增殖性糖尿病视网膜病变患者活体角膜组织学变化的研究

目的探讨增殖性糖尿病视网膜病变（PDR）患者角膜知觉、激光共焦显微镜下角膜上皮、神经纤维及内皮细胞的组织形态学变化。方法采用激光共焦显微镜对2006年6月至11月于玻璃体视网膜科住院的30例增殖性糖尿病视网膜病变患者进行角膜上皮、神经纤维、内皮细胞形态观察,并行角膜知觉检查;与同期白内障中心住院的同年龄30例非糖尿病患者对照。结果PDR患者角膜知觉较对照组明显减退（P〈0.001）。共焦显微镜检查显示,PDR组角膜上皮细胞、内皮细胞密度均低于对照组（P〈0.05）：角膜神经丛的密度明显低于对照组（P〈0.001）;PDR患者角膜神经纤维纤细,走行迂曲,分支减少多呈钝角。结论激光共焦显微镜已成为在活体状态下观察角膜形态的新方法,增殖性糖尿病视网膜病变患者角膜知觉减退与角膜神经纤维数目减少有关。     

糖尿病患者行玻璃体视网膜手术对角膜内皮细胞的影响

目的：探讨糖尿病患者与非糖尿病患者行玻璃体视网膜手术前后对角膜内皮细胞密度和形态学的影响。

方法：收集60例患有糖尿病患者(糖尿病组)和60例非糖尿病患者(对照组),其中30例糖尿病组和30例对照组患者行玻璃体切割联合硅油填充手术,30例糖尿病组和30例对照组患者行晶状体玻璃体切割联合硅油填充手术。检测两组患者术前1d及术后3mo角膜内皮细胞密度(cell densities,CD)、内皮细胞面积变异系数(coefficient of variation,CV)、六角形细胞百分比值(ratio of hexagonal cells,RHC)。比较两组患者手术前后角膜内皮细胞变化的差异。

结果：玻璃体切割联合硅油填充术在糖尿病组与对照组角膜内皮细胞变异系数和六角形细胞百分比手术前后相比差异均有统计学意义, 晶状体玻璃体切割联合硅油填充术在糖尿病组和对照组角膜内皮细胞密度、变异系数及六角形细胞百分比手术前后相比差异均有统计学意义; 晶状体玻璃体切割联合硅油填充术在糖尿病组手术前后角膜内皮细胞密度、变异系数、六角形细胞百分比的差值与对照组相比差异有统计学意义。

结论：玻璃体切割联合硅油填充手术对角膜的影响主要表现在角膜内皮细胞的形态改变; 而与非糖尿病患者相比,糖尿病患者行晶状体玻璃体切割联合硅油填充术角膜内皮细胞形态、密度的改变较非糖尿病患者明显,因此术前角膜内皮细胞的严格检查对于糖尿病患者术后视觉的恢复具有重要意义。     

糖尿病患者角膜内皮细胞形态学和角膜厚度研究分析

目的：通过对糖尿病患者进行角膜内皮细胞形态学定量分析,评估糖尿病对角膜内皮细胞的影响。
　　方法：应用全自动角膜内皮细胞分析仪对299例360眼进行角膜厚度及内皮细胞形态检测。正常对照组148例175眼,糖尿病患者151例185眼,其中非增殖期组患者92例110眼,增殖期组59例75眼。比较各组患者的中央角膜内皮细胞平均密度、六边形细胞比例、变异系数及角膜厚度,并进行统计学分析。
　　结果：糖尿病组与正常组角膜相比,角膜内皮细胞变异系数及中央角膜厚度增加,中央角膜平均细胞密度以及六边形细胞比例减小,差异有显著性(P<0.05)。糖尿病增殖期组与非增殖期组比较,中央角膜内皮细胞密度降低,角膜内皮细胞变异系数增加及六边形细胞比例减小,差异有显著性(P<0.05),中央角膜厚度增加,但无统计学差异(P>0.05)。
　　结论：糖尿病患者与正常对照者相比,角膜内皮细胞形态结构存在异常,并且随病变程度的加重而加重,尤其以变异系数以及六边形细胞比例变化更为显著,因此糖尿病患者角膜的抗损伤能力下降。     

