泪膜与眼表微环境的研究进展

泪膜覆盖眼表,是眼表微环境的重要组成部分,其稳态失衡可以造成眼表其他细胞和组织结构与功能异常,从而加重眼表疾病的发生和发展。笔者旨在对泪膜与眼表微环境中其他的成分包括眼表上皮、角膜基质、角膜神经和眼表微生物群的作用方面进行综述,以期为眼表疾病的发病机制研究及诊疗提供新的思路。     

角膜缘干细胞微环境的研究进展

角膜上皮的更新及损伤后修复有赖于角膜缘干细胞功能正常.角膜缘干细胞的增生及相关特性受干细胞微环境的调控影响.近年研究表明,角膜缘干细胞微环境包括干细胞龛三维结构、干细胞龛中存在的各种细胞类型、细胞分泌的细胞因子及角膜缘特异的基底膜.其中角膜缘细胞外基质和邻近细胞对角膜缘干细胞的调节尤为重要.模拟角膜缘干细胞微环境构建组织工程角膜对实现眼表重建,为患者带来复明希望具有重要意义.     

角膜神经相关眼病的研究进展

角膜神经是眼表的重要结构,对于维持角膜正常结构和功能起着重要的作用.多种眼部手术(屈光手术、角膜移植术)、多种眼表疾病(单纯疱疹性角膜炎、干眼症)、全身疾病(糖尿病),乃至长期使用滴眼药物都将影响角膜神经的形态和功能.正常角膜神经的缺失将导致角膜的营养不良及代谢障碍.从角膜神经的解剖、生理与病理、创伤愈合与修复、与角膜神经异常有关的眼病、神经再生以及问题与展望等六个部分进行综述,便于更好地理解角膜神经的构造和功能,为更好地开展保护角膜神经工作做一铺垫.     

角膜神经及P物质在病毒性角膜炎中的研究进展

角膜神经在维持角膜的健康和功能方面发挥关键作用,病毒性角膜炎等疾病可致其损伤。近年来研究发现单侧角膜病变不仅影响患侧的角膜神经,对侧眼的神经也会受累;此外,除了负责角膜知觉的感觉神经发生改变,病毒性角膜炎还可以影响交感神经。但临床除了共聚焦显微镜和角膜知觉外,尚缺乏评估角膜神经损伤程度及预后的有效指标。角膜神经通过释放神经肽发挥多种作用,其中P物质作为首个局部应用于临床的神经肽,被证明可以调控病毒感染的病理过程,并通过促炎、营养等多种作用参与病毒性角膜炎双眼角膜病变的进展,具有潜在的辅助诊断及治疗价值。因此本文对角膜神经和神经肽P物质在病毒性角膜炎中的改变及作用进行综述,为相关机制的基础研究及临床应用提供参考。     

角膜发育的分子调控机制研究进展

角膜的发育异常可引起先天性角膜内皮营养不良、Peters异常、Axenfeld—Rieger综合征及眼表鳞状上皮瘤（OSSN）等先天性眼病。角膜的发育经历了从诱导、发生到逐渐成熟的过程,在此期间的细胞增生、凋亡、分化等一系列过程受到多种信号转导通路和转录因子的精确调控。近年来通过胚胎的组织和基因操作技术,人们发现了一系列信号转导通路,如骨形态发生蛋白（BMP）、成纤维细胞生长因子（FGF）、Notch等,和多种转录因子,如Pax6、Krfippel样因子6（KLF6）、转化生长因子8（TGF-β）、TGF—α等均参与了角膜的发育调控过程,它们分别或协同作用于角膜发育的不同阶段,发挥各自的重要功能。主要介绍几种已知在角膜胚胎发育过程中起重要作用的信号转导通路和细胞因子。     

