Effect Of Diabetic Course On Retinal Neurovascular Structure In Diabetic Patients Without Diabetic Retinopathy

Objective: Optical coherence tomography angiography(OCTA)is used to analyse changes in retinal neurovascular structure in no diabetic retinopathy(NDR)and the relationship with the course of diabetes.Methods: A total of 64 type 2 diabetic patients(97 eyes)diagnosed with NDR by ophthalmic examination in Qingdao Municipal Hospital Ophthalmology Department from November 2021 to December 2022 were included as the case group,and 57 healthy people(71 eyes)matched for gender and age were included as the control group.A cross-sectional study was conducted.The macular ganglion cell complex(GCC)thickness and superficial capillary plexus(SCP)density in the case group and the control group were compared,radial peripapillary capillaries(RPC),and retinal nerve fiber layer(RNFL)thickness were measured using OCTA.The differences of GCC,SCP,RPC and RNFL between the case group and the control group were compared,and the differences between GCC and SCP in the macular area,RNFL and RPC in the peripapillary area were compared.According to the duration of NDR,the case group was divided into diabetic duration.The 5-year group included 21 patients(30 eyes)with diabetes duration;19 patients(32 eyes)in 5-10 years group,diabetes duration;The10-year group consisted of 24 patients(35 eyes).To investigate whether the duration of diabetes affected the neurovascular structure of the macular area and the optic disc in NDR patients.Results:1.The GCC thickness in the experimental group was significantly thinner than that in the control group,and its local loss volume(FLV)and global loss volume(GLV)were both significantly larger than those in the control group,with statistically significant differences(P < 0.05).The SCP blood flow density in all regions of the experimental group was lower than that of the control group,and the differences were statistically significant in all quadrants except for the central macular recess(P < 0.05),and the RNFL thickness in the control group was significantly higher than that of the experimental group(P < 0.05).The RPC density in all regions of the control group was higher than that of the experimental group,but it was not statistically significant(P>0.05),and showed a trend of temporal quadrant > inferior quadrant > superior quadrant > nasal quadrant.2.There was a positive correlation between the fovea and the superior thickness,the temporal quadrant and the average thickness,the superior thickness,and the inferior thickness.There was a negative correlation between the nasal quadrant and the inferior thickness,and a positive correlation between the inferior quadrant and the superior thickness.There was a negative correlation between FLV and GLV and the fovea of SCP.The correlation between the thickness of nerve fiber layer and the density of capillary network in the corresponding quadrant of the case group was higher.3.There is a certain correlation between the neurovascular injury of NDR patients with different duration of diabetes.Through this study,the three groups of patients with different duration of diabetes were compared,the 10-year group had lower SCP density in the macular area,thinner RNFL,and longer disease duration.GCC is thicker and RPC is higher in the 5-10 years group.Therefore,for diabetic patients with a longer duration of diabetes,it is necessary to monitor the progression of retinopathy in time,so as to have a good prediction of the disease.Conclusion: 1.Neurostructural degenerative changes and reduced blood perfusion are present in the stages of no diabetic retinopathy.2.The retinal nerve structure and vascular density in NDR patients can interact with each other.3.There is a certain correlation between neurovascular injury in NDR patients with different duration of diabetes.Patients in the 10-year group had lower SCP density in the macular area,thinner RNFL,and longer disease duration.GCC is thicker and RPC is higher in the 5-10 years group.Therefore,for diabetic patients with a longer duration of diabetes,it is necessary to monitor the progression of retinopathy in time,so as to have a good prediction of the disease.