Multifocal oscillatory potentials in type 1 diabetes without retinopathy

PURPOSE: To study multifocal recordings of oscillatory potentials (m-OPs) in diabetic (Type 1) eyes that have no visible fundus alterations, to ascertain whether topographical changes in sensitivity are evident when compared with recordings from control subjects. METHODS: The Visual Evoked Response Imaging System (VERIS; EDI, San Diego, CA) system was used to elicit m-OPs from 61 independent areas, subtending the central 30 degrees of the retina, from 24 eyes of 12 patients with diabetes without retinopathy and from 26 eyes of 14 control subjects. For each group of subjects, the mean first- and second-order (first slice) kernel components of the responses for one eye, randomly chosen from each subject, were analyzed and compared for a retinal ring analysis and for an analysis of retinal quadrants. RESULTS: Both first- and second-order kernel responses of the diabetic group show significant delays in the implicit times of some of the m-OPs, compared with those of the control group. No significant changes in amplitude were found. For the first-order component, significant differences are found for both potentials between 5 degrees and 22 degrees eccentricity, for the nasal retina, and for one of the potentials for the remaining retinal areas. In the second-order kernel responses, the differences are significant for two of the three potentials in the midperiphery between 5 degrees and 13 degrees eccentricity, with the central potential being significantly delayed in all rings and quadrants. CONCLUSIONS: Patients with diabetes without retinopathy show prolonged latencies in m-OP recordings. This indicates an alteration in inner retinal sensitivity that can be explained by an impaired rod-cone interaction.     

The prevalence of retinopathy in subjects with and without type 2 diabetes mellitus

Purpose:  To evaluate the prevalence of and risk factors for, retinopathy in a geographically defined population with type 2 diabetes mellitus compared with a control group of subjects without diabetes, matched by age, sex and residence in order to find the retinopathy attributable to type 2 diabetes. Methods:  The study populations are, on one hand, a prevalence cohort of subjects with type 2 diabetes resident in the community of Laxå, Sweden, and on the other a control group, matched by age, gender and residence with those with a diagnosis of type 2 diabetes mellitus. Retinopathy was graded from fundus photographs using a modification of the Early Treatment Retinopathy Study (ETDRS) adaptation of the modified Airlie House classification of diabetic retinopathy (DR). Results:  Any retinopathy was found in 34.6% in the type 2 diabetes cohort and in 8.8% in the control group without diabetes. Among the diabetic patients, any retinopathy was significantly associated with duration of diabetes (p = 0.0001), HbA1c (p = 0.0056), systolic blood pressure (p = 0.0091) and lower serum cholesterol (p = 0.0197) in multivariate logistic regression analyses. Having retinopathy in the control group was associated only with systolic blood pressure (p = 0.0014) in logistic regression analysis. Conclusions:  The prevalence of retinopathy among patients with type 2 diabetes in Laxå, Sweden, was similar or somewhat lower compared with other studies in the Nordic countries. The prevalence of retinopathy in a control group without diabetes equalled numbers from population studies worldwide. Our study indicates that the retinopathy that can be attributed to hyperglycaemia in the diabetic state is less common than is usually accounted for. A considerable fraction of retinopathy in subjects with diabetes may instead be due to other factors such as hypertension and should thus be treated correspondingly.     

无明显糖尿病视网膜病变的2型糖尿病患者多焦视网膜电图特征分析

目的 观察眼底无明显糖尿病视网膜病变(DR)的2型糖尿病患者的多焦视网膜电图特征.方法 经散瞳检查明确眼底无明显DR的2型糖尿病患者18例32只眼(病例组)纳入研究.其中,男性8例16只眼,女性10例16只眼;平均年龄(57.1±1.3)岁;平均糖尿病病程(10.2±0.3)年;矫正视力均≥1.0.选取同期健康体检者14例14只眼作为正常对照组.其中,男性8例8只眼,女性6例6只眼;平均年龄(53.0±5.6)岁;矫正视力均≥1.0.所有受检者均行多焦视网膜电图检查,观察1～5环N1、P1波的潜伏期和振幅密度,颞侧、鼻侧视网膜的N1、P1波潜伏期及振幅密度.结果 1、2、3环P1波潜伏期病例组分别为(48.47±2.33)、(31.19±15.53)、(15.67±5.73) ms,正常对照组分别为(40.48±3.26)、(35.88±3.64)、(38.92±3.67) ms;两组1、2、3环P1波潜伏期比较,差异有统计学意义(t=5.145、2.376、2.276,P＜0.05).颞侧视网膜P1波振幅密度病例组、正常对照组分别为(9.07±2.19)、(14.13±2.76) nV/deg2;两组颞侧视网膜P1波振幅密度比较,差异有统计学意义(t=-3.468,P＜0.05).结论 2型糖尿病患者在未出现明显DR之前P1波潜伏期即出现延长,颞侧视网膜P1波振幅密度下降.     

