应用共焦显微镜观察Fuch角膜内皮营养不良患者的病变形态学特征

目的探讨应用共焦显微镜观察我国Fuch角膜内皮营养不良患者角膜各层的活体形态学特征。方法对19例(38只眼)Fuch角膜内皮营养不良患者的中央部角膜进行活体共焦显微镜检查,分为有症状组(19只眼)和无症状组(19只眼),并选取30只眼作为正常对照组,应用NAVIS软件测量、分析角膜各层组织细胞形态和密度,以及滴状赘疣和角膜神经的直径。结果 (1)有症状组:19只眼的角膜内皮层均见到滴状赘疣,直径20-60 μm,内皮细胞密度与正常对照组比较差异有显著意义(t=18.74,P<0.01);9只眼后弹力膜增厚;14只眼角膜后基质层有长条形暗区结构;19只眼角膜基质反光普遍增强;17只眼Bowman膜有局灶性高反光区域;19只眼基底上皮细胞形态大致正常;10只眼显示正常的角膜神经结构;后、前基质细胞密度,与正常对照组比较差异无显著意义(t=0.854、1.173,P=0.38、0.24)。(2)无症状组:19只眼的角膜内皮层均见到滴状赘疣,数目较有症状组者少,直径15-40μm;内皮细胞密度,与正常对照组比较,差异无显著意义(t=1.998,P=0.053);角膜其余各层未见异常。有症状组与无症状组的内皮细胞密度计数比较,差异有非常显著意义(t=8.352,P<0.01)。结论活体共焦显微镜检查有助于Fuch角膜内皮营养不良患者的诊断,特别适用于角膜水肿、角膜内皮镜无法成像的患者。(     

应用共聚焦显微镜观察有干眼症状软性角膜接触镜配戴者的角膜神经密度

目的 利用活体共聚焦显微镜分析软性角膜接触镜配戴者干眼症状的出现与角膜上皮下神经密度的相关性.方法 前瞻性临床研究.选择无症状软性角膜接触镜配戴者20例(40眼),有症状软性角膜接触镜配戴者20例(40眼)以及从未配戴软性角膜接触镜者17例(34眼,对照组).利用活体共焦显微镜分别拍摄角膜中央、颞侧及鼻侧上皮下神经密度.比较3组眼表疾病评分问卷(OSDI)得分、角膜荧光素染色评分、泪膜破裂时间(BUT)及Schirmer Ⅰ试验结果.采用单因素方差分析.结果 各组之间BUT( F=9.04,P＜0.01),角膜荧光素评分(F=3.21,P＜0.05)差异具有统计学意义.有症状软性角膜接触镜配戴组Schirmer Ⅰ试验结果较对照组小(P＜0.05).各组间不同方位角膜神经密度比较差异无统计学意义.各组内不同方位角膜神经密度比较,鼻侧与中央、颞侧相比较小,差异均有统计学意义(P＜0.05),中央与颞侧差异无统计学意义.结论 有症状软性角膜接触镜配戴者各项客观的干眼评价指标较未配戴软性角膜接触镜者高,与无症状者基本无差异.软性角膜接触镜配戴者干眼症状的出现不会影响角膜中央、颞侧及鼻侧的神经密度.角膜神经密度中央与颞侧基本无差异,而鼻侧小于中央及颞侧.     

角膜神经损伤后再生的形态和功能学研究

采用氯化金神经组织染色法与辣根过氧化物酶逆轴浆运输法相结合，对３６只兔角膜缘穿透性切开和穿透性角膜移植术后６个月角膜神经再生情况进行动态观察。结果：１８０°角膜缘穿透性切开术后１个月，可见角膜缘细小神经分支的芽生；术后２个月，有１～２支神经再生进入角膜基质；术后６个月，有少数基质神经再生。自体穿透性角膜移植和同种异体穿透性角膜移植术后神经的再生差异无显著性。在穿透性角膜移植术后６个月，三叉神经节（ＴＧ）中标记神经元的数量仍未达到正常水平。结果表明，在角膜神经完全损伤后６个月，角膜神经再生并不能恢复正常神经密度和功能。     

