Abstract: Diabetic choroidopathy (DC), as an important co-factor of diabetic retinopathy (DR), may accelerate the process of retinal ischemia and hypoxia due to early microcirculation disorders.The characteristics of DC include: (1) Structural alterations: Choroidal thickness (CT) exhibits significant thinning during the preclinical stages of DR, while paradoxical thickening may manifest in the proliferative phase, attributable to compensatory vasodilation mechanisms. (2) Microcirculatory abnormalities: Choriocapillaris (CC) flow deficit percentage (FD%) demonstrates significant elevation in diabetes mellitus patients without DR, and exhibits a positive correlation with DR severity progression. (3) Macrovascular and medium vessel impairment: Choroidal Vascularity Index (CVI) reduction precedes the onset of clinically detectable retinal vasculopathy, with particular predilection for the Haller's layer within the macular region. CC FD% and CVI can be used as quantitative indicatorsfor early detection of subclinical DR, while the divergent impacts of anti-vascular endothelial growth factor therapy versus panretinal laser photocoagulation on choroidal perfusion dynamics provide a basis for the formulation of individualized treatment strategies.

Key words: Diabetic choroidopathy, Choroidal capillaries, Optical coherence tomography, Optical coherence tomography angiography