Objective To observe the influence of rAAV-mediated antisense vascular endothelial growth factor (rAAV-aVEGF165) on the expression of retinal VEGF in diabetic rats. Methods 40 Sprague-Dawley rats induced diabetic rat model by intraperitoneal injection with streptozotocin (STZ). 32 rats were involved in study besides death and blood sugar recovery in experimental process, 16 spragud-Dawleg (SD) rats were received intravitreal injection with rAAV-aVEGF165 (1010 pfu) as experimental group, another group of Sprague-Dawleg (SD) rats were injected with phosphate buffered saline (PBS) as control group. One and five month after model establishment, the expression of retinal VEGF was evaluate by immunhistochemistry and Western blot; the retinal vasular was examined by transmission electron microscopy. Results On 1 month,the expression of retinal VEGF was lowest in each group. On 5 month, the expression of retinal VEGF was decreased in experimental group which compared to control, the difference are statistically significant （t=23.87,Plt;0.01）. The transmission electron microscopy results showed that retina has no obvious chages in experimental group, however,contral group showed fragmental thickening and splitting of basement membrane, swelling and deformation of endothelia cells,fingerlike prcess into the capillary cavity,and uneven distibution of heterochromatin in pericytes. Conclusion rAAV-aVEGF165 can reduce the expression of retinal VEGF thereby preventing occurrence and development of diabetic retinopathy. rAAV is an effective vectors of eye antisense gene. （Chin J Ocul Fundus Dis，2008，24：255-258）
Macular edema is a common cause of visual loss in patients with retinal vascular diseases represented by diabetic retinopathy and retinal vein occlusion. Laser photocoagulation has been the main treatment for this kind of diseases for decades. With the advent of antagonist of vascular endothelial growth factor and dexamethasone implant, diabetic macular edema and macular edema secondary to retinal vein occlusion have been well controlled; the use of laser therapy is decreasing. However, considering possible risks and complications, lack of extended inspection of efficacy and safety of intravitreal pharmacotherapy, laser therapy cannot be replaced by now. Therefore, the efficacy and safety of laser therapy will improve by sober realization of role of photocoagulation and proper selection of treatment indication.
Objective To investigate the early influences of laser photocoagulation on macular retinal thickness in diabetic retinopathy(DR). Methods Optic coherence tomography examination was performed in 30 eyes with DR(phase Ⅲ~Ⅳ) before, and on the 3rd day and the 7th day after photocoagulation respectively. The thickness of neuroretina and pigment epithelium were measured in the areas of fovea macula and 750 μm from fovea macula. Results Three days after photocoagulation, significant thickening of neuroretina was observed in the fovea macula, which is positively related with age, fasting blood sugar and duration of DR. There was no significant changes in the thickness of pigment epithelium in macula and in the thickness of neuroretina 750 μm from fovea macula. Conclusion Significant thickening of neuroretina in fovea macula in DR early after photocoagulation reveals progressed macular edema induced by photocoagulation which is positively related with age, fasting blood sugar and duration of DR. (Chin J Ocul Fundus Dis, 2002, 18: 31-33)
Diabetic retinopathy (DR) is a major and irreversible blinding eye disease in working aged adults. Diabetic macular edema (DME) is a complication of the further development of DR, and it is one of the main causes of vision loss in DR patients. The emergence of anti-VEGF drugs has changed the treatment model of DR and DME. Firstly, for the treatment of DME, the previous focal/grid-like laser photocoagulation is converted to anti-VEGF drugs as the first-line treatment. Secondly, for the treatment of proliferative DR (PDR), panretinal photocoagulation (PRP) was the gold standard in the past, and now anti-VEGF drugs have become an alternative treatment for some PDR patients. In varying degrees of DR and DME, the option of treatment, anti-VEGF drug therapy replacing PRP, and the era of anti-VEGF drug therapy on DR treatment modes are worthy questions for consideration by clinicians. In-depth study of the clinical study of PRP and anti-VEGF drugs in the treatment of DR, the changes attention in clinical guidelines and expert consensus, the gradual establishment of treatment of DR and DME suitable, and the personalized treatment of DR patients may help improve the level of DR treatment in China.