角膜周边内皮细胞动态

临床角膜标本150例经锥兰,茜素红活体染色后测定角膜周边与中央内皮细胞的相对密度以及进行内皮细胞核形分析。结果表明,25例19周至34周胎儿的角膜中央和周边内皮细胞密度无显著性差别(P>0.05),而19例新生儿至53岁的角膜内皮细胞密度在角膜中央与边缘的测定数值有显著性差异(P<0.01)。胎儿角膜内皮细胞的细胞核以椭园形为主,角膜周边与中央区的细胞核形状比较相似,都处于不稳定的核形结构。出生后至成年的角膜内皮细胞核形趋于稳定,以园形为主,但在角膜缘总仍散在不稳定的椭园形细胞核,它揭示成年体角膜缘部的内皮细胞仍有部份保留着分化功能。     

三种实验动物角膜活体共焦显微镜检测的比较解剖学研究

背景 海德堡视网膜厚度分析仪和角膜模块的结合实现了对眼表活体组织结构的非侵入性检查,利用共焦显微镜对常用实验动物角膜结构进行比较研究可为相关研究提供依据.目的 利用活体共焦显微镜比较新西兰大白兔、Lewis大鼠、Swiss小鼠的角膜结构,建立实验动物角膜的活体组织图像资料,为共焦显微镜的实验研究提供依据.方法 利用海德堡视网膜厚度分析仪(HRT-Ⅱ)的Rostock角膜模块对新西兰大白兔、Lewis大鼠、Swiss小鼠的角膜进行活体分析,角膜的每一层各采集20张共焦显微镜图片,比较分析实验动物角膜各层的形态学特点及角膜内皮细胞密度.结果 共焦显微镜下3种实验动物角膜表层上皮细胞表现为高反光或低反光的多形细胞,基底上皮细胞表现为暗的细胞质,细胞核不可见,细胞间排列紧密、规则；前弹力层均表现为含有丰富上皮下神经丛的无定形物质.兔角膜基质层在黑色背景中散布着高反光物质,即为角膜基质细胞核,后基质层细胞密度高于前基质层；大鼠和小鼠的角膜基质层仅观察到大量反光的星形结构,无明显的细胞核.3种实验动物的角膜内皮细胞形态相似,均表现为高反光的胞体,边界较暗且细胞排列成蜂窝状.新西兰兔前基质角膜细胞密度中位数为387.5个/mm2,后基质角膜细胞密度中位数为223.5个/mm2,明显少于前基质的细胞密度(U=0.000,P=0.000)；新西兰兔、Lewis大鼠、Swiss小鼠角膜内皮细胞密度中位数分别为2192.5、1936.0、1565.0个/mm2,总体差异有统计学意义(H=49.940,P=0.000),兔角膜内皮细胞密度明显高于大鼠和小鼠,差异均有统计学意义(x2=0.000,P=0.000；x2=0.000,P=0.000),大鼠和小鼠的角膜内皮细胞密度差异亦有统计学意义(x2=0.000,P=0.000).结论 共焦显微镜下新西兰大白兔、Lewis大鼠、Swiss小鼠角膜各层的细胞形态相似,但内皮细胞密度和基质细胞形态之间存在明显差异.HRT-Ⅱ的Rostock角膜模块可为动物实验提供角膜各层次的高分辨率图像.     

神经营养性角膜病变

角膜感觉神经损伤导致角膜知觉减退可引起神经营养性角膜病变,可有角膜上皮脱落、角膜上皮水肿、角膜溃疡等不同的表现形式.诊断主要根据患者的病史,并要结合患者眼表情况和活体共焦显微镜检查等.通过药物和手术等合理的治疗可以阻止病程发展促进角膜上皮愈合.本文就近年来神经营养性角膜病变的病因、发病机制、诊断和治疗的研究进展做一综述.     

