Inclusion Criteria:  age older than 50 years diagnosis of previous type 2 diabetes mellitus absence of signs of diabetic retinopathy absence of previous ocular surgery, congenital eye disease, high myopia (>6 dioptres), actual or previous diagnosis of glaucoma, optic disc anomaly, macular or vitreoretinal diseases. absence of significant lens opacities, low-quality OCT and OCT-A images  Exclusion Criteria:  age younger than 50 years absence of previous diagnosis of type 2 diabetes mellitus presence of signs of diabetic retinopathy presence of previous ocular surgery, congenital eye disease, high myopia (>6 dioptres), actual or previous diagnosis of glaucoma, optic disc anomaly, macular or vitreoretinal diseases. presence of significant lens opacities, low-quality OCT and OCT-A images.