无视网膜病变2型糖尿病患者黄斑区血管密度及其影响因素

目的分析无视网膜病变2型糖尿病患者的黄斑区血管密度及其影响因素。方法入选140例无视网膜病变的2型糖尿病患者,应用计算机辅助软件,采用基于方向跟踪和像素卷积描述的黄斑血管分割法自动计数患者黄斑区的血管密度。根据眼底血管密度中位数分为低血管密度组和高血管密度组,比较两组患者间一般资料及生化指标的差异。另外入选了40例健康体检者为健康对照组,同时在140例患者中选择年龄、性别、身高、体质量、血压等指标均匹配的40例作为糖尿病组,比较两组患者的黄斑区血管密度水平。结果低血管密度组患者的年龄为(58.47±10.39)岁,收缩压为(135.23±12.67)mmHg(1 kPa=7.5 mmHg),均较高血管密度组[(50.86±13.86)岁、(129.73±10.41)mmHg]高,差异均有统计学意义(均为P<0.05);低血管密度组患者的体质量为(74.00±11.05)kg,红细胞计数为(4.48±0.49)×10¹²个·L^-1,红细胞压积为40.12%±4.24%,血红蛋白含量为(135.31±16.34) g·L^-1     

早期糖尿病视网膜病变视网膜血管管径变化的初步研究

目的 探讨2型糖尿病患者早期糖尿病视网膜病变(diabetic retinopathy,DR)视网膜血管管径的变化及其相关因素。设计病例对照研究。研究对象北京德胜社区糖尿病眼病随访研究的85例2型糖尿病患者(51～80岁)及年龄性别匹配的26例无糖尿病者(51～78岁)作为对照。方法 85例2型糖尿病患者根据DR情况分成两组:无DR(NDR)组(51例)、轻中度非增生性糖尿病视网膜病变(Nonproliferative diabetic retinopathy,NPDR)组(34例),26例无糖尿病者为对照组。使用计算机软件测量视网膜中央动脉管径当量(CRAE)和视网膜中央静脉管径当量(CRVE)。使用光学断层成像技术测量黄斑中心凹视网膜厚度。同时记录最佳矫正视力(BCVA)、糖尿病病程、身高、体重、糖化血红蛋白等数据。比较三组间CRAE、CRVE的差异,并分析可能的相关因素。主要指标CRAE、CRVE。结果 无糖尿病对照组右眼、NDR组右眼和NPDR组病变严重眼的CRAE分别为(151.91±13.65)μm、(156.73±11.53)μm、(154.08±9.82)μm(F=1....     

Inflammation after phacoemulsification in patients with type 2 diabetes mellitus without retinopathy: Prospective study

Purpose:To evaluate inflammation after clear corneal incision (CCI) cataract surgeryin patients with noninsulin-dependent diabetes mellitus and no retinopathy.Methods:Forty patients with diabetes and 40 age-matched controls had standardized temporal CCI cataract surgery with implantation of a foldable intraccular lens. Anterior chamber flare was evaluated in an undilated eye with a laser flare-cell meter preoperatively and 1, 3, 7, 14; and 28 days postoperatively.Results:In both groups, flare and cell values increased on the first postoperative dayand successively decreased on the following days. Flare had not recovered to preoperative values by day 28. At no time was there a significant mean difference in cell and flare between the 2 groups.Conclusion:It does not appear necessary to alter the postoperative therapeuticregimen in patients with type 2 diabetes mellitus and no retinopathy.     

