in the corneal stroma for the Fleck dystrophy patient. In the pre-Descemet's membrane corneal dystrophy patient, biomicroscopy showed opacities larger than those in the first patient. Both patients were then examined by in vivo CM. Confocal microscopy of the Fleck dystrophy showed intracellular deposits throughout the stroma. In pre-Descemet's membrane corneal dystrophy, however, these and the extracellular deposits were observed immediately anterior to Descemet's membrane. The thicknesses of the corneas were 560 and 650 microm for Fleck and pre-Descemet's membrane corneal dystrophy, respectively. The surface epithelium, subbasal nerves, and endothelium showed normal morphology in both patients. CONCLUSION: In vivo CM is a valuable tool in diagnosing rare corneal dystrophies when the final diagnosis is difficult to obtain with conventional methods.     

Autosomal recessive cornea plana: in vivo corneal morphology and corneal sensitivity

PURPOSE: Autosomal recessive corneal plana (RCP) is a rare corneal anomaly with unknown pathogenesis and a high incidence in Finland. The aim was to examine corneal sensitivity and the morphology of different corneal layers and subbasal nerves in RCP patients. METHODS: Three patients with a diagnosed autosomal recessive cornea plana were examined. Corneal sensitivity to different modalities of stimulation was tested in four corneas using noncontact esthesiometry. Tissue morphology of three corneas was evaluated, and in two corneas thickness of corneal layers was measured using in vivo confocal microscopy. RESULTS: Corneas of RCP patients appear to have mechanosensory, polymodal, and cold-sensitive nerve terminals. RCP patients had normal sensation thresholds for chemical, heat, and cold stimulation but a high threshold for mechanical stimulation. Their capacity to discriminate increasing intensities of stimulus was reduced, except for cold stimuli. Thickness of the epithelial layer was reduced, whereas total corneal and stromal thicknesses were slightly reduced or close to normal values. In all cases Bowman's layer was absent. Subbasal nerves had abnormal branching patterns. The arrangement of anterior keratocytes was altered, showing clustered and irregularly shaped nuclei. Increased backscattering of light in confocal microscopy through focusing (CMTF) profiles was observed throughout the stroma. Epithelial and endothelial cells appeared to be regular in shape. CONCLUSIONS: The present study revealed qualitative and quantitative alterations in corneal sensitivity, cellular morphology, and the thickness of corneal layers in RCP patients.     

Corneal nerves alterations in various types of systemic polyneuropathy, identified by in vivo confocal microscopy

BACKGROUND: In vivo confocal microscopy (IVCM) is a newly developed application to assess corneal nerve morphology. The purpose of the study is to evaluate the role of IVCM in the assessment of various types of polyneuropathy, and to define alterations of corneal nerves in such conditions. PATIENTS AND METHODS: Eighteen patients with various types of polyneuropathy were characterized by clinical neurological and ophthalmic examinations, as well as by electroneuromyography (ENMG). Full thickness IVCM of corneal nerves was carried out on all patients and 15 age-matched eyes using Heidelberg Retina Tomograph II (HRT II). The subbasal nerve plexus were statistically analysed regarding long nerve fiber density, nerve branch density, nerve thickness, nerve bead number and nerve tortuosity. RESULTS: In subbasal nerve plexus, the following three parameters were significantly reduced in patients with polyneuropathy compared to controls: long nerve fibre density (p < 0.01), nerve branch density (p < 0.001), and nerve bead number (p = 0.001). In addition, the average grade of nerve tortuosity was 2.87 +/- 0.97 in the polyneuropathic group and 1.17 +/- 0.68 in the control group (p < 0.0001). CONCLUSIONS: IVCM allows a non-invasive, in vivo study of corneal nerves with high resolution. It therefore appears invaluable in clinical investigations. IVCM appears to be valuable in a large variety of polyneuropathic conditions.     