Ⅱ型糖尿病患者角膜细胞形态学特征的共焦显微镜观察

目的探讨II型糖尿病患者的角膜在共焦显微镜下各层细胞形态学特征。方法应用Confoscan3.0共焦显微镜对120例(146只眼)II型糖尿病患者和36例(36只眼)同年龄对照组的中央角膜进行检查,依据双目间接眼底镜和眼底荧光血管造影检查的结果,将糖尿病患者分为三组:糖尿病无眼底改变(NDRP)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,记录角膜各层细胞的图像,并对其进行分析。结果共焦显微镜下可以观察到糖尿病引起的角膜神经营养性上皮病变;和对照组比较,2型糖尿病患者角膜上皮下神经丛神经分支密度减少,神经纤维的密度在PDR组明显减少,NPDR组、NDRP组的减少不明显。角膜基质中形态异常的神经纤维在糖尿病组中出现的机率也明显高于对照组;角膜前基质细胞密度在PDR组有明显减少,后基质细胞在NPDR组和PDR组均明显降低,NDRP组减少不明显;糖尿病组的后弹力膜层病变表现为特征性的皱折形成;糖尿病各组角膜内皮细胞密度较对照组无显著性差异,但糖尿病各组的细胞面积变异系数高于对照组,六角形细胞所占的百分比在糖尿病各组均较对照组减少,且随着糖尿病视网膜病变的进展,六角形细胞的百分比亦逐渐减少,差异有统计学意义。结论共焦显微镜检查是一种有效、无创的角膜检查方法,糖尿病对角膜每一层结构均有重要影响,角膜上皮层、角膜神经、基质细胞密度、内皮细胞密度和形态均存在改变。     

糖尿病患者角膜内皮细胞的内皮显微镜观察

使用接触型角膜内皮显微镜摄像观察了糖尿病患者６０只眼内皮细胞形态学的变化。结果表明：糖尿病患者角膜内皮细胞的密度与正常人同年龄组比较，差异无显著性；内皮细胞非六边形的比率，患者组较正常同年龄组明显升高。说明细胞构型紊乱很可能是糖尿病患者内皮细胞功能异常的病理学基础。     

2型糖尿病患者角膜基质细胞形态学特征的共焦显微镜观察

目的 探讨2型糖尿病患者在共焦显微镜下角膜基质细胞形态学特征。方法 应用Confoscan3．0共焦显微镜对120例（146眼）2型糖尿病患者和36例（36眼）同年龄对照组的中央角膜进行检查，依据双目间接眼底镜和荧光素眼底血管造影（FFA）检查的结果，将糖尿病患者分为3组：糖尿病无眼底改变（NDR）组、非增生型糖尿病视网膜病变（NPDR）组、增生型糖尿病视网膜病变（PDR）组，记录角膜基质细胞和基质神经的图像，并对其进行分析。结果 与对照组比较，糖尿病各组角膜的中基质细胞密度均较对照组降低，而前基质细胞的密度只在PDR组有明显的减少，后基质细胞在糖尿病视网膜病变组均明显降低。角膜基质中形态异常的神经纤维在糖尿病组中出现的概率也明显高于对照组，两组间有显著统计学意义（，=36．450，P=0．000）。结论 共焦显微镜是一种有效无创的角膜检查方法；2型糖尿病患者角膜基质细胞密度减少，基质细胞、基质神经均存在形态学的异常。     

高糖对兔角膜内皮细胞的形态学影响

目的：研究高糖环境下兔角膜内皮细胞形态学的变化。方法：用细胞培养的方法模拟体内高糖环境，原代培养兔角膜内皮细胞，用倒置相差显微镜和扫描电镜对高糖组及地照组进行形态学观察及分析比较。结果：高糖组角膜内皮细胞出现肿胀、六边形细胞比例减少、细胞间隙增大、细胞表面出现裂纹、微绒毛消失、细胞核皱缩等一系列的形态学改变，且这种改变程序与葡萄糖浓度基本呈正相关。结论：高糖对角膜内皮细胞存在影响，提示糖尿病病人角膜内皮细胞的修复和代偿能力下降，故当糖尿病病人进行眼部手术或存在眼部病变、损伤时，注意保护角膜内皮细胞非常重要。     