准分子激光术后角膜郎格罕细胞变化的实验研究

目的 观察兔PRK术后角膜格罕细胞（Langerhans cells,LCs）的变化，以及眼局部应有皮质类固醇对LCs的影响。方法 应用ATP酶染色法和透射电子显微镜技术观察PRK术后不同时间角膜上皮各区域LCs的分布、密度及其超微结构的变化。结果 PRK术后第1～7天角膜中央区基质层有炎症细胞浸润。术后第5天双眼角膜中央区上皮有LCs出现，密度逐渐增加；角膜周边区和旁中央区上皮LCs密度也逐渐增加，直至术后第21天。局部应用0.1%地塞米松眼液后角膜上皮LCs的密度减少。结论 PRK术能引起角膜上皮LCs分布改变和密度增加。术后眼局部应用皮质类固醇可以降低角膜上皮各区域LCs的密度。     

正常中国汉族儿童角膜的共焦显微镜研究

目的采用角膜激光共焦显微镜对正常中国汉族儿童活体角膜各层组织结构进行观察,分析正常中国汉族儿童角膜各层细胞的活体细胞形态学特征及密度。方法 49例6～13岁正常中国汉族儿童中央部角膜进行活体共焦显微镜检查,研究角膜各层结构的图象特点,并分析角膜各层细胞的密度,与成年人进行对比。结果中国汉族儿童正常角膜上皮表层细胞排列疏松,边界清楚,胞体较大,核反光较强,又称翼状细胞;基底层细胞排列紧密,呈规则的蜂巢状,胞质反光弱,正常情况下未见细胞核,细胞平均密度为5947.58±769.3个/mm2。前弹力膜为无细胞结构的膜状物,可见串珠状的神经纤维走行。基质层中可见在相对较暗的背景下明亮的角膜基质细胞核。角膜基质内有神经纤维分布。前基质层角膜细胞平均密度为1621.12±123.26个/mm2,后基质层角膜细胞平均密度为984.71±113.17个/mm2,前后基质层细胞密度有显著性差别（P〈0.05）。后弹力层中无细胞结构,为均一无结构组织。内皮细胞层表现为规则的六边形结构,细胞结构清晰,细胞平均密度为3682.38±251.87个/mm2。左右眼及男女之间角膜各层细胞密度的差异无统计学意义（P=0.341～0.611和P=0.194～0.855）。各层角膜细胞的面积和密度与性别和眼别无差异。中国汉族儿童角膜各层细胞的密度较正常成人高。结论角膜激光共焦显微镜能够在实时、活体和三维空间从细胞水平清晰观察中国汉族儿童活体角膜各层细胞的形态结构,可以对角膜各层结构进行定性和定量分析,在儿童角膜病的研究和临床诊断方面是十分有用的工具。     

阳离子脂质体介导的角膜内皮细胞基因转染研究

目前治疗角膜病致盲的惟一方法是角膜移植，但因供体有限且50％以上因内皮细胞密度太低而不能用。应用基因转染技术，增加活体或供体角膜内皮细胞密度有望解决这一临床难题。     