In vivo confocal microscopy after herpes keratitis

PURPOSE: To describe the confocal microscopic findings, with special reference to corneal subbasal nerves, after herpes simplex virus (HSV) keratitis. METHODS: In this study, 16 HSV eyes and 14 contralateral eyes of 16 patients, diagnosed with unilateral HSV keratitis 1-12 months earlier by the presence of dendritic corneal ulceration or microbiologic confirmation, were examined by in vivo confocal microscopy for evaluation of corneal morphology. RESULTS: Herpes simplex virus eyes: In 2 eyes the surface epithelial cells appeared large, and no abnormalities were observed in the basal epithelial cells. In 2 eyes subbasal nerve fiber bundles were completely absent, in 3 eyes there was a reduced number of long nerve fiber bundles, and in 11 eyes the subbasal nerve plexus appeared normal. In 10 corneas, highly reflective dendritic structures were found at the level of the basal epithelial cells. Frequently these structures were found in the vicinity of stromal fibrosis. Areas with increased abnormal extracellular matrix were found in 11 eyes. Stromal nerves were not visualized in all corneas, but appeared normal when observed. Contralateral eyes: No abnormalities were observed in the epithelium. All corneas presented with a normal subbasal nerve plexus, but in 2 eyes dendritic particles were observed. Three corneas presented with activated keratocytes and increased amounts of abnormal extracellular matrix. CONCLUSIONS: When visualized by confocal microscopy, the subbasal nerve plexus appears relatively unaffected in cases with resolved HSV keratitis. Unidentified dendritic structures, presumably Langerhans cells, are frequently seen at the level of the basal epithelium in corneas with a history of herpetic disease.     

圆锥角膜基底下神经与角膜形态的相关性研究

目的 研究圆锥角膜（KC）基底下神经与角膜形态的相关性。设计 前瞻性比较性病例系列。研究对象 2018年3月至2019年3月北京同仁医院KC患者（KC组）74例74眼,KC顿挫期组25例25眼,正常对照组24例24眼。方法 通过眼部检查及Pentacam眼前节分析仪诊断KC、KC顿挫期及正常角膜。角膜形态参数采用Pentacam的角膜最大曲率值（Kmax）和角膜最薄厚度值（Minpachy）。应用ACCmetrics软件计算由活体激光共聚焦显微镜（IVCM）获得的基底下神经图片上六种基底下神经参数：角膜神经纤维密度（CNFD）、角膜神经分支密度（CNBD）、角膜神经纤维长度（CNFL）、角膜总分支密度（CTBD）、角膜神经纤维面积（CNFA）、角膜神经纤维宽度（CNFW）。分析KC组角膜基底下神经与角膜形态的相关性,并比较各两组间角膜基底下神经参数的差异。主要指标 Kmax、Minpachy、CNFD、CNBD、CNFL、CTBD、CNFA、CNFW。结果 IVCM定性分析观察到KC组角膜基底下神经迂曲度增加、基底下神经纤维密度明显低,偶可见神经呈束状排列。KC组和正常对照组比较,CNFD、CNBD、CNFL和CNFW差异均有统计学意义（P均<0.05）。KC组和顿挫组比较,CNFL和CNFA差异均有统计学意义（P均<0.05）。顿挫组和正常对照组比较,CNFD和CNFL差异均有统计学意义（P均<0.05）。KC组CNFD、CNFL和CNFW分别与Kmax具有相关性（P=0.001、0.001和0.006）, KC组的CNFD、CNBD、CNFL和CNFW分别与Minpachy具有相关性（P=0.01、0.01、0.004和0.02）。结论 KC患者角膜基底下神经的改变可能早于角膜形态的改变,基底下神经随着疾病的进展而变化。CNFD和CNFL可能是诊断早期圆锥角膜的指标。（眼科, 2020, 29： 118-122）     

In vivo confocal microscopy of patients with corneal recurrent erosion syndrome or epithelial basement membrane dystrophy

