RESUMO
Diabetic retinopathy(DR)is the main cause of substantial visual impairment of occupational active individuals in the world, which has become one of the most common eye diseases that lead to irreversible visual impairment of the working population. Precise identification and accurate intervention of early DR lesions are of great significance to block or delay the development of this disease. Recent studies have shown that DR nerve injury occurs before retinal microangiopathy, it has a series of characteristic clinical manifestations, such as dark adaptation delay, contrast sensitivity and decreased tone discrimination. These characteristic clinical manifestations are key events in the early stage of DR, which are closely related to apoptosis, glial cell proliferation, oxidative stress, inflammation, excitotoxicity of glutamate and imbalance of neurotrophic factors. In this paper, the research progress of DR nerve damage and its related factors are reviewed in order to provide new ideas for the prevention and treatment of DR.
RESUMO
Objective To measure the thickness of macular inner and outer retina of chronic primary angle-closure glaucoma (CPACG) and observe its features.Methods Together 58 patients (58 eyes) including 14 patients with early CPACG,23 patients with moderate CPACG and 21 patients with severe CPACG were recruited as early CPACG group,moderate CPACG and severe CPACG group,respectively;additional 23 healthy volunteers were chosen as controls.The thickness of macular inner and outer retina at all parts were measured by RTVue-100 SD-OCT.Results The macular inner retinal thicknesses in fovea were (135.62 ± 2.96) μm,(124.21 ± 6.47) μm,(119.74 ± 10.67) μm and (94.95 ± 11.24) μm in the control group,early CPACG,moderate CPACG and severe CPACG group,respectively.The thicknesses of macular inner retina of fovea were significantly decreased in the early CPACG group,moderate CPACG group and severe CPACG group when compared with the control group (all P ＜ 0.05).There were also significant differences between early CPACG group and moderate CPACG group,severe CPACG group and moderate CPACG group and early CPACG group and severe CPACG group (all P ＜ 0.05).The thicknesses of macular outer retina of fovea,parafovea and perifovea were significantly decreased in the severe CPACG group compared with the control group (all P ＜ 0.05).Conclusion The thickness of macular inner and outer retina are decreased at all parts in patients with the severe CPACG.The macular inner retinal thickness only in the fovea is thinner in the patients with the early CPACG.
RESUMO
Objective To investigate the improvement effects of sericin on the retinal oxidative stress and micro-inflammatory state in diabetic rats.Methods A diabetic rat model was established by using high-fat and high-sugar diet and intraperitoneal injection of streptozotocin.Then 24 diabetic rats were randomly divided into sericin treatment group and diabetic model group,with 12 rats for each group,and additional 12 normal rats with the same age were collected as a normal control group.Next,the rats in the sericin treatment group received sericin solution,while the other two groups was given the same amount of normal saline once a day for 35 days.After the agent intervention,the content of malondialdehyde (MDA) and glutathione (GSH) in the retina of all rats were detected by related kits.The expressions of nuclear factor erythroid 2-related factor 2 (Nrf2),heme oxygenase 1 (HO-1),nuclear factor-κB (NF-κB) and tumor necrosis factor-α (TNF-α) protein were detected by Western blot,and finally,the retinal morphology was examined by hematoxylin-eosin staining in the 3 groups.Results The content of MDA,NF-κB and TNF-α protein expression in the sericin treatment group was (4.145 ±0.282) mmol· gprot-1,0.232 ±0.027 and 0.761 ±0.058,respectively,which was significantly lower than that in the diabetic model group [(6.813 ± 0.446) mmol · gprot-1,0.334 ± 0.024 and 0.994 ± 0.084] (all P ＜ 0.05).The content of GSH,Nrf2 and HO-1 protein expression in rat retina in the sericin treatment group was (78.518 ± 4.317) mg · gprot 1,0.591 ± 0.054 and 0.954 ± 0.091,respectively,which was significantly higher than that in the diabetic model group [(59.890 ± 5.932) mg · gprot-1,0.351 ± 0.044 and 0.585 ± 0.054] (all P ＜ 0.05).The diabetic model group presented the disorder arrangement of the neurocyte in different levels in the retina,irregular and swollen inner limiting membrane,vacuoles in the ganglion cells,but in the sericin treatment group,the morphology of retinal layers was more regular and mildly disorderly arranged.The pathological damages in the retina were alleviated significantly.Conclusion Sericin can ameliorate oxidative stress and inflammation in diabetic retina,thereby delaying the development of diabetic retinopathy.
RESUMO
Background Research demonstrated that mitochondrial pathway plays a key role in cell apoptosis.Purendan supermicropowder(PRD),a traditional Chinese medicine,may be a potentially effective therapy for neuron apoptosis in diabetic retina.Objective This study was carried out to investigate the effects of PRD on aldose reductase(AR)activity,neuron apoptosis and mitochondrial pathway in retina of diabetic rat.Methods Thirty-six clean male Wistar rats were randomly divided into normal control group,diabetes model group,PRD treatment group randomly and 12 rats for each group.The diabetes models were established by intraperitoneal injection of 25 mg/(kg · d)streptozotocin(STZ)for 3 consecutive days,and blood glucose ≥ 16.7 mmol/L was taken as the standard.PRD solution of 1.8 g/(kg · d)was lavaged in 12 models for 3 months.The eyeballs were enucleated for the preparation of retinal tissue homogenate and slice.AR activity in the retina was detected by ultraviolet spectrophotometry,and neuron apoptosis in retina was assayed by TUNEL staining.Western blot was used to assess the expressions of bcl-2,bax,cyt-c and caspase-3 protein in the retina.The use of animals followed the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Committee(Version 1988).Results Statistically significant differences were found in AR activity and AI among the normal control group,diabetic group and PRD groups(F=90.115,165.540,P＜0.01),and those of diabetic group were evidently higher than the normal control group and PRD group(P＜0.01,P＜0.01).The positive TUNEL cells mainly located in inner nuclear layer and retinal ganglion cell layer.The expressions of bax,cyt-c,caspase-3,bcl-2 and bcl-2/bax in retina were obviously different among these three groups(F =51.332,41.262,25.888,38.564,47.870,P＜0.01),and the expression of bax,cyt-c and caspase-3 protein in diabetic group evidently elevated in comparison with the normal control group and PRD group(t ＝ 10.32,11.04,6.91,P ＜ 0.01)and the expressions of bcl-2 protein and bcl-2/bax value were significantly lower in diabetic rats than in the normal control rats(t =18.05,12.23,P＜0.01).AR activity by AI of retina,the expressions of bax,cyt-c and caspase-3 proteins in retina were obviously lower in PRD group than in diabetes model rats(P ＜ 0.01),and the expression of bcl-2 protein and bcl-2/bax value were significantly higher in PRD group than in diabetes group(P＜0.01).Conclusions PRD can protect retina against the damage caused by high glucose by suppressing AR activity by downregulating the expressions of bax,cyt-c,caspase-3 proteins,increasing the expressions of bcl-2 protein in retina of diabetic rats and further inhibiting the mitochondrial pathway and reducing cell apoptosis in retina of diabetic rats.