Endo H, et al. - In this retrospective observational study, researchers assessed 105 subjects to analyze the association between the choroidal structure of diabetic patients without diabetic retinopathy (DR) and also to examine the duration of diabetes. No significant variations were noticed in areas of the total choroid and lumina/stroma or central choroidal thickness (CCT) between control and diabetes mellitus (DM) groups. Conversely, they observed significantly lower lumina/total choroidal (L/C) ratio in diabetic eyes vs control eyes. They also noted the L/C ratio significantly lower in the long duration group vs the short duration group. However, no significant difference in the areas or CCT between short and long duration groups was reported. They suggested the L/C ratio an efficient biomarker in monitoring choroidal vascular disorders in diabetic eyes without DR.