Relationship between choroidal structure and duration of diabetes

BackgroundThe aim of this study was to evaluate the relationship between the choroidal structure of diabetic patients without diabetic retinopathy (DR) and duration of diabetes.MethodsThis study is a retrospective observational study in diabetic patients without DR. Eyes with diabetes mellitus (DM) (n=105) were divided into two groups based on the duration: long duration group (over 10years, n=31) and short duration group (less than 10years, n=74). One hundred seventeen eyes of non-diabetic patients were used as control group. All patients underwent enhanced depth imaging optical coherence tomography, and the choroidal structure was analyzed using a binarization method.ResultsThere was no significant difference in areas of total choroid and lumina/stroma or central choroidal thickness (CCT) between control and DM groups. In contrast, lumina/total choroidal (L/C) ratio was significantly lower in diabetic eyes than in control eyes (P=0.02). Although there was no significant difference in the areas or CCT between short and long duration groups, L/C ratio was significantly lower in the long duration group than in the short duration group (P=0.03).ConclusionsThe current study suggests that choroidal vasculature is involved in the diabetic eyes and that the choroidal structure has changed with duration of diabetes. Our study points out that L/C ratio is a new potential biomarker in monitoring choroidal vascular disorders in diabetic eyes without DR.