Patient-specific haemodynamic simulations have largely focused on the heart chambers or major vessels. This study presents microvascular image-based digital twins of the retinal circulation, including arterial venous and capillary flow in all three macular plexi. The uneven distribution of erythrocytes at vascular junctions was also accounted for in the in silico model. Six eyes were modelled, with twenty digital variants each to assess uncertainty in capillary architecture. The model, validated under baseline conditions, also simulates early diabetic retinopathy, revealing increased mean and variability in capillary transit times – potential indicators of retinal hypoxia. Additionally, the model predicts reduced macular perfusion in diabetes, particularly in the central macula, aligning with clinical observations of disease progression.