Hospital based epidemiological study for diabetic retinopathy:study design and preliminary results

AIM: To describe the design and preliminary results of the hospital based epidemiological study for diabetic retinopathy (HBESDR), an ongoing epidemiological study to estimate the prevalence of diabetic retinopathy (DR) and to elucidate the clinical, anthropometric, biochemical and any other risk factors associated with diabetic retinopathy. METHODS: Totally 2000 diabetes will be recruited from the Diabetes eye clinic in the First Affiliated Hospital of China Medical University. All subjects underwent blood sugar estimation and Oral Glucose Tolerance Test to diagnose diabetes. All diabetes would undergo complete questionnaire, a comprehensive eye examination. Blood and urine would be collected for biochemical investigations. All fundus photographs for any DR will be graded. Participants who need treatment will be sent to the ophthalmic clinic and follow-up interval program for all subjects will be suggested. A computerized database is created for the records. RESULTS: To date, 1174 diabetes have been recruited, there were 350 (29.81%) DR in all diabetes, most of them were with mild non-proliferative diabetic retinopathy (NPDR) (139, 39.71%); 71 (20.29%) moderate NPDR, 66 (18.86%) severe NPDR, 74 (21.14%) proliferative diabetic retinopathy (PDR). Females, longer duration of diabetes, family history of diabetes and hypertension had a statistically significant increase in risk of any DR. CONCLUSION: The study is expected to provide an estimate of the overall prevalence of DR and the prevalence with different duration of diabetes and also a better understanding of the risk factors associated with DR.

Expressions of survivin and vascular endothelial growth factor in a Murine model of proliferative retinopathy

AIM: To examine the expression of survivin and vascular endothelial growth factor (VEGF) during the development of retinal neovascularization (NV) in a mouse model. METHODS: A well-characterized murine model of retinal NV was used to study the expression of survivin and VEGF. NV of the retina was induced in mice by exposure to 75% O-2 from postnatal day P7 to P12, followed by return to room air from P12 to P17. Expression of survivin and VEGF protein was analyzed by Immunohistochemistry. In addition, mouse model of proliferative retinopathy was analyzed by retinal fluorescein angiography and quantification analysis. RESULTS: The normal mice had both superfiekal and deep vascular layers that extended from the optic nerve to the periphery. In intraocular pressure (IOP) mice were characterized by represent a typical pattern of pathological retinal NV. There are less or little nuclei of new vessels vascular endothelial cell breaking through the inner retinal than in retinopathy of prematurity (ROP) mice, large clusters of blood vessels were adherent to the internal limiting membrane(ILM) (0.27 +/- 0.20 vs23.38 +/- 1.027, t=9.454, P <0.001). During the angiogenic period from P13 to P17, survivin and VEGF protein expression increased in experimental retinas compared with control samples (2.56 +/- 0.46 vs 3.34 +/- 0.40, t=17.43, P <0.01: 2.18 +/- 0.75 vs 4.34 +/- 0.25, t=19.61, P<0.01). Protein levels of VEGF and survivn has significantly positive correlation(P<0.05, r=0.411). CONCLUSION: Correlation was made at the protein levels of survivin expression compared with that of VEGF in a murine model of retinal NV, which suggests a temporal role for survivin and VEGF in new vessel formation in response to hypoxic stimulation.

Epidemic studies of diabetic retinopathy in China-a review

The prevalence of diabetic retinopathy (DR) is increasing dramatically as the population of patients with diabetes continues to rise. This paper wants to investigate the prevalence and risk factors of DR in China through reviewing the research from Pubmed about population-based epidemic studies. The results of observational studies suggested that the overall prevalence of DR was 1.6%-6.5% in population, 19.9%-43.1% in diabetes and 13.6% in population without diabetes, most of the DR were the mild type, macular edema and vision-threatening were 5.2% and 1.2%. The risk factors for DR were longer duration of diabetes, plasma glucose concentration, concentrations of HbA1c level, higher systolic blood pressure(BP), higher diastolic BP, male gender, rural region, and methods of diabetic treatment and so on. The prevalence of DR which was strongly related to duration of diabetes was higher with the increase of diabetes. DR would be the major leading cause of visual impairment in China, it is very important to prevent DR by early screening and any other methods.

Effect of adenovirus-mediated brain derived neurotrophic factor in early retinal neuropathy of diabetes in rats

AIMTo observe effect of adenovirus-mediated brain derived neurotrophic factor in early retinal neuropathy of diabetes in rats.

Incidence of cilioretinal arteries in Chinese Han population

AIM: To estimate the incidence of cilioretinal arteries among Han population of north China. METHODS: A cross-sectional sample of subjects aged from 20 years old to 80 years old were selected using a cluster sampling technique from Shenyang of Liaoning Province for Diabetic Eye Disease Study. Eligible subjects were recruited in the Community Health Center which took the stereo fundus photography using 45 degrees Non-Mydriatic Fundus Camera. Data were analyzed by SPSS 14.0. RESULTS: The incidence of cilioretinal arteries in 5000 eyes of 2500 subjects was determined. One, two or more cilioretinal arteries were present in 876 of all subjects and in 923 of all the eyes. Difference of presence, number and distribution of cilioretinal arteries was observed. During the subjects, the arteries occurred bilaterally in 6.9% and contributed to some portion of the temporal circulation in 78.3%, nasal circulation 14.8%, respectively. Statistical analysis indicated that there was no significant difference in incidence between men and women, left and right eyes (P>0.05). CONCLUSION: 35.0% persons have the cilioretinal arteries in Han population of north China. Men and women have an equal distribution of cilioretinal arteries.