Longitudinal Observational Study of Diabetic Retinopathy Progression in Type 2 Diabetes Patients

Inclusion Criteria: * Type 2 diabetes mellitus (T2D) according to 1985 World Health Organization (WHO) criteria. * Age between 35 and 80 years. * Best-corrected visual acuity (BCVA) ≥ 69 letters (20/40). * Refraction with a spherical equivalent less than 5 diopters. * Non-proliferative diabetic retinopathy (NPDR; DRSS levels 43, 47, 53) or mild proliferative diabetic retinopathy (PDR; DRSS level 61: Neovascularization Elsewhere (NVE) \< ½ disc area in ≥ 1 quadrant, no Neovascularization of the Disc (NVD), no vitreous or sub-hyaloid hemorrhage), in which panretinal photocoagulation (PRP) and/or intravitreal anti-VEGF treatment can safely be deferred for at least 6 months, based on consensus between patient and investigator - using ETDRS criteria, 7-field equivalent area on ultra-widefield fundus imaging. * Ability to understand and sign the written Informed Consent Form (ICF). Exclusion Criteria: * Central subfield thickness (CST) \> 400 μm (fluid allowed if CST ≤ 400 μm and foveal contour is normal, as determined by the Central Reading Centre, and treatment is not immediately required). * Any sign of retinal fibrovascular proliferation. * Uncontrolled glaucoma (intraocular pressure \> 25 mmHg regardless of concomitant IOP-lowering medications) or neovascular glaucoma. * Any sign of iris neovascularization, vitreous, or pre-retinal hemorrhage. * Other retinal vascular diseases (ocular ischemic syndrome, retinal arterial or venous occlusion, exudative age-related macular deg…