Epigenetic modifications such as DNA methylation, histone post-translational modifications, non-coding RNA are reversible, heritable alterations which are induced by environmental stimuli. Major risk factors of diabetes and diabetic complications including hyperglycemia, oxidative stress and advanced glycation end products, can lead to abnormal epigenetic modifications in retinal vascular endothelial cells and retinal pigment epithelium cells. Epigenetic mechanisms are involved in the pathogenesis of macular edema and neovascularization of diabetic retinopathy (DR), as well as diabetic metabolic memory. The heritable nature of epigenetic marks also playsakey role in familial diabetes mellitus. Further elucidation of epigenetic mechanisms in DR can open the way for the discovery of novel therapeutic targets to prevent DR progression.
Diabetic macular edema is the leading cause of central vision loss and even blindness in diabetic retinopathy. Compared to FFA, OCT can obtain the high-resolution 3D image quickly, easily to reflect the details of the tissue and realize the quantitative measurement. As a novel technology, OCT angiography (OCTA) can display microvascular structure from different layers of retina and choroid, having its advantage of quantifying the vessel density and the lesion area. By detecting fundus morphology, quantifying and quantitating the retinal vessels and vessel density, the combination of OCT and OCTA could play a guiding role in diagnosis, classification, treatment and prognosis of diabetic macular edema.
Objective To determine the affected factors of intraorbital hemodynamic results in diabetic retinopathy (DR) and the risk factors related to the occurrence of DR. Methods Posterior ciliary artery (PCA), central retinal artery (CRA), central retinal vein (CRV), and vortex vein (VV) of 68 patients with DR were measured by color Doppler flow image (CDFI). Thirty-one hemodynamic parameters, including systolic velocity, diastolic velocity, mean velocity, resistive index, pulsatility index and accelerative velocity of ophthalmic artery (OA), and other variates (blood pressure, blood sugar, gender, age, duration of the disease, and so on) were collected and clustered in a principal components analys is following a forward, stepwise logistic regression on these components. Results Nine principal components were extracted from 37 original variates, reflecting the velocity of OA, velocity of PCA, resistance of OA, velocity of CRA,resistance of CRA, resistance of PCA, time-related factor, venous drainage factor and gender factor, respectively. In the result of logistic regression, resistance of OA, velocity of CRA, resistance of PCA, time-related factor, and venous drainage factor were the risk factors related to DR. Conclusion The first risk factor affecting DR is time, and intraorbital hemodynamic abnormity influencing the development of diabetic retinopathy may be the increase of resistance of OA, decrease of velocity of CRA, decrease of resistance of PCA, and increase of venous drainage. (Chin J Ocul Fundus Dis，2004，20：98-100)
Purpose Researching the relared risk factors of diabetic retinopathy (DR) through the epidemiological investigation. Methods Basing on a population random sampling survey and screening in 6 areas and cities of Anhui,216 diabetics were screened and they were then investigated in detail by filling in forms,measuring blood pressure,ocular examination including ophthalmoscopy,and lab examination including fasting blood glucose (FBG),blood glucose 2 hours after meal,urine albumin excretion (UAE),serum triglyceride,and cholesterol. Results The resultant date revealed that the duration of diabetes,blood pressure FBG and UAE were associated significantly with DR (Plt;0.05),and serum triglyceride and cholesterol were associated not significantly with DR(Pgt;0.05). Conclusion Long duration of diabetes,hight FBG and hight blood pressure are the important risk factors of DR,and urine albumin might forebode the occurrence of DR. (中华眼底病杂志,1998,14:119-121)
Objective To investigate the early influences of laser photocoagulation on retinal function in diabetic retinopathy(DR)． Methods The multifocal electroretinograms (MERG) of 30 eyes with DR (phase Ⅲ～Ⅳ) were tested with visual evoked response image system IV b efore,and the 3rd day and the 7th day after laser photocoagulation． Results Three days after photocoagulation, the latency of N1 prolonged in the central macula 5deg; area and superionasal quadrant．Th e response densities of N1,P1 and N2 markedly reduced, and most significant changes occurred in the central macula 5deg; area and then in the central 10deg;area． There were also differences in the changes of the amplitude of N1 and P1 in diff erent quadrants ．The changes of visual acuity were positively related to the de crease of amplitudes of N1,P1 and N2 in the macula． Conclusion The reduction of response densities in MERG reveals functional damage in diabetic retina occurring early after photocoagulation．The functional damage in macula induced indirectly by photocoagulation may explain the reduction of visual acuity after panretinal photocoagulation in some degree． (Chin J Ocul Fundus Dis, 2001,17:181-183)