糖尿病对眼表结构的影响

糖尿病是全身系统性疾病,可发生多种并发症,严重威胁人类健康。糖尿病性眼表病变包括结膜微血管瘤、干眼、角膜上皮损伤和角膜知觉减退等,这些疾病均可严重影响患者生活质量。糖尿病对眼表的破坏作用包括角膜神经损伤、角膜上皮结构和功能异常、泪液质和量改变、降血糖药物影响等四方面。     

糖尿病对眼表结构的影响

糖尿病是全身系统性疾病,可发生多种并发症,严重威胁人类健康.糖尿病性眼表病变包括结膜微血管瘤、干眼、角膜上皮损伤和角膜知觉减退等,这些疾病均可严重影响患者生活质量.糖尿病对眼表的破坏作用包括角膜神经损伤、角膜上皮结构和功能异常、泪液质和量改变、降血糖药物影响等四方面.     

神经营养性角膜炎诊治的研究进展

神经营养性角膜炎(NK)是由三叉神经支配受损引起的退行性角膜疾病，可导致自发性角膜上皮破裂、角膜溃疡甚至穿孔。诸多破坏三叉神经支配的疾病均可导致NK。NK的早期诊断十分重要，需要准确收集和审查患者病史并进行完善的眼表检查，从而确定临床分期。NK的治疗需基于疾病严重程度进行分期治疗，除了人工泪液、睑裂缝合术、羊膜移植术等传统的内外科疗法，目前还有如靶向药物治疗和角膜神经化手术等新兴疗法。本文总结了NK的流行病学、临床表现及分类、病因、诊断、鉴别诊断及治疗，旨在为未来早期诊断和分期治疗NK提供参考。     

Smad蛋白调控角膜新生血管发生发展的研究进展

角膜新生血管（CNV）是一种严重的致盲性病理改变,与多种眼表疾病的发生发展密切相关。在CNV发生发展过程中,多种蛋白参与调控。研究表明,Smad蛋白可通过多种信号通路影响CNV的发生发展。本文就近年来Smad蛋白调控CNV发生发展的研究进展作一综述。     

糖尿病角膜神经病变的研究现状

角膜神经的正常分布具有保护眼表、维持角膜知觉等重要作用.糖尿病角膜神经病变可以引起角膜感觉异常、组织损伤、视力受损等表现,发病机制尚未完全阐明,主要与糖代谢紊乱、周围神经病变、氧化应激等有关.研究认为糖尿病角膜神经纤维缺失或长度、密度降低与角膜敏感性、糖尿病视网膜病变、干眼症等因素相关,其主要治疗方法包括控制血糖、营养神经、促神经生长等.     

In Vivo Confocal Microscopy of Corneal Nerves in Health and Disease

In vivo confocal microscopy (IVCM) is becoming an indispensable tool for studying corneal physiology and disease. Enabling the dissection of corneal architecture at a cellular level, this technique offers fast and noninvasive in vivo imaging of the cornea with images comparable to those of ex vivo histochemical techniques. Corneal nerves bear substantial relevance to clinicians and scientists alike, given their pivotal roles in regulation of corneal sensation, maintenance of epithelial integrity, as well as proliferation and promotion of wound healing. Thus, IVCM offers a unique method to study corneal nerve alterations in a myriad of conditions, such as ocular and systemic diseases and following corneal surgery, without altering the tissue microenvironment. Of particular interest has been the correlation of corneal subbasal nerves to their function, which has been studied in normal eyes, contact lens wearers, and patients with keratoconus, infectious keratitis, corneal dystrophies, and neurotrophic keratopathy. Longitudinal studies have applied IVCM to investigate the effects of corneal surgery on nerves, demonstrating their regenerative capacity. IVCM is increasingly important in the diagnosis and management of systemic conditions such as peripheral diabetic neuropathy and, more recently, in ocular diseases. In this review, we outline the principles and applications of IVCM in the study of corneal nerves in various ocular and systemic diseases.     