2型糖尿病患者不同视网膜病变程度下眼表及角膜病变的临床研究

目的：研究2型糖尿病患者不同视网膜病变程度下眼表及角膜病变情况。

方法：纳入我院眼科就诊的2型糖尿病患者123例246眼,根据视网膜病变程度分为无糖尿病视网膜病变组46例92眼(non-diabetic retinopathy group,NDR)、非增殖性糖尿病视网膜病变组(non-proliferative diabetic retinopathy, NPDR)50例100眼和增殖性糖尿病视网膜病变组(proliferative diabetic retinopathy, PDR)27例54眼。通过干眼问卷和眼表疾病指数量表、角膜荧光素染色(FL)、基础泪液分泌试验(SⅠt)、泪膜破裂时间检测(BUT)及中央角膜厚度测量等临床检查,分析三组不同研究对象眼表不适症状、OSDI评分、FL阳性、SⅠt、角膜内皮细胞密度(CD)、BUT、角膜内皮细胞变异系数(CV)、中央角膜厚度(CCT)的差异。

结果：三组患者一般资料差异无统计学意义。眼痛、眼干涩、流泪、眼疲劳、烧灼感、视力波动等6项眼表不适症状在三组间比较差异具有统计学意义(均P<0.05),异物感、眼痒、眼红差异无统计学意义(均P>0.05); ODSI评分分级、FL阳性率、BUT、SⅠt、CD和CCT在三组间差异具有统计学意义(均P<0.05); CV在三组间比较差异无统计学意义(P>0.05)。

结论：2型糖尿病患者具有明显的眼表不适症状; 泪膜稳定性下降、泪液分泌量减少、角膜内皮细胞密度下降; 角膜荧光素染色阳性率增加; 糖尿病患者中央角膜厚度增加,且这些变化均与糖尿病视网膜病变程度有关。     

转化生长因子β1在非增殖型糖尿病视网膜病变中的变化

目的:探讨非增殖型糖尿病视网膜病变患者血清转化生长因子(TGF-β1)和病变程度之间的关系,为糖尿病视网膜病变的早期干预寻找新的方法。方法:对经眼底血管荧光造影证实的非增殖型糖尿病视网膜病变患者(DR组)、无糖尿病视网膜病变的糖尿病患者(DM组)和健康对照组(C组)进行血清TGF-β1的测定,结果分别进行差异性比较。再按Ⅰ、Ⅱ、Ⅲ期病变将视网膜病变患者分成DR1、DR2、DR3三个亚组,再进行差异性比较。结果:血清TGF-β1水平DM组与C组差异无显著性。DR组分别高于DM和C组,差异显著。DR1分别比DR2、DR3低,差异均显著。DR2、DR3两组差异无显著性。结论:非增殖型糖尿病视网膜病变患者血清TGF-β1是升高的,并能部分反映病变的严重程度。对其血清中TGF-β1的测定可以在某种程度上提示干预的时间。     

白内障患者术前角膜内皮细胞分析

目的分析不同白内障患者术前角膜内皮情况,以评估角膜对手术的耐受程度。方法白内障198例（277只眼）,按伴有的眼病不同分为7个组。所有患者术前检测角膜内皮细胞密度、细胞平均面积、六角形细胞比例。采用SPSS16．0进行单因素方差分析。结果急性闭角型青光眼组和增生性糖尿病视网膜病变组与正常组（不伴有其他眼病的单纯老年性白内障）比较,二者角膜内皮细胞密度下降,细胞平均面积增大,差异有统计学意义（P〈0．05）。前者六角形细胞比例未见明显下降;后者六角形细胞比例下降。慢性闭角型青光眼组、非增生性糖尿病视网膜病变组、高度近视组、陈旧性葡萄炎组与正常组比较,三项指标差异均无统计学意义（P〉0．05）。结论急性闭角型青光眼、增生性糖尿病视网膜病变均可对角膜内皮产生影响;而慢性闭角型青光眼、非增生性糖尿病视网膜病变、高度近视、陈旧性葡萄炎对角膜内皮细胞形态没有明显影响。     

