角膜激光共焦显微镜在糖尿病视网膜病变中的应用

目的　探讨角膜激光共焦显微镜在观察糖尿病视网膜病变（diabetic retinopathy,DR）患者角膜上皮下神经丛、角膜细胞密度及形态变化中的价值。方法　选取确诊的DR患者94例（114眼）,其中非增生型糖尿病视网膜病变（non-proliferative diabetic retinopathy,NPDR）患者41例（52眼,NPDR组）、增生型糖尿病视网膜病变（proliferative diabetic retinopathy,PDR）患者53例（62眼,PDR组）,收治时间2016年1月至2017年4月,同期糖尿病无眼底改变的患者40例（40眼）作为对照组,三组均采用角膜激光共焦显微镜进行检测,对比各组角膜上皮下神经丛、角膜细胞密度及形态的变化。结果　NPDR组和PDR组患者的角膜基底层、浅基质层、中基质层、深基质层的细胞密度均显著低于对照组（均为P<0.05）;PDR组患者的角膜基底层、浅基质层、中基质层、深基质层的细胞密度均显著低于NPDR组（均为P<0.05）;NPDR组和PDR组患者的角膜内皮细胞密度、六边形细胞比例、神经纤维密度、神经纤维长度均显著低于对照组（均为P<0.05）,NPDR组和PDR组患者的内皮细胞变异率、神经分支密度均显著高于对照组（均为P<0.05）;PDR组患者的角膜内皮细胞密度、六边形细胞比例、神经纤维密度、神经纤维长度分别为（1962.0±117.3）个·mm^-2、46.1%±5.5%、（15.4±3.3）根·mm^-2、（6.2±2.7）mm·mm^-2,均显著低于NPDR组的（2381.4±144.0）个·mm^-2、58.2%±7.0%、（20.6±3.8）根·mm^-2、（8.6±2.4）mm·mm^-2（均为P<0.05）,PDR组患者的内皮细胞变异率、神经分支密度均显著高于NPDR组（均为P<0.05）。结论　角膜激光共焦显微镜能有效观察DR患者角膜上皮下神经丛、角膜细胞密度及形态变化,为临床诊断、治疗提供指导。     

Morphology of corneal nerves using confocal microscopy

PURPOSE: The aim of the current study was to evaluate the distribution and morphology of corneal nerves as seen by means of white light confocal microscopy. METHODS: This study analyzed images of corneal nerves that were obtained using the Tomey Confoscan slit scanning confocal microscope (40x/0.75 objective lens). The images were classified according to their location within the cornea. The objective and subjective evaluation of the images involved measuring, grading, or judging a number of parameters from both individual pictures and from each single nerve fiber within any image. RESULTS: The in vivo observations made in this work are in agreement with those of previous histologic studies. The general scheme of corneal innervation is described as originating from thick and straight stromal nerve trunks that extend lateral and anteriorly and give rise to plexiform arrangements of progressively thinner nerve fibers at several levels within the stroma. From there, nerve fibers perforate Bowman's layer and eventually form a dense neural plexus just beneath the basal epithelial cell layer, which is characterized by tortuous and thin beaded nerve fibers interconnected by numerous nerve elements; nerve fibers from this plexus are known to be responsible for the innervation of the epithelium. CONCLUSION: This study provides convincing evidence of the suitability of confocal microscopy to image corneal nerves, the only drawback being the limited resolution in terms of the differentiation of the ultrastructure of nerve bundles.     

Clinical corneal confocal microscopy

Confocal microscopy allows non-invasive in vivo imaging of the ocular surface. Its unique physical properties enable microscopic examination of all layers of the cornea and have been used to investigate numerous corneal diseases: epithelial changes, numerous stromal degenerative or dystrophic diseases, endothelial pathologies, corneal deposits, infections, and traumatic lesions. It offers a new approach to study the physiological reactions of the cornea to different stimuli and the pathophysiologic events leading to corneal dysfunction in certain diseases. Confocal microscopy proves to be a powerful diagnostic tool and is especially of value in certain corneal diseases by allowing straightforward and non-invasive recognition of the pathologic conditions.     

