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.
Objective To explore the effect of oxygen inhalation on the retinae of newborn rats and its mechanism.Methods We mimicked the retinopathy of prematurity(ROP) by putting the newborn rats in high concentrated oxygen. One-day old rats were put into the oxygen box with the oxygen concentration of 80% for continuous 7 days; then in air condition for 7 days. The arterial blood oxygen pressure, retinal superoxide dismutase (SOD), and malondialdehyde (MDA) of the rats (1,2,4,7,8,9,11,14 days old) were examined. The diameter of retinal vessels′main branch and the coverage rate of peripheral vessels were measured in 7- and 14-day-old rats by ink perfusion. The retinal neovascularization of rats (8,9,11, 14 days old) were observed by HE staining. The rats of the same age fed in air condition were in the control group.Results The differential pressures of blood oxygen of rats (1,2,4,7 days old) in study group were significantly higher than those in the control group (P＜0.01), while the differential pressures of blood oxygen of rats (8,9,11,14 days old) in study group were lower than those in the control group (P＞0.05). The contents of SOD of the retinae in the rats ( 1,2,4,7,8 days old) were significantly lower than those in the control group(P＜0.01, P＜0.05 ), while the contents of MDA were significantly higher than those in the control group (P＜0.01,P＜0.05). The diameter of retinal vessels′main branch in 7-day rats was 75% of the control group, and the coverage rate of peripheral vessels was 22% of the control group; and was 61% and 73% respectively in 14-day-old rats. The neovascularization could be seen in 16.7% of the rats in the study group and nought in the control group.Conclusion The damage of free radical of the retina in high concentrated oxygen and hypoxia situation after oxygen supply may be one of the most important mechanism of ROP. (Chin J Ocul Fundus Dis，2003，19：269-332)
Purpose To clarify the relationship between diabetic retinopathy (DR) and maculopathy (DM) and explore the clinical implication of independent graduation of DM. Methods Fundus fluorescein angiography and routine ophthalmological examination were performed on 582 cases of diabetes.Their ocular fundi and macular impairments were graded. Results In general,the severity of diabetic macular impairment was accompanied by retinal involvement,but discrepancy existed between DM and DR.Degree I DM occurred in 5.4% (16/294) among cases without DR,in stage IV DR,degree Ⅲ DM accounted for the most part ,54.5% (116/213).There were still 5.1% (2/39) cases without DM in stage Ⅴ DR. Conclusion The degree of the macular lesions in DM is often not in parallel with the gradation of general affections in retinal tissue other than in macular region in DR,therefore,independentg radation of diabetic maculopathy has its clinical significance for choosing the optimal period of treating maculopathy and preserving the macular function. (Chin J Ocul Fundus Dis,2000,16:153-154)
Purpose To observe the color motion perception of patients with diabetic retinopathy (DR) in very early stage and find a good way to diagnose early DR in time． Methods The motion perceptions of patients with early DR and normal subjects were tested by using equiluminant moving chromatic grating and moving luminance grating generated on VGA monitor in a PC compatible computer and the results were compared with those of electroretinogram(ERG),oscillatory potentials(OPs) and color perception． Results When the two gratings were of equal spatial frequency and equal time frequency,the normal subjects judged that chromatic grating moved faster than luminance grating．Very signifincant differences were detected between blue/yellow grating and black/white grating while the luminance contrast of was 80% and the velocity was 20.2 mm/s or 14.3mm/s(Plt;0.01).The abnormal ratio of color motion perception(69.2%)was higher than that of color vision(43.6%) and ERG OPs(48.9%) when the luminance contrast of black/white grating was 80% and the velocity was 20.2mm/s. Conclusion The test of color motion perception provides new method for diagnosing early DR. (Chin J Ocul Fundus Dis,1998,14:135-138)
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)
Objective To observe the effect of high glucose on the expression of activating transcription factor 4 (ATF4) in cultured retinal Muuml;ller glia cells. Methods The retinal tissue of Sprague-Dawley (SD) rats was collected, and Muuml;ller cells were isolated and cultured. The glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS) of Muuml;ller cells were identified by streptavidin-biotin-peroxidase complex. Cultured rat Muuml;ller cells were divided into control group (5.5 mmol/L glucose), group A (20 mmol/L glucose), group B (30 mmol/L glucose) and group C (40 mmol/L glucose). ATF4 protein expressions in Muuml;ller cells of four groups were measured by Western blot four days after cultured. Results GFAP and GS expressed in more than 95% of Muuml;ller cells. Over 95% of Muuml;ller cells of group A, B and C were positive for GFAP and GS. Western blots indicated that ATF4 protein in group A, B and C increased obviously compared with the control group (q=0.293, 0.754,0.484;P＜0.05). Conclusion High glucose can increase the expression of ATF4 protein and cause endoplasmic reticulum stress in retinal Muuml;ller glia cells in vitro.