Evaluation of corneal endothelium morphology in diabetic patients

PURPOSE: To evaluate the influence of diabetes mellitus and type of hipoglicemic therapy on corneal endothelium cell morphology. MATERIAL AND METHODS: In 68 diabetic patients' eyes with non proliferative diabetic retinopathy (29 males and 39 females), corneal endothelium was studied. Patients age was between 50 and 82 years (mean 63.28). As age-matched control group we analyzed 58 eyes of non diabetic patients. Corneal endothelium density, percentage of corneal endothelium hexagonal cells, average size of corneal endothelium cells and corneal thickness were imaged by non-contact specular microscope TOPCON SP-2000P. RESULTS: The mean corneal endothelium cell density was: 2467 cells/mm2 in diabetic patients, and 2573 cells/mm2 in control group. The mean percentage of corneal endothelium hexagonal cells was: 55.3% in diabetic patients treated with insulin and 52.9% in diabetic patients treated with oral antidiabetic drugs, and 54.4% in the control group. The mean size of corneal endothelium cells was: 414.6 microm2 in diabetic patients, and 395.9 microm2 in the control group. The mean corneal thickness was: 0.556 mm in diabetic patients and 0.545 mm in the control group. CONCLUSIONS: Corneal endothelium was thicker in diabetic patients than in non diabetic patients. The duration of diabetes mellitus had no influence on corneal endothelium cell morphology. Diabetic patients treated with oral antidiabetic drugs had larger percentage of hexagonal cells than those treated with insulin.     

Corneal endothelial cell change after phacoemulsification relative to the severity of diabetic retinopathy

PURPOSE: To investigate the differences in corneal endothelial cell morphology between diabetic patients who were divided by the degree of the severity of diabetic retinopathy and normal patients after phacoemulsification with intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, College of Medicine, Pusan National University, Pusan, Korea. METHODS: Before and 6 months after phacoemulsification, specular microscopy was used to evaluate the number and morphology of endothelial cells in patients with diabetic retinopathy. The patients were divided into 3 groups: group I (n=30 eyes), without diabetes; group II (n=30 eyes), diabetes with severe nonproliferative diabetic retinopathy; group III (n=30 eyes), diabetes with high-risk proliferative diabetic retinopathy (PDR). RESULTS: Postoperative corneal endothelial cell density and hexagonality were significantly decreased and the coefficient of variation in cell size increased in all groups, in contrast to the preoperative state (P<.05). During the postoperative 6 months, the percentage of hexagonal cells showed a tendency to decrease progressively, and this was a significant difference between the 3 groups (P<.05). However, the patterns of change in endothelial cell density and the coefficient of variation in cell size were not different between the groups (P>.05). At the postoperative 6 months, the corneal endothelial cell density and the coefficient of variation in cell size of high-risk PDR patients were statistically changed compared with normal persons (P<.05). However, the percentage of hexagonal cell was not significantly difference between diabetic retinopathy patients and normal patients (P>.05). CONCLUSIONS: Corneal endothelial cell density significantly decreased and the coefficient of variation in cell size significantly increased for high-risk PDR patients undergoing phacoemulsification, in contrast to normal persons at the postoperative 6 months.     

The epidemiology of diabetic retinopathy

The paper presents a statistic study of the incidence of the diabetic retinopathy in patients who have been recently taken into evidence in the Antidiabetic Centre Timi?oara. These patients were diagnosed between 1994 and 1997. The incidence of the diabetic retinopathy in Romania is more significant than in other countries like USA, France, UK, Finland. The prevalence of the diabetic retinopathy is significant too being placed around the value of 0.02-0.03%. When diabetes mellitus was found, the incidence of nonproliferative diabetic retinopathy was placed around 8% while the incidence of proliferative diabetic retinopathy was placed around 1%. The diabetic retinopathy is more often diagnosed in patients insulin dependent. After 20 years of diabetes mellitus evolution, 80% of the insulin dependent patients and 60% of the noninsulin dependent patients present diabetic retinopathy with a more or less important impact on the visual function.     