Relation between increased anaerobic glycolysis and visual acuity in long-standing type 2 diabetes mellitus without retinopathy

In long-standing diabetes mellitus, blood flow to essential organs including the retina is reduced owing to macrovascular and/or microvascular changes. Poor glycolytic pathway of glucose metabolism owing to tissue hypoxia caused by ischemia at capillary bed of essential organs produces excessive lactic acid and less of adenosine triphosphate, which lead to poor cellular function. The purpose of the study was to evaluate the relationship between increased anaerobic glycolysis and visual acuity in type 2 diabetes mellitus without retinopathy. Fifty patients of type 2 diabetes mellitus of 10-12 years duration, without retinopathy, constituted the study group. The controls were 50 age-matched healthy persons without diabetes mellitus. Blood lactate level and best-corrected visual acuity (BCVA) were measured in both the groups. The mean blood lactate level was 1.05 mM/l in the control group and 2.32 mM/l in the study group. BCVA of 20/20 (log MAR 0) was seen in 48 (96%) patients of the control group and in 27 (54%) patients of the study group. BCVA of 20/30 (log MAR 0.2) was seen in 23 (46%) patients in the study group and 2 (4%) in the control group. Association of higher blood lactate level with decreased BCVA in the study group was statistically significant (P< 0.001).     

Sites of highest predictability for neurodegeneration in patients with type 2 diabetes mellitus without diabetic retinopathy

International Ophthalmology - Identifying earlier retinal thickness affection and predictability for diabetic retinal neurodegeneration (DRN) in patients with type 2 diabetes mellitus (DM2) without...     

MMP-2 gene polymorphisms in type 2 diabetes mellitus diabetic retinopathy

AIM: To study the association between polymorphisms of the MMP-2 gene and diabetic retinopathy (DR). METHODS:MMP-2 C-1306T and C-735T SNPs was genotyped by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) analysis in 151 DR patients and 150 healthy individuals served as control. RESULTS: There is no significant difference between the patient and control groups in allele or genotype distributions of MMP-2 C-735T (P=0.263 and P=0.248). Also, there is no significant difference between the patient and control in allele of MMP-2 C-1306T (P=0.03). However the result has significant deviation of C/C, C/T, T/T genotypic frequencies between the patient and control groups in MMP-2 C-1306T (P=0.008). We found that subjects with the MMP-2 C-1306T genotype had an overall 2-fold increase in the risk of developing DR [adjusted odds ratio (OR)=2.446; 95% confidence interval (CI)=1.239-4.829] compared with those with the T-1306T or C-1306T genotype. Stratification analysis showed that the MMP-2 -1306C/T and -735C/T SNPs are not associated with the development of NPDR to PDR of DR in North Chinese Han population. CONCLUSION: MMP-2 C-1306T genotypes may be associated with DR development in the Chinese population. However, there is no relationship between the MMP-2 C-735T genotypes with the development of DR.     

Detection of early diabetic change with optical coherence tomography in type 2 diabetes mellitus patients without retinopathy

PURPOSE: To detect early diabetic damage in type 2 diabetes mellitus patients with no diabetic retinopathy (NDR) using optical coherence tomography (OCT) and to evaluate OCT as a clinical test. METHODS: Thirty-two patients with NDR (n = 32) were enrolled. We examined retinal and retinal nerve fiber layer (RNFL) thickness using OCT. Two healthy normal populations were also enrolled for the retinal thickness (n = 48) and RNFL thickness (n = 34). Both OCT measurements were obtained in four areas (temporal, superior, nasal and inferior). The receiver operator characteristic (ROC) curve was generated to evaluate the predictor variables. RESULTS: Comparing the normal and NDR eyes, retinal thickness significantly increased (p = 0.03) and RNFL thickness significantly decreased (p = 0.02) in the superior areas. The area under the ROC curve was 0.65 for the superior retinal thickness and 0.63 for the superior RNFL thickness. CONCLUSIONS: Both OCT measurements can detect early retinal damage in NDR patients.     

Diabetic retinopathy and HLA antigens in type 2 diabetes mellitus

PURPOSE: Diabetic retinopathy is the most common complication of diabetes mellitus. No single predisposing factor has been identified, and genetic factors may play a role in the development of severe retinopathy. In this study, we investigated the association between diabetic retinopathy and HLA antigens in type 2 diabetes mellitus. METHODS: This study was conducted at the retina unit of the Department of Ophthalmology of Ondokuz Mayis University between October 1999 and March 2000, and included 46 diabetics with non-proliferative retinopathy and 30 with proliferative retinopathy, with 30 nondiabetic controls. HLA class I (A, B, C) antigens were studied by Terasaki's microlymphocytotoxicity test and HLA class II (DR, DQ) typing was carried out using a polymerase chain reaction-sequence specific primer. RESULTS: HLA-DR4 and DQ8 frequencies were higherin patients with non-proliferative retinopathy than those with proliferative retinopathy, and HLA-DR7 frequency was higher in patients with proliferative retinopathy than non-proliferative cases (p<0.05). No significant differences in HLA antigens were found between patient groups and controls. CONCLUSIONS: The differences in HLA antigen frequencies between patients with and without proliferative retinopathy suggest a genetic contribution to diabetic retinopathy.     