基于角膜共焦激光显微镜检测的角膜基底神经变化与2型糖尿病视网膜微血管病变的相关性研究

目的 探讨角膜共焦激光显微镜检测的角膜基底神经变化与2型糖尿病(type 2 diabetes mellitus,T2DM)视网膜微血管病变的相关性.方法 选取2016年2月至2017年2月在我院治疗的T2DM患者118例,其中合并糖尿病视网膜病变(diabetic retinopathy,DR)患者57例(DR组),无DR患者61例(NDR组),同时选取健康志愿者60人作为对照组,所有研究对象采用角膜共焦激光显微镜检查,分析角膜神经形态参数与临床指标的关系.结果 DR组角膜神经纤维密度、角膜神经分支密度和角膜神经长度分别为(20.03±4.22)条·mm-2、(22.01 ±7.05)条·rnm-和(9.50±1.76)mm· mm-2,明显小于对照组和NDR组(均为P＜0.05),而角膜神经纤维弯曲度为0.30±0.03,明显高于对照组和NDR组(均为P＜0.05);DR患者中,Ⅲ期患者角膜神经纤维密度、角膜神经分支密度和角膜神经长度明显小于Ⅰ期和Ⅱ期DR患者(均为P＜0.05),而角膜神经纤维弯曲度明显高于Ⅰ期和Ⅱ期DR患者(均为P＜0.05).DR组病程为(12.04±2.48)a,明显高于NDR组(P＜0.05),而空腹C肽和空腹胰岛素分别为(1.41 ±0.58) μg·L-1和(20.05 ±7.91)mU·L-1,明显低于NDR组(均为P＜0.05).T2DM患者病程与角膜神经分支密度及角膜神经纤维长度呈负相关(r=-0.322、-0.317,均为P＜0.05);空腹C肽与角膜神经分支密度呈正相关(r =0.298,P＜0.05),与角膜神经弯曲度呈负相关(r=-0.311,P＜0.05).结论 T2DM视网膜微血管病变患者角膜神经形态参数异常,对病程较长或空腹C肽水平低的T2DM患者应用角膜共激光显微镜检测有助于早期发现微血管病变.     

糖尿病视网膜病变严重程度与角膜内皮细胞变化之间的相关性

目的 了解糖尿病视网膜病变(diabetic retinopathy,DR)严重程度与角膜内皮细胞细胞形态和数量变化的相关性.方法 采用日本Topcon角膜内皮计对101例(201眼)确诊为DR的患者行5个方位角膜内皮检查,以DR新的国际临床分级标准进行分期,比较不同分期DR之间角膜内皮细胞密度、平均面积、面积标准差、面积变异系数、六角形细胞比例以及中央角膜厚度等各参数的变化.结果 Ⅰ期患者平均角膜内皮细胞面积为(380.11±33.42)μm2、内皮细胞密度为(2 741.03±247.45)mm-2、六角形细胞比例为(52.14±6.85)%、平均中央角膜厚度(0.59±0.03)mm;而Ⅴ期患者各数值已分别变为(412.26±52.88)μm2、(2 508.39±398.60)mm-2、(48.99±5.74)%和(0.55±0.03)mm.以上各指标在Ⅰ期和Ⅱ期间差异均无统计学意义(均为P>0.05),但Ⅲ期、Ⅳ期和Ⅴ期平均角膜内皮细胞面积、内皮细胞密度及平均中央角膜厚度与Ⅰ期、Ⅱ期比较,差异有统计学意义(P<0.05).Ⅳ期、Ⅴ期六角型细胞比例和细胞面积变异系数与Ⅰ期、Ⅱ期比较,差异有统计学意义(均为P<0.05).结论 随着DR严重程度增加,角膜内皮呈现细胞密度降低、平均细胞面积增加、六角形细胞比例及平均中央角膜厚度数值减少.提示糖尿病可对患者的视网膜和角膜组织造成明显损害,且二者损害程度一致.     

In vivo corneal confocal microscopy in keratoconus

PURPOSE: To evaluate the corneas of keratoconic subjects using in vivo confocal microscopy. METHODS: Slit scanning confocal microscopy was used to evaluate the central cornea of one eye of each of 29 keratoconic subjects (mean age 31 +/- 10 years; range 16-49 years). Quantitative aspects of corneal morphology were compared against data from control subjects. RESULTS: Compared with normal control corneas, epithelial wing cell nuclei were larger (p < 0.0001) and epithelial basal cell diameter was larger (p < 0.05) in the keratoconic cornea. Many of the keratoconic corneas investigated showed increased levels of stromal haze and reflectivity, which appeared to be related to the presence of apical scarring on slit lamp examination. A grading scale was devised to quantify the levels of haze. This scale was shown to provide a measure of the level of scarring present. The anterior keratocyte density (AKD) and posterior keratocyte density were 19% lower (p < 0.0001) and 10% lower (p = 0.004) than in controls, respectively. The reduction in AKD was significantly associated with three factors: a history of atopy, eye rubbing and the presence of corneal staining. The mean endothelial cell density in keratoconus was 6% greater than that of normal controls (p = 0.05). The level of endothelial polymegethism was shown not to be different between keratoconic subjects and matched controls (paired t-test: t = 1.82, p = 0.08). CONCLUSIONS: Confocal microscopy demonstrates significant quantitative alterations of corneal morphology in keratoconus.     