Genomics of corneal wound healing: a review of the literature

Corneal wound healing is a complex process: its mechanisms and the underlying genetic control are not fully understood. It involves the integrated actions of multiple growth factors, cytokines and proteases produced by epithelial cells, stromal keratocytes, inflammatory cells and lacrimal gland cells. Following an epithelial insult, multiple cytokines are released triggering a cascade of events that leads to repair the epithelial defect and remodelling of the stroma to minimize the loss of transparency and function. In this review, we examine the literature surrounding the genomics of corneal wound healing with respect to the following topics: epithelial and stromal wound healing (including inhibition); corneal neovascularisation; the role of corneal nerves in wound healing; the endothelium; the role of aquaporins and aptamers. We also examine the effect of ectasia on corneal wound healing with regard to keratoconus and following corneal surgery. A better understanding of the cellular and molecular changes that occur during repair of corneal wounds will provide the opportunity to design treatments that selectively modulate key phases of the healing process resulting in scars that more closely resemble normal corneal architecture.     

角膜基质修复的机制和调控因素研究进展

角膜基质是维持角膜透明度的重要结构。外伤、感染、手术等可造成角膜基质损伤,引起修复的过程包括基质细胞表型改变、细胞外基质重塑、免疫细胞迁移。当基质严重受损,肌成纤维细胞增多和细胞外基质沉积发生基质纤维化反应,形成角膜瘢痕,是全球致盲的主要原因。目前治疗方式主要是角膜移植手术,因角膜供体资源短缺、手术技巧要求和术后移植排斥风险等治疗效果不佳。近年来,各种分子、细胞和组织对角膜基质损伤修复的调控机制取得一定研究进展。本文就角膜基质损伤修复的机制和角膜损伤原因、角膜结构、分子因素对角膜基质损伤修复的调控进行综述,为探索促进角膜基质修复和再生的途径提供新思路,希望帮助临床预防角膜瘢痕的发生。     

组织工程角膜上皮移植重建眼表面的临床研究

目的 观察组织工程角膜上皮移植重建眼表面治疗完全性角膜上皮干细胞缺乏的短期临床效果.方法 系列病例研究.6例(6眼)单眼全角膜缘干细胞缺乏患者,包括碱烧伤3例、爆炸伤2例、热烧伤1例.采用去上皮羊膜组织作为载体,体外扩增患者自体健眼角膜上皮干细胞,构建组织工程角膜上皮.然后进行组织工程角膜上皮移植重建眼表面.术前及术后检查指标包括裸眼视力、裂隙灯显微镜、超声生物显微镜、泪液分泌试验.结果 患者自体来源的角膜上皮干细胞在去上皮羊膜上培养3周后均可形成直径15 mm的复层上皮片.组织工程角膜上皮均成功移植于所有受体眼表面.移植术后3个月,所有患者角膜上皮完整光滑,角膜瘢痕及纤维血管翳明显减轻,6例患者视力均有不同程度的提高.结论 患者自体来源的角膜上皮干细胞构建的组织工程角膜上皮移植可以成功重建全角膜缘干细胞缺乏患者的眼表面,为这类患者的复明带来希望.     

In Vivo Confocal Microscopy of Corneal Nerves: Analysis and Clinical Correlation

Corneal confocal microscopy is a growing technique for the study of the cornea at the cellular level, providing images comparable to ex vivo histochemical methods. In vivo confocal microscopy (IVCM) has an enormous potential, being a noninvasive procedure that images the living cornea, to study both its physiological and pathological states. Corneal nerves are of great interest to clinicians and scientists due to their important roles in regulating corneal sensation, epithelial integrity, proliferation, wound healing, and for their protective functions. IVCM enables the noninvasive examination of corneal nerves, allowing the study of nerve alterations in different ocular diseases, after corneal surgery, and in systemic diseases. To date, the correlation of sub-basal corneal nerves and their function has been studied in normal eyes, keratoconus, dry eye, contact lens wearers, and in neurotrophic keratopathy, among others. Further, the effect of corneal surgery on nerves has been studied, demonstrating the regenerative capacity of corneal nerves and the recovery of sensation. Moreover, IVCM has been applied in the diagnosis of peripheral diabetic neuropathy and the assessment of progression in this systemic disease. The purpose of this review is to describe the principles, applications, and clinical correlation of IVCM in the study of corneal nerves in different ocular and systemic diseases.     

