Diabetes Mellitus (DM) is a major public health problem with significant socioeconomic implications due to its increased prevalence. Diabetic retinopathy (DR) is the most frequent complication in DM patients and remains the leading cause of legal blindness in working-age populations (Yau et al., 2012). Differentiating patients with higher vs low risk of progression to vision-threatening complications is of paramount importance for an efficient managing of the disease to prevent vision disability.

PREDICTION is a longitudinal prospective clinical study in DMT2 patients with a higher risk of progression to explore possible imaging, functional and systemic biomarkers of progression, using non-invasive methods, commonly applied in the clinical practice. Investigating the retinal vascular network (vessel density metrics with Optical Coherence Tomography Angiography) will allow a better understanding of the evolution of capillary closure and ischemia, two main risk factors for DR worsening.

Patients with Mild to Severe NPDR (ETDRS DRSS 43-53) often progress to PDR and/or CI-DME (ETDRS Report). However, it is unclear which patients in this group are likely to progress. Previous studies have shown that diabetic macular ischemia (DMI) is a risk factor for progression of DR. This study aims to correlate baseline OCTA metrics with visual function and identify risk factors for progression from NPDR to PDR and/or CI-DME.

Inclusion Criteria:

• DM type 2 according to 1985 WHO criteria.
• Age between 35 and 80 years.
• BCVA ≥ 75 letters (20 /32).
• Refraction with a spherical equivalent less than 5 Diopters.
• NPDR levels 43, 47 or 53 (based on the ETDRS criteria - 7 fields CFP).

Exclusion Criteria:

• Cataract or other eye disease that may interfere with fundus examinations.
• HBA1C ≥ 12%
• Any eye surgery within a period of 6-months before the inclusion visit date.
• Other retinal vascular disease.
• Previous laser or intravitreal injection treatment.
• Dilatation of the pupil < 5 mm.

52 eyes from 52 individuals with T2D and NPDR with ETDRS DRSS grade 43, 47 or 53, with or without previous treatment, will be included in this study, in a recruitment period of 14 months.