Effect Of Glycosylated Hemoglobin On Retinal Neurovascular Structure In Early Diabetic Retinopathy

Objective: To analyze the changes of retinal neurovascular structure in the early stage diabetic retinopathy(DR)and the correlation with glycosylated hemoglobin(HbA1c).Methods: The research method used in this study is a cross-sectional study.The study selected 97 eyes of 64 patients with early type 2 diabetic retinopathy(including non-diabetic retinopathy(NDR),mild non-proliferative diabetic retinopathy(mild NPDR)and moderate non-proliferative diabetic retinopathy(moderate NPDR))and71 eyes of 58 cases of normal healthy people who attended the Ophthalmology Clinic of Qingdao Municipal Hospital from November 2019 to December 2020.Optical coherence tomography vascular imaging technology was used to measure the thickness of retinal ganglion cell complex(GCC),superficial capillary plexus(SCP)density,retina nerve fiber layer(RNFL)thickness,and radial capillary plexus(RCP)density around the optic disc in diabetic patients and healthy individuals,and compare the differences between the two groups.The next step is to explore whether there is a correlation between GCC and SCP,RNFL and RCP in diabetic patients.According to the HbA1c level of diabetic patients within one month,the diabetes group was divided into 30 eyes of 18 cases with good blood sugar control(HbA1c≤7%),32 eyes of 24 cases of moderate blood sugar control group(7%-8%),and 35 eyes of 22 cases in the poorly controlled blood sugar group(HbA1c>8%),this study also explored the effect of different HbA1c levels on the neurovascular structure of early type 2 diabetes patients.All analyses were implemented using SPSS 24.0 software,and P<0.05 considered the difference to be statistically significant.Results:1.Compared with the control group,the retinal GCC thickness,SCP density,RNFL thickness,and RCP density of the diabetic group were significantly decreased.Except for the SCP density in the foveal area,the differences in the other regions were statistically significant(P <0.05)).2.Between the average thickness of GCC and SCP density of the diabetes group and the control group,except for the superior quadrant of the parafove,the nasal quadrant and the inferior quadrant,there is a correlation among the other areas,and the results are statistically significant(P <0.05).There was a high correlation between the RNFL thickness and RCP density in the two groups in the corresponding quadrants,and the results were statistically significant(P <0.05).3.The diabetic group was divided into three groups: good glycemic control group(HbA1c < 7%),moderate glycemic control group(HbA1c 7%-8%)and poor glycemic control group(HbA1c >8%).The thickness of GCC in macular area decreased with the increase of HbA1c among the three groups,and the differences were statistically significant(P < 0.05).Except temporal quadrant,nasal quadrant and inferior quadrant,there were significant differences in macular SCP density among the three groups(P <0.05).Except for the nasal quadrant,there were significant differences in RNFL density around the disc among the three groups(P < 0.05).Except for the superior part,there were significant differences in RPC density among the three groups(P < 0.05).There were significant differences in SCP density and RNFL thickness between the two groups(P<0.05).There were significant differences in SCP density,GCC thickness,RNFL thickness,and RCP density in superior quadrant and inferior quadrant between the two groups(P<0.05).There were significant differences in RNFL thickness,RCP density and SCP density in superior quadrant,inferior quadrant and nasal quadrant between moderate and poor glycemic control groups(P< 0.05)Conclusion: 1.The degenerative changes of nerve structure and the decrease of blood perfusion can be detected in the early stage of diabetic retinopathy.2.Retinal neurovascular structure damage in diabetic patients has a mutual influence,and the fovea and temporal quadrants of the macula are the most significant.3.There is a correlation between neurovascular damage between different HbA1c levels.The upper quadrant is most sensitive to retinal ischemia and hypoxia.Retinal neurovascular damage is more serious when blood sugar is poorly controlled.Early monitoring of HbA1c can play a role in the occurrence and development of retinopathy.