In vivo confocal microscopy of corneal nerves: analysis and clinical correlation

Corneal confocal microscopy is a growing technique for the study of the cornea at the cellular level, providing images comparable to ex vivo histochemical methods. In vivo confocal microscopy (IVCM) has an enormous potential, being a noninvasive procedure that images the living cornea, to study both its physiological and pathological states. Corneal nerves are of great interest to clinicians and scientists due to their important roles in regulating corneal sensation, epithelial integrity, proliferation, wound healing, and for their protective functions. IVCM enables the noninvasive examination of corneal nerves, allowing the study of nerve alterations in different ocular diseases, after corneal surgery, and in systemic diseases. To date, the correlation of sub-basal corneal nerves and their function has been studied in normal eyes, keratoconus, dry eye, contact lens wearers, and in neurotrophic keratopathy, among others. Further, the effect of corneal surgery on nerves has been studied, demonstrating the regenerative capacity of corneal nerves and the recovery of sensation. Moreover, IVCM has been applied in the diagnosis of peripheral diabetic neuropathy and the assessment of progression in this systemic disease. The purpose of this review is to describe the principles, applications, and clinical correlation of IVCM in the study of corneal nerves in different ocular and systemic diseases.     

角膜疾病应用基础研究的现状和策略

我国在角膜应用基础研究的层次和规模方面尚与国际先进水平存在差距，缺少意义重大、思路创新、促进学科发展的研究。除外部因素，眼科研究人员本身亦应对本专业的现状、进展、发展趋势等有基本了解，才能促进新理论、新观点、新技术的产生。本文围绕角膜上皮干细胞、基质内抗原提呈细胞、角膜内皮细胞三种重要细胞以及角膜感染、营养不良和移植失功三种重要病理过程，结合国内外的研究现状，分析我国角膜病基础研究领域可拓展的方向和策略。     

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。     

Mapping the entire human corneal nerve architecture

We developed an approach to generate a three-dimensional map that facilitates the assessment of epithelial nerve density in different corneal areas to define aging and gender influence on human corneal nerve architecture. Twenty-eight fresh human eyes from 14 donors of different ages were studied. Corneal nerves were stained and consecutive images acquired with a fluorescence microscope, recorded at the same plane, and merged for viewing the complete epithelial and stromal nerve architecture. After whole mount examination, the same cornea was also used for transection. Stromal nerves entered the cornea in a radial pattern, subsequently dividing into smaller branches. Some branches connected at the center of the stroma, but most penetrated upward into the epithelium. No differences were observed between nerve densities in the four corneal quadrants. Epithelial innervation in the limbal and most of the peripheral area was supplied by a superficial network surrounding the limbal area. Central epithelial nerves were supplied by branches of the stromal nerve network. Epithelial nerve density and terminal numbers were higher in the center of the cornea, rather than the periphery. There were no differences in epithelial nerve density between genders, but there was a progressive nerve density reduction concomitant with aging, mainly in eye samples of donors 70-years of age and older. The modified technique of tissue preparation used for this study allowed for observation of new nerve structure features and, for the first time, provided a complete view of the human corneal nerve architecture. Our study reveals that aging decreases the number of central epithelial nerve terminals, and increases the presence of irregular anomalies beneath the basal layer.     

角膜上皮重建的研究进展

角膜上皮的增生与更新依赖于角膜缘干细胞，角膜缘干细胞缺乏可导致视力障碍。组织工程化角膜上皮的研究是眼科研究的一个热点。我们就近年来在组织工程角膜上皮重建中应用的非眼来源干细胞的新进展作一简要综述。