2型糖尿病发生增生性糖尿病视网膜病变的 危险因素 

目的探讨2型糖尿病发生增生性糖尿病视网膜病变( proliferative diabetic retinopathy，PDR) 的患病率和危险因素。方法对1994~2001年首次在我院糖尿病中心就诊的2型糖尿病患者 2 739例，进行眼并发症筛查中散瞳检查眼底和荧光素眼底血管造影 (fundus fluorescein angiography, FFA) 确定为糖尿病性视网膜病变（diabetic retinopathy, DR）患者的临床资料进行回顾性分析。同期检测患者的血压、空腹和餐后血糖，糖化血红蛋白（HbA1c）、血脂、肌酐和尿白蛋白含量。结果2型糖尿病DR总患病率为27.8%（761/2 739），PDR的患病率为4.2%（114/2 739），占所有DR患者的15%。PDR病变组的病程、空腹血糖、糖化血红蛋白、血压水平和尿白蛋白含量均高于对照组（P＜0.01，糖化血红蛋白低于0.05）。Logistic多元回归分析显示，影响PDR发病的危险因素是病程（r=0.15, P＜0.01）和尿白蛋白含量（r=0.08, P＜0.05）。病程为5年和5年以上的患者，并发PDR的危险因素是尿白蛋白含量和空腹血糖水平（r=0.13, P＜0.05）。进一步分析表明病程为5年以内、5~10年和大于10年的患者，PDR的患病率分别为2.3%、5.9%、12.4%。无蛋白尿、微量蛋白尿和显性蛋白尿组PDR的患病率分别为2.1%、5.3%、18.8%。结论2型糖尿病并发PDR与糖尿病病程、尿白蛋白含量、空腹血糖、糖化血红蛋白和血压水平增高有关。其中病程、尿白蛋白含量和空腹血糖水平是影响PDR发病的危险因素。(中华眼底病杂志,2003,19:338-340)     

Electrophysiological studies before and after argon-laser photocoagulation in diabetic retinopathy

50 eyes with diabetic retinopathy were studied before and after treatment with argon-laser coagulation. After treatment, decreases of the L/D ratios of the EOGs and of the amplitudes of all ERG components were found. The scotopic b waves were more involved than the photopic b waves. The peak times were hardly modified. The dark-adaptation curves were not modified. Interesting was the fact that in the pretreatment findings the EOGs were involved before the ERGs. The decreases of the L/D ratios started when avascular and ischemic zones were seen on fluorescein angiography.     

Retinal nerve fibre layer loss in patients with type 1 diabetes mellitus without retinopathy

BACKGROUND/AIM: There is evidence suggesting the occurrence of neurovisual abnormalities in patients with diabetes without retinopathy. However, the determination of abnormalities in the neural and glial elements in vivo is difficult. The aim of this study was to investigate whether a retinal nerve fibre layer (RNFL) defect (as determined by scanning laser polarimetry, SLP) is present in patients without clinical manifestations of diabetic retinopathy. METHODS: 12 patients with type 1 diabetes mellitus (DM) without retinopathy or other diabetes induced microvascular complications, underwent a complete ophthalmological examination, including automated perimetry and RNFL measurements with a nerve fibre layer analyser GDx. The data were compared with a normal control group matched for age and sex. RESULTS: The superior segment retardation in patients with diabetes was lower than in the control group, based on the superior integral (0.19 (SD 0.06) v 0.23 (0.04) mm(2), p=0.03) and the superior average (71.0 (11.05) v 84.27 (10.56) microm, p=0.007) parameters. CONCLUSION: This finding may be indicative of significant nerve fibre loss in the superior segment of the retina in patients with type 1 diabetes mellitus but without retinopathy. The meaning of intraretinal differences in RNFL retardation, indicating asymmetric NFL loss, in patients with diabetes is yet not understood.