Corneal endothelial morphology and central thickness in patients with type II diabetes mellitus

Purpose: To investigate corneal endothelial cell density and morphology in type II diabetic and non‐diabetic patients and to relate potential differences to the glycaemic status. Methods: A prospective clinical study including 107 patients with type II diabetes and 128 non‐diabetic patients. Sample size was based on a power calculation (power = 0.90; p = 0.05). The diabetic patients had on average more than four HbA1c tests performed (mean 4.1; range 2–14) with intervals of at least 3 months as a reflection of the long‐term glycaemic status. The controls had no diabetes confirmed by two causal blood tests. The endothelial cell density, the variation in endothelial cell size (CV), the percentage of hexagonal cells, and the central corneal thickness (CCT) were recorded. Results: Type II diabetic subjects did not differ from the non‐diabetic control subjects with regards to endothelial cell density, hexagonality or variation in CV, but showed a significant increase in CCT (538 versus 546 μm, p < 0.05). In the diabetic group, lower cell counts were associated with higher HbA1_c values (p < 0.05). The HbA1c did not, however, have any impact on the CCT. Conclusion: Type II diabetes has no impact on corneal cell density or morphology in subjects with good glycaemic status. However, higher HbA1c was associated with lower endothelial cell density. CCT was significantly increased in the diabetic group_.     

Structural and functional studies of the corneal endothelium in diabetes mellitus.

We performed specular microscopy, anterior segment ocular fluorophotometry, corneal pachymetry, and tonometry on 14 patients with chronic type I diabetes and nonproliferative retinopathy and on 14 age-matched control subjects. The eyes of patients with diabetes had an increased coefficient of variation of endothelial cell area, a decreased percentage of hexagonal endothelial cells, increased corneal autofluorescence, and increased intraocular pressure, which confirmed previous studies. There was no difference, however, in corneal thickness or endothelial permeability to fluorescein. Thus, we were unable to detect any abnormality in endothelial function in these diabetic corneas in the unstressed state, despite structurally abnormal endothelial cells.     

Corneal changes in type II diabetes mellitus in Malaysia

AIM: To compare corneal endothelial structure and central corneal thickness (CCT) between type II diabetics and non-diabetic control patients. To look for correlations between diabetic status and corneal findings. METHODS: Hospital-based, observational study. 200 eyes (from 100 type II diabetic patients and 100 controls) were included. Specular microscopy and pachymetry were used to measure endothelial cell density, size, coefficient of variation in cell area, hexagonality as well as corneal thickness. Independent t-tests were used to compare variables between diabetics and controls. Pearson correlation tests were used to evaluate correlations between corneal findings and diabetic status such as duration of diabetes, haemoglobin A1c (HbA1c) level and severity of diabetic retinopathy. RESULTS: Endothelial cell density in the diabetic group (2541.6±516.4 cells/mm2) was significantly lower than that in the control group (2660.1±515.5 cells/mm2, P <0.05). The average size of endothelial cells, standard deviation (SD) of cell size and coefficient of variation (CV) of cell area were all significantly higher in diabetics. Hexagonality was significantly lower in diabetics (41.1%±19.6%) compared to non- diabetics (45.2%±20.6%). CCT was higher in diabetics but not significant (P >0.05). Duration of diabetes, HbA1c level and severity of diabetic retinopathy were not significantly correlated with corneal endothelial findings. CONCLUSION: Type II diabetes causes a significant alteration in the state of the cornea including reduction in endothelial cell density and increased pleomorphism and polymegathism. Central corneal thickness is unaffected.     