OBJECTIVE: To characterize morphologic changes in corneas of patients with recurrent erosion syndrome or epithelial basement membrane dystrophy using in vivo confocal microscopy. DESIGN: Observational case series PARTICIPANTS: Fourteen eyes of eight patients with diagnosed epithelial basement membrane dystrophy and 13 eyes of seven patients with recurrent erosion syndrome were examined. METHODS: Slit-lamp examination and in vivo confocal microscopy. The pathologic findings are presented as digitized images obtained from video tape recorded during the confocal microscopy. MAIN OUTCOME MEASURES: The morphology of corneal surface epithelial cells, basal epithelial cells, subbasal nerve plexus, Bowman's layer, stromal keratocytes, and endothelium was analyzed. RESULTS: The surface epithelium was intact in all but two eyes. One cornea (a basement membrane disorder with clinically visible dots) had multinucleate surface epithelial cells, and one eye with recurrent corneal erosions showed a freely floating surface epithelium sheet in the tear fluid. Patients in both groups showed islets of highly reflective cells with presumed intracellular deposits surrounded by normal cells in the basal epithelial cell layer. The basal epithelial cell area also showed other pathologic changes, including drop-shaped configurations, streaks, or ridges. Folding of the Bowman's layer was also observed in both groups. Anterior keratocytes showed signs of activation (highly reflective nuclei with visible processes) in some of the patients regardless of the clinical diagnosis, and in recurrent erosions even increased deposition of abnormal extracellular matrix in the anterior stroma was suspected. Posterior corneal keratocytes and endothelium appeared normal when examined. The subbasal nerve plexus showed various pathologic changes, such as short or strangely shaped nerve fiber bundles, decreased numbers of long nerve fiber bundles, only faintly visible long nerve fiber bundles (instead of the normally observed long parallel running interconnected bundles), or increased amounts of Langerhans cells, but only one patient (with recurrent erosion syndrome) lacked the subbasal nerve plexus. CONCLUSIONS: In vivo confocal microscopy of corneas with recurrent erosions or epithelial basement membrane dystrophy showed deposits in basal epithelial cells, subbasal microfolds and streaks, damaged subbasal nerves, or altered morphology of the anterior stroma. Confocal microscopy cannot replace biomicroscopy in making a specific diagnosis, but it sometimes helps the diagnosis in corneas that appear normal under a biomicroscope.     

Innervation of tissue-engineered corneal implants in a porcine model: a 1-year in vivo confocal microscopy study

PURPOSE: To examine the pattern of nerve regeneration within tissue-engineered corneal substitutes grafted into host porcine corneas over a 1-year postoperative period. METHODS: Biodegradable corneal substitutes from cross-linked collagen were implanted into the left eyes of 12 pigs by deep lamellar keratoplasty. Regeneration of severed nerves into the central implant region was investigated with in vivo confocal microscopy. Both implant-recipient and control (right) eyes were examined before surgery and 2, 6, 10, and 12 months after surgery, to quantify the number, density, diameter, and branching of nerve fiber bundles at various corneal depths. Transmission electron microscopy was used to confirm the presence of nerve bundles. RESULTS: Two months after surgery, corneal nerve ingrowth was observed within the deep anterior stroma, with a number and density of regenerated nerves significantly higher than in nonsurgical control eyes (P < 0.01). Nerves within the superficial anterior stroma regenerated by 6 to 10 months after surgery, and the first subbasal epithelial nerves were seen 10 months after surgery. After 1 year, subbasal nerve density recovered to preoperative levels. Nerve fibers in the deep anterior stroma remained significantly thinner relative to control eyes after 1 year (P < 0.001), where both superficial anterior and subbasal nerve diameter did not change relative to control eyes. CONCLUSIONS: The pattern of reinnervation within tissue-engineered corneal substitutes has been quantified in vivo. Innervation proceeded rapidly in the deep anterior stroma, followed by repopulation of more superficial regions. One year after surgery, nerve density within the tissue-engineered cornea increased or remained unchanged relative to controls in all corneal regions examined.     

Corneal Nerve and Epithelial Cell Alterations in Corneal Allodynia: An In Vivo Confocal Microscopy Case Series

Purpose

To investigate morphological changes of the corneal epithelium and subbasal nerves in patients with corneal allodynia using in vivo confocal microscopy (IVCM).

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.