基于共聚焦显微镜图像拼接方法分析干眼患者角膜神经形态

目的：探讨使用活体共聚焦显微镜（IVCM）角膜神经图像拼接方法分析干眼患者角膜神经形态特点 及其与干眼临床指标的相关性。方法：系列病例研究。收集2021年1─5月于北京大学人民医院眼 科就诊的干眼患者16例（16眼）。所有患者均进行无创伤泪河高度（NITMH）、无创伤泪膜破裂时间 （NITBUT）、荧光素染色泪膜破裂时间（TBUT）、角膜荧光素染色（FL）评分、睑板腺缺失比例、基础 泪液分泌试验（SⅠT）、IVCM等检查。分别使用传统方法和新的拼接图像处理方法分析患者角膜上皮 下神经图像面积、神经总长度、神经密度、平均神经长度、最长神经长度、最短神经长度、神经数量、 神经数量密度等指标。纳入右眼数据进行分析。2种方法间角膜神经分析的数据比较采用wilcoxon 秩和检验。干眼临床指标与角膜神经分析数据的相关性采用Spearman相关性分析。结果：新的拼接 图像分析方法在角膜上皮下神经图像面积、神经总长度、神经密度、平均神经长度、最长神经长度、 神经数量方面均明显大于传统分析方法（均P<0.05）;最短神经长度较传统分析方法短（P<0.001）;神 经数量密度较传统方法比较差异无统计学意义。使用传统分析方法时,NIKBUT与平均神经长度、 神经数量、神经数量密度均有相关性（r=0.52,P=0.037;r=-0.62,P=0.011;r=-0.62,P=0.011）,其 余干眼指标与角膜神经指标均无相关性。而使用拼接图像分析方法时,NIKBUT与平均神经密度呈负相关（r=-0.56,P=0.025）,其余干眼指标与角膜神经指标均无相关性。结论：相比传统分析方法, 新的拼接图像分析方法可获得更大角膜神经分析面积。2种分析方法的角膜神经分析结果不同,部 分干眼指标与角膜神经分析结果的相关性也不同。新的共聚焦显微镜图像拼接分析方法能够更准确、 更可靠地评估干眼患者角膜上皮下神经情况。     

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.     

Age-related changes in rat corneal epithelial nerve density

PURPOSE: To determine the effect of aging on corneal epithelial nerve density in an animal model. METHODS: Corneal whole mounts from rats aged 6, 12, 18, and 24 months were stained immunohistochemically with antisera against the pan-neuronal marker neurotubulin. Epithelial nerve terminals and subbasal nerves in standardized 1-mm(2) central and peripheral zones from each cornea were drawn using a drawing tube attached to a light microscope. Images were scanned, and nerve densities were calculated as the percentage of each 1-mm(2) area occupied by nerves. The diameters of subbasal nerves in 6- and 24-month old animals were measured. Subbasal nerve vortices were analyzed qualitatively with reference to location, morphologic appearance, and directionality. RESULTS: Epithelial nerve terminal density decreased by approximately 50% between 6 and 24 months. The rate of decline was roughly linear and similar in both central and peripheral cornea. In contrast, subbasal nerve density increased by more than 50% between 6 and 24 months in both central and peripheral cornea. The mean diameter of corneal subbasal nerves decreased approximately 30% (0.384 microm vs. 0.271 microm) between 6 and 24 months. The morphologic appearance and directionality of the subbasal nerve vortex demonstrated considerable interanimal variability and did not correlate with age. CONCLUSIONS: Rat corneal nerve terminal density decreases, but corneal subbasal nerve density increases, as a function of age. The age-related loss of nerve terminal density seen in the rat cornea is in keeping with the decreased corneal sensitivity reported in elderly humans and may contribute to the pathogenesis of dry eye disease in aged persons.     

Altered corneal nerves in aqueous tear deficiency viewed by in vivo confocal microscopy

PURPOSE: To define the alterations of corneal nerves in aqueous tear deficiency dry eye patients with or without Sj?gren syndrome and to identify the relationship between the morphologic changes of corneal nerves and the extent of dry eye. METHODS: Confocal microscopy was used to examine 38 consecutive aqueous tear deficiency patients (8 Sj?gren syndrome and 30 non-Sj?gren syndrome) and 30 age- and gender-matched normal controls. Images taken by Confocal2 slit-scanning microscope at subbasal epithelial cell layer of central cornea were analyzed. The number and density of corneal nerves and their size, beads, tortuosity, and branching pattern were compared. These data were correlated with age and the degree of dry eye. RESULTS: Sj?gren syndrome patients showed a significant increase in average nerve number and tortuosity as compared with normal controls (P = 0.031 and 0.021, respectively). Severe nerve tortuosity (grade 4) and nerve branching appeared more frequently in aqueous tear deficiency than in normal subjects (P = 0.024 and 0.042, respectively). A decreased nerve number was observed with age in the normal controls (P = 0.002). However, such a correlation did not exist in aqueous tear deficiency. In aqueous tear deficiency, rose bengal staining score correlated positively with nerve density (P = 0.048) and nerve number (P = 0.001). Corneal fluorescein staining score was also positively correlated with nerve number (P = 0.027). CONCLUSIONS: Abnormal morphologic changes are observed in aqueous tear deficiency that are more severe in Sj?gren syndrome. The distinct changes of corneal nerves include increased nerve number, tortuosity, and chances of branching, suggesting an attempted nerve regeneration. A strong correlation exists between the changes of nerve morphology and the degree of dry eye. These results provide some possible evidence for the abnormal corneal sensation in dry eye.     