OBJECTIVE:To investigate the value of psychophysical testing for the macular function in the diegnosis of diabetic retinopathy(DR). METHODS:To compare the testing results of macular light sensitivity and pattern visual evoked potential(P-VEP)of 30 eyes of 15 normal person with those of 82 eyes of 41 diabetic patients(27 eyes without DR,55 eyes with simple type DR ). RESULTS:The macular light sensitivity of diabetic patients is much lower than that of normal Control group(plt;0.05). In the diabetic group, 62.19% is abnormal in macular light sensitivity, 69.51% in P-VEP. CONCLUSION: Testing of macular light sensitivit y is helpful in finding of diabetic retinopathy and early deterioration of macular visual function in diabetics. （Chin J Ocul Fundus Dis,1996,12: 223-224）
Diabetic macular edema is the major cause of vision impairment in patients with non-proliferative diabetic retinopathy. Thickness and pathological alterations in each retina layer of diabetic macular edema (DME) patients can be performed by optical coherence tomography (OCT) device. And retinal light sensitivity at specific retinal point and fixation state can be detected by microperimetry qualitatively and quantitatively. Moreover, OCT can discover pathological anatomical changes in the retina of DME patients, thus facilitating the interpretation of the structure-function relationship in DME with combination of microperimetry results. At present, there are various therapies for DME patients, and the primary method in evaluating therapeutic efficacy is to compare the pathological changes in the retina before and after treatment by OCT. Besides, microperimetry can provide information in visual function restoration. The combined application of OCT and microperimetry has broad prospects in the diagnosis and treatment of DME patients.
Objective To study the relationship between insulinase activity of erythrocytes(EIA)and diabetic retinopathy(DR)in non insulin dependent diabetes mellitus (NIDDM) patients． Methods EIA,fasting plasma glucose (FPG),fasting plasma insulin (FINS) and glycosylated hemoglobin (HbA1c) were determined in 55 healthy controls,42 NIDDM patients with DR and 44 NIDDM patients without DR． Results EIA was lower,disease duration was longer,and FPG and HbA1c were higher in NIDDA patients with DR.EIA was decreased,duration of NIDDM was lengthened,FPG and HbA1c were increased in NIDDM patients with proliferative DR as compared with NIDDM patients with background DR．The correlation analysis showed,in NIDDM patients with DR,EIA was inversely correlated with FPG,HbA1c and duration of NIDDM． Conclusion Insulinase may play certain role in the onset and development of DR． (Chin J Ocul Fundus Dis,1998,14:132-134)
The pathogenesis of diabetic retinopathy (DR) is complex and there are many related risk factors. It is related to the course of diabetes, blood glucose, blood pressure, and blood lipids, among which the course of disease and hyperglycemia are recognized main risk factors. In addition, other factors which include heredity, gender, age, obesity, pregnancy, insulin use, can also affect the occurrence and development of DR, but there is no unified conclusion about its correlation. A comprehensive understanding of the risk factors that affect DR can provide new ideas for the prevention, diagnosis, treatment, and intervention of DR.
The prevalence of diabetes mellitus in adults of China has reached 12.8%. Diabetic retinopathy (DR) accounts for approximately 1/4-1/3 of the diabetic population. Several millions of people are estimated suffering the advanced stage of DR, including severe non-proliferative DR (NPDR), proliferative DR (PDR) and diabetic macular edema (DME), which seriously threat to the patients’ vision. On the basis of systematic prevention and control of diabetes and its complications, prevention of the moderate and high-risk NPDR from progressing to the advanced stage is the final efforts to avoid diabetic blindness. The implementation of the DR severity scale is helpful to assess the severity, risk factors for its progression, treatment efficacy and prognosis. In the eyes with vision-threatening DR, early application of biotherapy of anti-vascular endothelial growth factor can improve DR with regression of retinal neovascularization, but whether it is possible to induce capillary re-canalization in the non-perfusion area needs more investigation. Laser photocoagulation remains the mainstay treatment for non-center-involved DME and PDR.