Objective Methods Ninety male Wister rats were randomly divided into normal control group, diabetic group and FTY720 group, thirty rats in each group. Diabetes was induced by giving a single intraperitoneal injection of streptozocin. FTY720 group was administered with FTY720 at a dose of 0.3 mg/kg by oral gavage daily for 3 months after establishment of diabetes. All rats were used for experiments following intervention for 3 months in FTY720 group. Immunohistochemical staining was used to observe the expression and distribution of intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1), and the positive cells were counted. Real-time reverse transcription PCR was used to measure mRNA expression of ICAM-1 and VCAM-1. Fluorescein isothiocyanate-Concanavalin A perfusion was used to detect retinal leukocytes adhesion. Evans blue (EB) perfusion was used to analyze retinal vascular permeability. Immunofluorescence staining was used to detect retinal inflammatory cells infiltration. Results In diabetic group, both ICAM-1(t=12.81) and VCAM-1 (t=11.75) positive cells as well as their mRNA expression (t=16.14, 9.59) were increased compared with normal control group, with statistical significance (P < 0.05). In FTY720 group, both ICAM-1(t=-9.93) and VCAM-1 (t=-6.61) positive cells as well as their mRNA expression (t=-15.28, -6.10) were decreased compared with diabetic group, with statistical significance (P < 0.05). Retinal leukocytes adhesion (t=16.32) and EB permeability (t=17.83) were increased in diabetic group compared with normal control group, while they were decreased in FTY720 group compared with diabetic group(t=-9.93, -11.82),with statistical significance (P < 0.05). There were many CD45 positive leukocytes infiltration in retina of diabetic group, including CD11b positive macrophage/activated microglia, while both of them were little in FTY720 group. Conclusions FTY720 can decrease retinal leukocytes adhesion, reduce retinal vascular permeability and inflammatory cells infiltration, which is associated with down-regulation of ICAM-1 and VCAM-1.
Objective To compare the therapeutic effects of 577 nm laser and 532 nm laser panretinal photocoagulation (PRP) in the treatment of non-proliferative diabetic retinopathy (NPDR). Methods This is a prospective controlled study. A total of 23 patients (41 eyes) with clinically diagnosed severe NPDR were randomly divided into two groups including 577 nm group (11 patients, 20 eyes) and the 532 nm group (12 patients, 21 eyes). 577 nm group and 532 nm group received 3 - 4 times PRP with single-point mode. The laser energy and the number of laser spots were compared, and the laser energy density was calculated. Before treatment and 1 day, 1, 3, 6 and 12 months after treatment, the changes of best corrected visual acuity (BCVA), average threshold sensitivity, a/b-wave amplitude of flash ERG (F-ERG) in the 30° - 60° visual field, and fundus fluorescein angiography (FFA) were compared between two groups. Results The response rate was 85.0% and 23.8%, respectively in the 577 nm and 532 nm group, the difference was statistically significant (χ2=15.43，P < 0.05).Compare to the pre-treatment measurement, the average threshold sensitivity, a/b wave amplitude of F-ERG and the 30° - 60°visual field were reduced at 1 day after treatment both in the 577 nm and 532 nm group, the difference were statistically significant (F=8.68, 7.57, 4.52; P < 0.05). The average threshold sensitivity (t=2.41, 3.48, 1.23), a/b wave amplitude (a wave: t=5.82, 4.45, 7.83；b wave: t=5.40, 3.23, 4.67) of F-ERG were different between 577 nm and 532 nm group at 3 , 6 and 12 months after treatment (P < 0.05). There was no retinal neovascularization and non-perfusion region in two groups at 6 months after treatment. The average laser power were (436.25±54.65) and (446.43±35.61) mW, number of laser spots were (1952.95±299.09) and (2119.05±302.69) spots, energy density were (7.60±1.30) and (7.60±3.00) mW×ms/μm2 in the 577 nm group and 532 nm group, respectively. There was no difference in average laser power (t=1.35), number of laser spots (t=2.85) and energy density (t=1.99) between two groups (P > 0.05). Conclusion Compared with the 532 nm laser, 577 nm laser treatment has better visual outcomes for NPDR patients.