Study On The Diagnostic Value Of Choroidal Thickness In Early Diabetic Retinopathy

Objective:To observe the changes of subfoveal choroidal thickness(SFCT)in early diabetic retinopathy(DR)with enhanced optical coherence tomography(EDI-OCT)technology,and to explore the diagnostic value of choroidal thickness(CT)in early DR.Methods:This study was a cross-sectional study.From February 2021 to July 2021,46patients(92 eyes)who were diagnosed with type 2 diabetes in the Department of Ophthalmology of the First Hospital of Shanxi Medical University and were diagnosed in a tertiary or higher hospital were selected and included in the diabetes group.14 healthy peers(28 eyes)were selected as the control group.All subjects underwent detailed ophthalmological examination and were grouped according to the examination results.The diabetes group was divided into 2 groups according to the international clinical classification of DR: 1)NDR group with 42 eyes;2)mild NPDR group with 24 eyes;3)moderate NPDR group 26 eyes in the NPDR group.The NDR group was further divided into 2 groups: 1)22 eyes in the good blood sugar control group(Hb A1c<8%);2)20eyes in the poor blood sugar control group(Hb A1 c < 8%).EDI-OCT was used to measure the subfoveal choroidal thickness in each group,and optical coherence tomography(angio-optical coherence tomography,OCTA)was used to detect the FAZ area,superficial retinal blood vessel density and perfusion density in the NDR group.By comparing SFCT and retinal parameters in NDR patients with different blood sugar control levels,the diagnostic value of SFCT in early DR was explored;changing trend.Results:(1)The SFCT of the diabetic group was 294.02±15.81 μm,and the SFCT of the normal control group was 311.07±12.74 μm.The SFCT value of the diabetic group was lower than that of the normal control group,and the difference was statistically significant(P<0.05).(2)The FAZ area,superficial retinal blood vessel density and perfusion density were 0.364±0.127,15.491±1.308,0.439±0.094 in the good blood sugar control group,and 0.362±0.111,15.320±1.442,0.428±0.076 in the poor blood sugar control group.There was no statistical significance between the two groups(P>0.05).(3)The SFCT of the good blood sugar control group was 310.90±11.59 μm,and the SFCT of the poor blood sugar control group was 297.80 ± 10.15 μm.The SFCT value of the poor blood sugar control group decreased,and the difference was statistically significant(P<0.05).(4)The SFCT values of the control group,NDR group,mild NPDR group,and moderate NPDR group were 311.07±12.74μm,304.67±12.67μm,288.79±10.22μm,281.42±12.55μm.There was a negative correlation between SFCT and the duration of diabetes in early DR patients(r=-0.985,P<0.05).With the aggravation of DR,the SFCT value gradually decreased,and there was a statistical difference between the groups(P<0.05).Conclusion:(1)The SFCT of diabetic patients is thinner than that of normal people.(2)There are choroidal changes in early DR patients before retinopathy,indicating that the changes in choroidal thickness have a good prompting value for diabetic patients who have not yet developed retinopathy.(3)The changes of SFCT in DR patients were highly correlated with the progression of DR.The more severe the DR,the thinner the subfoveal choroid.