活体共聚焦显微镜在角膜病临床研究中的新进展

活体共聚焦显微镜能在细胞水平实时、非侵入性、高清晰地检测角膜结构,它已广泛应用于角膜病的研究.本文对活体共聚焦显微镜在感染性角膜炎、圆锥角膜、角膜后沉着物、长期应用抗青光眼药物引起的角膜病变及糖尿病相关的角膜病变的临床研究新进展进行综述.     

In vivo confocal corneal microscopy after keratoplasty

BACKGROUND: Seven eyes with clear grafts after penetrating keratoplasty were examined with in vivo confocal corneal microscopy in 1999. Our aim was the confocal microscopic investigation of the subclinical changes in clear grafts after long-term follow-up.METHODS: The preoperative diagnoses were keratoconus (two), granular corneal dystrophy (two), pseudophakic bullous keratopathy due to ACL (two), and corneal ulcer (one). The epithelium, corneal nerves, keratocytes of the anterior and posterior stroma, and endothelium were evaluated with confocal microscopy.RESULTS: Mean density of basal epithelial cells was 3928+/-378 cells/mm(2) at 15 months and 3284+/-565 cells/mm(2) at 66 months postoperatively. At 15 months the keratocyte density was 750+/-113 cells/mm(2) in the anterior stroma and 601+/-98 cells/mm(2) in the posterior stroma, at 66 months 383+/-53 cells/mm(2) in the anterior stroma and 411+/-98 cells/mm(2) in the posterior stroma. Endothelial cell density decreased from 1719+/-576 cells/mm(2) (15 months) to 965+/-272 cells/mm(2) (66 months).CONCLUSIONS: In the follow-up period a significant decrease of keratocyte and endothelial cell density was detectable with confocal microscopy. The clinical importance of our findings must be clarified with further examinations on more patients.     

Microstructural assessment of rare corneal dystrophies using real-time in vivo confocal microscopy

Purpose : To analyse and describe three cases of rare corneal dystrophy and highlight their in vivo microstructural features. Methods : Subject 1 was diagnosed with a posterior stromal fleck corneal dystrophy. Two of her three children were also affected. Subjects 2 and 3 exhibited an almost identical clinical appearance on biomicroscopic examination, such that both clinically were diagnosed as having pre‐Descemet’s dystrophies. All subjects underwent in vivo confocal microscopy and approximately 300 sequential digital images were obtained and analysed for each cornea. Results : In vivo confocal microscopy of subject 1 demonstrated an abnormal appearance of numerous large ovoid particles, measuring 50–70 μm in diameter in the mid and posterior stroma as well as smaller hyperreflective dot‐like intracellular deposits, of less than 1 μm diameter. Despite the near‐identical clinical appearance, subjects 2 and 3 could be clearly differentiated by in vivo confocal microscopy. Subject 2 exhibited small, irregular, optically dense particles, mainly in the anterior stroma, whereas subject 3 possessed classical involvement of the stroma immediately adjacent to Descemet’s membrane, with numerous regular, small, hyperreflective particles. Conclusions : The ability of in vivo confocal microscopy to localize and accurately measure various elements in different corneal layers may help to resolve whether abnormalities are intra‐ or extracellular, and aid clearer differentiation of rare corneal disorders.     

共焦显微镜观察2型糖尿病患者角膜神经分布及形态学特征

目的探讨2型糖尿病患者共焦显微镜下的角膜神经分布及形态学特征。方法应用Confoscan3．0共焦显微镜观察59例（65只眼）2型糖尿病患者和26例（26只眼）同年龄对照组白内障手术患者的中央角膜神经分布和形态学特征,依据双目间接检眼镜和荧光素眼底血管造影检查结果,将糖尿病患者分为3组：糖尿病无眼底改变（NDR）组、非增生性糖尿病视网膜病变（NPDR）组、增生性糖尿病视网膜病变（PDR）组,记录并分析患者角膜上皮下神经丛和角膜基质神经图像。结果与对照组相比,2型糖尿病患者角膜上皮下神经丛神经分支密度、神经纤维长度均减少,差异有统计学意义（P〈0．01）,神经纤维的密度仅PDR组明显减少,NPDR组、NDR组减少不明显。角膜基质中形态异常的神经纤维在糖尿病患者中出现的几率也明显高于对照组,两组差异有统计学意义（P〈0．01）。结论共焦显微镜是一种有效、无创的角膜神经检查方法,2型糖尿病患者角膜上皮下神经丛、角膜基质神经均显示形态学异常。（中华膑群杂志,2006,42：896—900）     

