Analysis of the Choroidal Structure in the Early Stage of Type 2 Diabetic Retinopathy

BACKGROUND AND OBJECTIVE: Our aim was to evaluate the choroidal structure in the early stage of Type 2 diabetic retinopathy (DR). MATERIALS AND METHODS: The study included patients with nonproliferative diabetic retinopathy (NPDR) without edema ( n = 30, NPDR group), patients with diabetes without retinopathy ( n = 30, No DR group), and healthy subjects ( n = 33, control group). Choroidal thickness (CT), total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI) were evaluated. RESULTS: The hypertension (HT) rate was highest in patients with NPDR (63.3%), and lowest in the control group (27.3%). Subfoveal, nasal, temporal CT, TCA, and LA were thinner in patients with diabetes compared to the control group for both patients with and without HT, although not significantly. CTs, TCA, LA, and SA were lower in hypertensive patients than patients without HT in all groups. CVI and LA/SA were significantly lower in NPDR group compared to the controls for both patients with and without HT. CONCLUSION: In patients with diabetes and before clinical retinopathy develops, the thinning of the CT and CVI begins. A decrease in CVI continues as the retinopathy progresses. HT appears to be a factor that can reduce CT, TCA, LA, and SA.