The effect of Rho Kinase inhibition on corneal nerve regeneration in vitro and in vivo

PurposeImpairment of corneal nerves can lead to neurotrophic keratopathy accompanied with severe ocular surface damage, which due to limited treatment options, can result in severe visual deterioration. This study evaluates a possible new treatment by enhancing the corneal nerve regeneration using a Rho Kinase inhibitor (Y27632). ROCK is known to play an important role in regulating cell morphology, adhesion and motility but little is known about its role in corneal nerve regeneration.MethodsEffects of ROCK inhibition on murine peripheral nerves was assessed in single cell- and wound healing assays as well as a 3D in vitro model. Furthermore, Sholl analysis evaluating neuronal branching and life-death assays evaluating toxicity of the inhibitor were performed. An in vivo mouse model was established, with monitoring weekly corneal nerve regrowth using confocal microscopy. Additionally, corneal nerve fiber length was evaluated by immunofluorescence staining. Underlying pathways were examined by qrtPCR.ResultsROCK inhibition leads to a significant enhancement of fiber growth in vitro. Sholl analysis revealed a higher degree of branching of treated fibers. Cytotoxicity assay showed no influence of Y27632 on cellular survival. In vivo measurement revealed significant enhanced regeneration after injury in the treated group. QrtPCR of trigeminal ganglia confirmed ROCK knock-down as well as altered pathways.ConclusionThe inhibition of ROCK after corneal nerve injury resulted in an enhanced regrowth of fibers in vitro and in vivo. This might be a step towards a new therapeutic concept for the treatment of impaired corneal nerves in diseases such as neurotrophic keratopathy.     

Evaluation of donor corneal endothelial viability with the vital stains rose bengal and Evans blue

Summary Two vital staining techniques, one employing rose bengal and the other Evans blue, are proposed for clinical assessment of donor corneal endothelial viability prior to keratoplasty. Both dyes selectively stained devitalized endothelial cells. Corneal perfusion studies after staining demonstrated that both stains are nontoxic to functioning endothelial cells. These staining techniques provide simple, accurate, and safe methods for evaluation donor tissue prior to corneal grafting.There is, at present, no clinically available method for accurate and safe assessment of corneal endothelial viability immediately prior to keratoplasty. While vital staining has been widely used for endothelial evaluation in experimental laboratory settings, no vital dye has been proved safe and effective for use on acutual donor corneal tissue prior to transplantation.The corneal vital stain trypan blue (Stocker, 1973) is unsuitable for use on donor tissue because of its teratogenic properties (Hamburg et al., 1975). Similarly, lissamine green (Jans and Hassard, 1967) cannot be used in clinical settings because of its carcinogenic potential (Registry of Toxic Effects of Chemical Substances, 1975).We evaluated and compared two vital staining techniques for use in evaluating donor corneal tissue prior to transplantation. The first technique used the vital stain rose bengal, originally introduced by this laboratory for experimental evaluation of corneal endothelial viability (Peyman and Spence, 1977). The second technique employed the vital stain Evans blue, and acid dye of the diazo group, which has never before-been used to assess corneal endothelial status. In this investigation, both dyes were tested against the two criteria that a vital stain for clinical use must meet: (1) the stain must be sufficiently sensitive and selective to detect increasing endothelial devitalization with increasing time of tissue refrigeration, and (2) the dye must be nontoxic to the functioning of viable endothelial cells and must be free of systematic toxicity as well.This investigation was supported in part by a grant from the Lions Foundation of Illinois.     