糖尿病视网膜病变合并视神经病变的临床分析

目的探讨糖尿病视网膜病变合并糖尿病性视乳头病变和缺血性视神经病变两类疾病的发病特点及其发生与DR分期的相关性。方法回顾性分析诊断为DR的1126例患者2034只眼的眼底彩照、FFA与视野等资料,筛选出糖尿病性视乳头病变11例15眼,糖尿病缺血性视神经病变24例27眼,分析两组患者的年龄、眼别、视力、糖尿病病程、主诉等临床资料,并分析两类疾病的发生与DR分期的相关性。结果(1)DR合并DP发病率为0.74%,合并ION的发病率为1.33%,两类疾病在视力下降程度、糖尿病病程等方面都有不同。(2)背景期DR合并DP和ION的发病率高于增殖期DR。结论DR合并视神经病变并不少见,对于DR患者不明原因的视力下降,应考虑合并视神经病变的发生,以免延误患者病情。     

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.     

糖尿病性角膜神经病变的研究进展

糖尿病性角膜神经病变是一种潜在的致盲性病变,观察角膜神经超微结构变化,探讨其发病机制,以及探索其有效的预防治疗措施是非常重要的。本文就糖尿病角膜神经细胞病理形态变化,及其病变机制的研究进展作一综述。     

In vivo corneal confocal microscopy in marfan syndrome

PURPOSE: To examine the cornea of patients with Marfan syndrome in comparison with a control group by using the in vivo confocal microscope. METHODS: Twenty-four eyes of 12 patients with Marfan syndrome had their corneas examined using the in vivo confocal microscope Heidelberg Retina Tomograph (HRT) II/Rostock Cornea Module. The control group included 24 eyes of 12 subjects who had their corneas examined by the same in vivo confocal microscope. RESULTS: Epithelium and neural plexus examination did not show any difference between the 2 groups. Examination of the stroma showed no significant differences concerning the morphology and density of keratocytes. The extracellular matrix of 16 of the 24 eyes of the Marfan group was clearly visible and showed thin highly reflective interconnected lines between keratocytes. In the healthy eye group, reflective lines were observed in only 5 of the 24 eyes. The endothelium of 14 corneas of the Marfan group showed brightly reflective particles. In no cornea of the control group were such particles observed. CONCLUSIONS: Highly reflective extracellular matrix of the stroma and brightly reflective particles among the endothelial cells were the 2 main corneal findings observed by using in vivo corneal confocal microscopy in patients with Marfan syndrome compared with a control group. Further studies need to be made to confirm these findings and eventually find new criteria for Marfan syndrome from the examination of in vivo corneal confocal microscopy.     

Central corneal thickness: z-ring corneal confocal microscopy versus ultrasound pachymetry

PURPOSE: To compare the repeatability and validity of corneal pachymetry by a corneal confocal microscope with a z-axis adapter (Confoscan 4.0 with z-ring adapter: z-CS4) versus ultrasound (US) pachymetry in the measurement of central corneal thickness (CCT). METHODS: CCT in 44 eyes of 44 subjects was determined with z-CS4. Z-CS4 exams were used to estimate the repeatability of thickness measurement by z-ring adapter for this confocal microscope. Intraclass Correlation Coefficient (ICC) between two different z-CS4 users was also determined. CCT in the same 44 eyes was determined with US pachymetry and measurements were compared with z-CS4 CCT. RESULTS: Z-CS4 CCT showed high intrainstrument reproducibility (ICC = 0.989; 95%CI 0.982-0.993; P < 0.0001). Mean difference among three CCT consecutive measures, in the same eye, was 0.8 +/- 11.1 microm. High correlation was found between two users (ICC = 0.896; 95%IC 0.830-0.937; P < 0.0001). Z-CS4 CCT showed high correlation with US pachymetry (ICC = 0.921; 95%CI 0.851-0.958; P < 0.0001). Mean corneal thickness determined was statistically different with the two methods (US: 512.6 +/- 65.8 microm; z-CS4: 487.8 +/- 60.1 microm; P < 0.0001). CONCLUSION: Z-CS4 seems an accurate, noninvasive and reproducible technique for CCT evaluation and confirms that central cornea is thinner when measured with confocal microscopy compared to ultrasounds.