The corneal endothelium and thickness in type II diabetes mellitus

PURPOSE: To compare the endothelial structure and thickness of the cornea in diabetic and nondiabetic patients, and to evaluate the systemic and ocular factors that contribute to the damage of endothelial cells in diabetic patients. METHODS: The corneal endothelial structure and central corneal thickness (CCT) were investigated in 99 type II diabetic patients (99 eyes) and in 97 nondiabetic patients (97 eyes). The endothelial structure was examined for cell density, coefficient of variation of cell area, and percentage of hexagonal cells. The correlation between CCT and the grade of diabetic retinopathy was evaluated. Multivariate regression analysis was performed to assess systemic factors (patient age, sex, duration of diabetes mellitus, hemoglobin A(1c) value, glucose in urine, blood urea nitrogen value, and creatine value) and ocular factors (grade of diabetic retinopathy and history of photocoagulation) related to endothelial cell density. RESULTS: The endothelial cell density was decreased and the coefficient of variation of cell area was increased in diabetic patients (P <.05). However, the percentage of hexagonal cells and CCT in diabetic patients was not significantly different from that in nondiabetic patients. CCT was similar regardless of the stage of diabetic retinopathy. Multivariate regression analysis indicated that none of the systemic or ocular factors was significantly correlated with the endothelial cell density. CONCLUSIONS: Corneal endothelial cell structure was damaged, but CCT was not increased in type II diabetic patients. There were no systemic or ocular factors at any one point to induce corneal endothelial damage.     

Relationship of corneal endothelial morphology to diabetic retinopathy, duration of diabetes and glycemic control

Using specular microscopy and computer-assisted morphometry, the morphologic features of the corneal endothelium were evaluated in three groups of patients with type II diabetes mellitus: 20 patients without diabetic retinopathy, 24 with background retinopathy, and 26 with proliferative retinopathy. When compared to age-matched nondiabetic controls (30 patients), all diabetic groups had similar endothelial cell densities but demonstrated significant increases in cell size and shape variability (pleomorphism). However, there was no significant difference in the degree of these endothelial changes among the three diabetic groups. Moreover, none of the endothelial morphologic parameters was found to correlate with the duration of diabetes or glycemic control, as estimated from glycosylated hemoglobin (HbA1) concentrations.     

The corneal endothelium of diabetic patients. A study using specular microscopy

As the endothelial cells of the human cornea cannot perform mitosis, any metabolic alteration that destroys the cells should result into a decrease in cell density. This study was designed to demonstrate this phenomenon in diabetics as we know that diabetes alters endothelial cells, capillaries at least. On the assumption that capillary endothelium has the same mesodermal origin and almost the same metabolic function as the corneal endothelium, we tried to verify whether the corneal endothelium from diabetic subjects differs from non diabetic controls. As corneal endothelium can be studied in vivo by specular microscopy, it was interesting to verify whether this method could provide evidence of the conditions of the endothelial cells in the diabetic subject. Our study in specular microscopy involved 101 cases. We found slightly inferior values of the corneal endothelial cells density in diabetic subjects compared to the control subjects but no correlation between the values of endothelial cell density and the various parameters in diabetic patients: age, duration of diabetes, corneal thickness. This is correlated to other studies in which the morphology of endothelial cells differed between diabetic and non-diabetic subjects. We concluded that diabetes alters but does not significantly destroy the corneal endothelial cell. This result must be taken into account in corneal surgery as the diabetic cornea is a high risk cornea.     

Corneal endothelium evaluation in type I and type II diabetes mellitus.

BACKGROUND: The purpose of this study is to evaluate the corneal endothelium in type I and type II diabetic patients. METHODS: Seventy-five diabetics divided into type I and type II groups and 62 healthy volunteers took part in the study. The mean endothelial cell density and morphology, and the central corneal thickness were evaluated and statistical analysis was done. RESULTS: All evaluated parameters were found to be significantly different in both diabetic groups with reduction of the mean cell density of 5% in type II and of 11% in type I diabetes with respect to the normal age-matched control group. Important alterations of endothelial morphology were observed. The central corneal pachymetry was significantly higher in diabetics, with p < 0.01 in the type I group and p < 0.05 in the type II group. CONCLUSION: It is concluded that corneal endothelium in diabetics should still be considered as a tissue under continuous metabolic stress with consequent high vulnerability, especially in case of any external insult such as a surgical procedure.