增龄对角膜基质载体培养的角膜缘干细胞生物学特性的影响

目的 观察增龄对新西兰兔角膜缘干细胞在同种异体角膜基质上生长、增殖的影响.方法 用酶消化法将不同年龄新西兰兔角膜缘组织制成细胞悬液培养,以相同的细胞密度种植于不同年龄的新西兰兔的角膜基质上,观察角膜缘干细胞在角膜幕质上的生长情况.原位杂交检测ABCG2、ANp63的表达,IPP5.1软件分析图像,流式细胞术测细胞周期,运用SPSS13.0软件对析因设计资料进行方差分析.结果 角膜缘干细胞供体年龄各水平差异有统汁学意义,相同时间内角膜基质培养的青年兔角膜缘干细胞在角膜基质单位面积卜的牛长总而积均较中年和老年高,增殖期细胞所占比例大;而角膜基质供体年龄各水平差异与角膜缘干细胞和角膜基质的交互作用均无统计学意义.结论 在同种异体角膜基质载体上培养的角膜缘干细胞的增殖能力随着年龄的增加而降低.     

共焦显微镜对近视人群中央角膜组织学改变与年龄相关性的研究

目的探讨共焦显微镜对近视人群中央角膜各层组织的活体观察和分析。方法选择2003年8月-2007年12月天津医科大学眼科中心进行屈光手术术前检查者122例（122眼），其中男54例（54眼），女68例（68眼）；年龄18～80岁，平均（28．54±12．4）岁；等效屈光度数为-0．50～-6．0D。检查并记录各层角膜图像，并对各层细胞形态、细胞密度进行分析。结果角膜全层厚度、基质厚度与年龄均呈负相关（r1=-0．552，P=0．014；r2=-0．545，P=0．035）。上皮层基底膜细胞密度与年龄呈负相关（r=-0．355，P=0．017）。前基质、后基质细胞密度与年龄均呈负相关（r1=-0．462；P=0．001；r2=-0．403，P=0．016）。内皮细胞密度与年龄呈负相关（r=-0．603，P=0．006）。随着年龄的增长，角膜内皮细胞发生了形态学改变，内皮细胞的多形性百分比增大，六边形细胞数的百分比下降（r1=0．417，P=0．004；r2=-0．598，P=0．002）。结论近视人群中央角膜组织随着年龄的增长，角膜上皮基底膜细胞、角膜基质细胞、角膜内皮细胞数量下降，角膜全层、角膜基质厚度减少。     

Sensory Nerve Retraction and Sympathetic Nerve Innervation Contribute to Immunopathology of Murine Recurrent Herpes Stromal Keratitis

PurposeHerpes stromal keratitis (HSK) represents a spectrum of pathologies which is caused by herpes simplex virus type 1 (HSV-1) infection and is considered a leading cause of infectious blindness. HSV-1 infects corneal sensory nerves and establishes latency in the trigeminal ganglion (TG). Recently, retraction of sensory nerves and replacement with “unsensing” sympathetic nerves was identified as a critical contributor of HSK in a mouse model where corneal pathology is caused by primary infection. This resulted in the loss of blink reflex, corneal desiccation, and exacerbation of inflammation leading to corneal opacity. Despite this, it was unclear whether inflammation associated with viral reactivation was sufficient to initiate this cascade of events.MethodsWe examined viral reactivation and corneal pathology in a mouse model with recurrent HSK by infecting the cornea with HSV-1 (McKrae) and transferring (intravenous [IV]) human sera to establish primary infection without discernible disease and then exposed the cornea to UV-B light to induce viral reactivation.ResultsUV-B light induced viral reactivation from latency in 100% of mice as measured by HSV-1 antigen deposition in the cornea. Further, unlike conventional HSK models, viral reactivation resulted in focal retraction of sensory nerves and corneal opacity. Dependent on CD4⁺ T cells, inflammation foci were innervated by sympathetic nerves.ConclusionsCollectively, our data reveal that sectoral corneal sensory nerve retraction and replacement of sympathetic nerves were involved in the progressive pathology that is dependent on CD4⁺ T cells after viral reactivation from HSV-1 latency in the UV-B induced recurrent HSK mouse model.     

