| Objective:Using optical coherence tomography angiography(OCTA)to observe the changes of macular ganglion cell complex(GCC)and macular microvascular parameters in non-proliferative diabetic retinopathy(NPDR),and to explore the correlation between the them.Methods: This study included 80 eyes of 49 patients who were diagnosed with type II DM in the ophthalmology clinic from January 2020 to October 2020,and were divided into non diabetic retinopathy(NDR)group and NPDR group.At the same time,20 eyes of 12 healthy subjects were collected as the control group.Subjects received medical history collection,basic ophthalmological examination.OCTA was used to detect GCC thickness,focal loss volume(FLV)and global loss volume(GLV),the vessel density of superficial capillary plexus(SCP)and deep capillary plexus(DCP),and the superficial foveal avascular zone(FAZ)area,.Furthermore,to analyze the correlation between GCC parameters and SCP vessel density.Results: Compared with the control group,the thickness of each area of GCC in the NDR group and the NPDR group was significantly thinner(P<0.05).Compared with the NDR group,the average thickness of GCC and the upper area thickness of GCC increased in the NPDR group,and the lower area thickness of GCC decreased,however the difference was not significant(P=0.581,P=0.085,P=0.451).FLV gradually increased with the disease,and the differences between the three groups and pairwise comparisons were statistically significant(P<0.05).Compared with the control group,the GLV of the NDR group and the NPDR group increased significantly(P<0.05).The GLV of the NPDR group increased compared to the NDR group,but the difference was not significant(P=0.991).The average,upper and lower blood vessel density of SCP and DCP among the three groups gradually decreased with the disease,and the FAZ area gradually increased with the disease.There were statistically significant differences among the three groups and pairwise comparisons(P<0.05).The vessel density in each area of SCP is significantly positively correlated with the thickness of the corresponding area of GCC,and significantly negatively correlated with FLV and GLV.Conclusion: GCC has been significantly thinned in the early stage of DR,and RGC loss has occurred.FLV increases with the progress of the disease,which can reflect the degree of focal damage of DR,it is one of the best parameters for effectively identifying and distinguishing the severity of DR.GLV increased significantly.The vessel density in each area of SCP is positively correlated with the thickness of the corresponding GCC area,and significantly negatively correlated with FLV and GLV.OCTA can better dynamically monitor the microvascular changes and nerve changes in DR patients.For NPDR patients and DM patients without fundus changes clinicaly,the use of OCTA to observe fundus nerve and microvascular changes is of great significance for the diagnosis,treatment and prevention of DR. |
