Change Of Choroid Volume In Early Diabetic Retinopathy

ObjectivesTo observe the changes and structural characteristics of macular choroidal volume(MCV)in early diabetic retinopathy with enhanced depth imaging spectral domain optical coherence tomography(EDI SD-OCT),and to explore the relationship between the degree of retinopathy and the changes of macular choroidal volume in early diabetic retinopathy.MethodsFrom February 2017 to December 2017,totally 69 cases(109 eyes)diagnosed with type 2 diabetes in our hospital were selected as the diabetes group,and the average age of the group was 57.45±6.95(45-68 years).The diabetes group included44 male cases with 67 eyes and 25 female with 42 eyes.Meanwhile,16 normal healthy people(24 eyes)were selected as the normal control group,and the average age of this group was 57.81±6.85(45-68 years).All patients underwent an overall eye examination.Except for diabetic retinopathy,other retinal and choroidal fundus lesions,complicated systemic complications,ocular blood flow lesions,and patients with the history of surgery were excluded.According to DR international clinical classification standard,patients with diabetes were divided into the following groups:diabetes without DR fundus change(Non-diabetic retinopathy,NDR)group(15 cases with 26 eyes),mild non-proliferative diabetic retinopathy(Non-proliferative diabetic retinopathy,NPDR)group(18 cases with 31 eyes),moderate NPDR group(17 cases with 25 eyes)and severe NPDR group(19 cases with 27 eyes).The NPDR patients in the diabetes group were divided into two groups:NPDR combined with macular edema(NPDR+/DME+)group(28 cases with 52 eyes),and NPDR without macular edema(NPDR+/DME-)group(26 cases with 31 eyes).The EDI SD-OCT technique was used to measure the volume of macular choroid in the normal control group and the diabetes group,and the measurements were marked as MCV.SPSS 20.0 was used for statistical analysis.The mean value and standard deviation of the macular choroid volume in each group were calculated and represented as x±s.The two-sample test was applied to compare the difference of MCV between the normal control group and the diabetes group,as well as the difference of MCV between the NPDR+/DME+group and the NPDR+/DME-group.Variance analysis was used to analyze the changes of MCV in normal control group and the diabetes group.The correlation between age,duration of diabetes,fasting blood glucose,axial length and MCV were analyzed by Pearson or Spearman correlation analysis.P<0.05 was considered as statistically significant.Results1.There was no statistically significant difference in macular choroidal volume and gender,eye,axial length and fasting blood glucose between the normal control group and the diabetes group.2.The volume of macular choroid in the diabetes group and the normal control group was 7.45±1.19mm~3 and 8.98±1.20mm~3,respectively.The MCV value of the diabetes group was significantly decreased than the normal control group(P<0.05).3.The volume of choroidal choroid in the NDR group,the mild NPDR group,the moderate NPDR group and the severe NPDR group was 8.33±1.03mm~3,7.73±1.00mm~3,7.16±1.00mm~3 and 6.56±1.01mm~3,respectively.Meanwhile,the MCV of the NDR group was significantly lower than that of the normal control group(t=2.030,P<0.05).There was a negative correlation between the macular choroidal volume and the duration of diabetes in early diabetic patients.With the aggravation of diabetic retinopathy,the value of MCV decreased gradually,and the difference between each group was statistically significant(P<0.05).4.The MCV value of the NPDR+/DME+group(6.87±1.07mm~3)was statistically lower than that of the NPDR+/DME-group(7.69±0.99mm~3)(P<0.05).Conclusion1.The macular choroidal volume in diabetic patients was smaller than that in normal healthy people.2.In patients with early diabetic retinopathy,the macular choroidal volume decreased in each stage,which was also decreased with the aggravation of the disease.Choroidal structure changes have been observed in the macular region without retinopathy.3.In patients with early diabetic retinopathy combined with macular edema,the macular choroidal volume was smaller than those without edema.4.With the technique of EDI SD-OCT,the macular choroidal volume could be quantitatively observed in patients with type 2 diabetes,which is helpful for the diagnosis of early diabetic retinopathy.