2型糖尿病患者血糖控制水平与角膜神经损伤的相关性

目的　探讨2型糖尿病患者血糖控制水平与角膜神经损伤的相关性。方法　回顾性病例研究。选择2019年3月至2021年6月我院收治的2型糖尿病患者468例,根据糖化血红蛋白（HbA1c）水平将其分为A组（HbA1c＜7%,152例）、B组（7%≤HbA1c＜9%,187例）、C组（HbA1c≥9%,129例）,另外选择20位自愿者为对照组。所有受试者均接受角膜共聚焦显微镜（CCM）检查,并完善实验室检查。利用Pearson相关分析探讨受试者临床指标与CCM参数的相关性,多重线性回归分析探索影响2型糖尿病患者角膜基底膜下神经密度的相关因素。结果　C组患者角膜基底膜下神经密度、主干神经长度、主干神经数量均低于B组、A组和对照组（均为P<0.05）,主干神经弯曲均大于B组、A组和对照组（均为P<0.05）。B组患者角膜基底膜下神经密度、主干神经长度、主干神经数量均低于A组（均为P<0.05）,A组患者角膜基底膜下神经密度、主干神经长度、主干神经数量均低于对照组（均为P<0.05）。相关性分析结果显示:年龄、2型糖尿病病程、HbA1c、空腹血糖（FPG）、餐后2 h血糖（2hPG）、尿素氮（BUN）、血肌酐（Scr）与角膜基底膜下神经密度均呈负相关（均为P<0.05）,2型糖尿病病程、HbA1c、FPG与角膜基底膜下主干神经长度和数量均呈负相关（均为P<0.05）。多重线性回归分析结果显示:年龄、2型糖尿病病程、HbA1c、BUN与 2型糖尿病患者角膜基底膜下神经密度均有相关性（均为P<0.05）。结论　2型糖尿病患者血糖控制不良可能与角膜神经损伤有关。     

Putting vital stains in context

While vital staining remains a cornerstone in the diagnosis of ocular disease and contact lens complications, there are many misconceptions regarding the properties of commonly used dyes by eye‐care practitioners and what is and what is not corneal staining after instillation of sodium fluorescein. Similarly, the proper use and diagnostic utility of rose Bengal and lissamine green B, the other two ophthalmic dyes commonly used for assessing ocular complications, have similarly remained unclear. Due to the limitations of vital stains for definitive diagnosis, concomitant signs and symptoms in addition to a complete patient history are required. Over the past decade, there have been many reports of a type of corneal staining—often referred to as solution‐induced corneal staining (SICS)—that is observed with the use of multipurpose solutions in combination with soft lenses, more specifically silicone hydrogel lenses. Some authors believe that SICS is a sign of lens/solution incompatibility; however, new research shows that SICS may be neither a measure of lens/solution biocompatibility nor ‘true’ corneal staining, as that observed in pathological situations. A large component of SICS may be a benign phenomenon, known as preservative‐associated transient hyperfluorescence (PATH). There is a lack of correlated signs and/or symptoms with SICS/PATH. Several properties of SICS/PATH, such as appearance and duration, differentiate it from pathological corneal staining. This paper reviews the properties of vital stains, their use and limitations in assessment of the ocular surface, the aetiology of corneal staining, characteristics of SICS/PATH that differentiate it from pathological corneal staining and what the SICS/PATH phenomenon means for contact lens‐wearing patients.