Study Of Early ERG And Optic Nerve Fiber Layer Changes In Preclinical Stage Of Diabetic Retinopathy

Objective:To evaluate whether there are early retinal structural and functional impairments in patients with type 2 diabetes mellitus(T2DM)without diabetic retinopathy(NDR)using OCT,OCTA,and RETevalTM.Methods:An observational cross-sectional study.56 patients with type 2 diabetes with NDR and 56 healthy controls were selected.The medical history,color fundus photography,best corrected visual acuity(BCVA),ETDRs visual acuity chart,and Goldmann tonometry of all subjects included in this study were collected,and the HbA1c(%)values of patients with diabetes were collected.16 and 32 Tds scintillation electroretinograms(ERG)were collected using a mydriatic full field scintillation ERG recording device(RETeval TM).All subjects were subjected to HD AngioDisc[4.5]scan mode and ganglion cell complex scan mode after dilated pupils,and the retinal nerve fiber layer(RNFL)thickness and radial papillary capillaries(RPC)density in the area around the visual papilla were measured and recorded,also macular ganglion cell complex(GCC)thickness were compared and analyzed.Results:1.Compared with the control group,the hidden period of the electroretinogram in the experimental group was significantly prolonged;the RPC density and RNFL thickness of the visual papilla area were significantly reduced,and the GCC thickness of the macular area was reduced.2.In the analysis of the correlation between electroretinogram parameters and various factors in the NDR group,the longer the hidden period,the thinner the thickness of the RNFL;the greater the amplitude,the smaller the FLV(%).3.In the analysis of the correlation between diabetes course,HbA1c(%)and visual acuity with various factors,the diabetes course has a significant correlation with the retinal electrocardiographic hidden period,the density of RPC and the thickness of the RNFL;In addition,it was found that the higher content of HbA1c(%),the greater effect on the FLV(%);the RPC density above the temporal disc,the RNFL thinkness around the the nasal disc and the FLV(%)are positively correlated with vision.The regression equation was finally obtained:EDTRs=70.505+0.133(RNFL-NS)-3.422FLV,and it is statistically significant(F=9.043,P<0.001).Model R=0.573,R2=0.328,adjusted R2=0.292.Conclusions:1.The decrease in RNFL thickness and RPC density and the extension of the hidden period in diabetic patients indicate that even in the absence of visible retinopathy,the retina has begun to suffer structural and functional damage2.This indicates that reducing the thickness of RNFL may be one of the key biomarkers in the detection of NDR and may be a sensitive visual predictor in NDR subjects.