ABSTRACT
AlM: To measure the retinal electrical activities in patients with diabetic retinopathy ( DR ) by applying multifocal electroretinogram ( mf-ERG) and evaluate the degree of visual damage at different stages of DR METHODS:Thirty cases ( 30 eyes ) aged 50 ~70 years old, excluding other diseases, were as normal group, and 99 cases ( 99 eyes ) diagnosed with type 2 diabetes were as experiment group. The cases received mf-ERG examination in the standard state, respectively. The results were statistically analyzed RESULTS: For DR patients with early and background stage, the reaction density of mf - ERG P1 wave decreased as the disease worsened, significantly reduced in non - proliferating stage and decreased more significantly in the background of the stage Ⅲ. This showed that in the macula, electrical activity had weakened before the retina without visual or morphological changes, and with the development of the disease, the electrical activity decreased more obviously. CONCLUSlON:mf-ERG can evaluate the severity of DR, especially suit in the early and background period of DR.
ABSTRACT
Background Studieshowed thaDelta-like ligand 4 (Dll4) participatein the deveopmenof retinal celland angiogenesis.The Dll4-Notch pathway and vasculaendothelial growth facto(VEGF) are thoughto be critical mediatorof neovascularization undehypoxiconditions.The relationship between Dll4 and VEGF inovery cleaand furtheresearch ineeded.Objective Thistudy wato observe the inhibition of Dll4 on experimental retinal neovascularization and VEGF expression.MethodThe retinal neovascularization animal model wainduced by oxygen-induced retinopathy (OIR) in 5-day-old SPF SD ratby rearing the new postnatal ratwith the motherattogethein closed box with oxygen level a(80±2) ％ till 12-day-old.The ratwere then raised in normal aifo5 days.Aftethat,2.5μl (0.5 μg) of Dll4 monoclonal antibody wainjected into the mid-vitreoucavity in the righeye(Dll4 injected group) and PBwaused in the same way in the fellow eye(PBcontrol group) in the 12-day-old rats.Retinawere isolated in the 17-day-old rats,and retinal vasculamorphology waexamined by adenosine diphosphatease (ADPase) staining of retinal flatmounts,and the endotheliocyte nuclei above the internal limiting membrane were counted in the retinal tissue-slices.Reverse transcription PC(RT-PCR) waused to detecthe mRNexpression level of Dll4,VEGF,VEGF receptor-1 (VEGFR-1),VEGFR-2 and neuropilin-1 mRNin the retinas.Statistical analysiwaperformed by the paired t-test.The care and use of the animalcomplied with the Guidance Suggestion issued by the Ministry of Science and Technology of Chinin 2006.ResultThe Dll4 mRNexpression in the retin(Dll4 mRNA/β-actin mRNA) wa0.22± 0.06 and 0.98 ± 0.13 in the Dll4 injected group and the PBcontrol group,respectively,with statistically significandifference (=21.839,P =0.000).No significandifferencewere found in the expression of the VEGF mRNA,VEGFR-1 mRNand VEGFR-2 mRNin the retinabetween the two group(t=0.463,P=0.649;=1.687,P=0.109;=-1.674,P=0.111).Compared with the PBcontrol group,the expression of neuropilin-1 mRNwasignificantly elevated in the Dll4-injected group (0.73±0.08 vs.0.64±0.07) (t=-2.677,P=0.015).ADPase staining showed thathere were much more new blood vesselin the Dll4 injected group than those of the PBcontrol group.The numbeof nuclei structurally adjacento the vitreal side of the internal limiting membrane wa(63.6± 11.6)/slide in the Dll4 injected group,which wamore than thaof the PBcontrol group a(35.1±5.2)/slide (=-7.879,P =0.000).ConclusionDll4 playan essential role in the procesof pathological angiogenesiin the retina.Dll4 ithoughto be feedback regulatoof VEGFR,which participatein the procesof restraining pathological vasculogenesis.