Diabetic retinopathy is a serious complication of diabetes and is the leading cause of blindness in people with diabetes. At present, there are many views on the pathogenesis of diabetic retinopathy, including the changes of retinal microenvironment caused by high glucose, the formation of advanced glycation end products, oxidative stress injury, inflammatory reaction and angiogenesis factor. These mechanisms produce a common pathway that leads to retinal degeneration and microvascular injury in the retina. In recent years, cell regeneration therapy plays an increasingly important role in the process of repairing diseases. Different types of stem cells have neurological and vascular protection for the retina, but the focus of the target is different. It has been reported that stem cells can regulate the retinal microenvironment and protect the retinal nerve cells by paracrine production, and can also reduce immune damage through potential immunoregulation, and can also differentiate into damaged cells by regenerative function. Combined with the above characteristics, stem cells show the potential for the repair of diabetic retinopathy, this stem cell-based regenerative therapy for clinical application provides a pre-based evident. However, in the process of stem cell transplantation, homogeneity of stem cells, cell delivery, effective homing and transplantation to damaged tissue is still a problem of cell therapy.
Objective To observe the short-term effect of changing the sequence of PRP and MLP on the pre-proliferative or proliferative diabetic retinopathy patients with clinical significant macular edema (CSEM). Methods Sixty-three consecutive pre-proliferative or proliferative diabetic retinopathy outpatients (103 eyes) with clinical significant macular edema were selected and divided into two groups: 54 eyes in patients of group A accepted MLP one month prior to PRP and 49 eyes in patients of group B accepted the photocoagulative therapies in a contrary sequence. All the patients were followed up for 3 to 13 months and visual acuity. Light sensitivity of 5deg;macular threshold, and FFA were performed pre- and post-photocoagution. Results The improvement of visual acuity was found to be better in group A than that of group B (Plt;0.01) 2 months after the therapy, since then, there was no significant defference (Pgt;0.05) in both groups. Three and 4 months after the treatment, there was no significant difference in change of light sensitivity of 5deg;macular threshold in both groups. The macular leakages of 59 eyes, 32 ingroup A and 27 in group B, were well controlled. Conclusion Among the pre-proliferative or proliferative diabetic retinopathy patients with CSEM, visual acuity of those who accept MLP prior to PRP more rapidly than those who accept contrary sequence of photocoagulation, but the changing of therapeutic sequence might have no dramatic influence on light sensilivity of 5deg;macular threshold. (Chin J Ocul Fundus Dis,2000,16:150-152)
Objective To observe the functional and morphological changes of macular after panretinal photocoagulation（PRP）in the patients with diabetic retinopathy（DR）.Methods A total of 57 eyes of 34 patients with DR undergoing PRP were enrolled in this prospective and self-reflection study. Comparatively analyze the changes of the best visual acuity（BCVA）, optical coherence tomography (OCT) and multi-focal electroretinography (mfERG) before PRP,20 days, 3 months and more than 9 months after PRP. Statistical analyses were performed by wilcoxon, chisquare, Dunnett-t, LSD-t tests and spearman related analyses. The changes of macular function and foveal retinal thickness before and after PRP were comparatively analyzed.Results BCVA of all patients reduced at 9 months after PRP（P=0.022）.The amplitude density of mfERG P1 of ring 2 decreased at 20 days after PRP（P=0.039）,then recovered at 3 months and decreased again at 9 months（P=0.014）.The amplitude density of mfERG P1 of ring 3-5 decreased at 20 days,3 months and more than 9 months after PRP（20 days: ring 3: P=0.000,ring 4: P=0.001, ring 5: P=0.000；3 months: ring 3:P=0.000, ring 4: P=0.006, ring 5: P=0.001; more than 9 months: ring 3: P=0.000,ring 4: P=0.000, ring 5: P=0.000）. The amplitude density of mfERG P1 of ring 1 was significantly lower at 9 months after PRP（P=0.050）. The foveal retinal thickness increased at 20 days after PRP(P=0.007), then recovered at 3 months or later. Cystoid macular degeneration was found in 6 eyes(10.5%) at 20 days after PRP.Conclusions After the treatment of PRP, there were some extend reduction of the macular function, a transient increase on foveal retinal thickness. Combined mfERG and OCT can be a comprehensively and objectively assessment of macular function and morphology.