Phenotypes of Nonproliferative Diabetic Retinopathy in DM 2 Patients Identified by OCT, CFP, RLA and mfERG (DIAMARKER)

Phenotypes of Nonproliferative Diabetic Retinopathy in Diabetes Type 2 Patients Identified by Optical Coherence Tomography, Colour Fundus Photography, Fluorescein Leakage and Multifocal Electrophysiology (DIAMARKER Project: Genetic Susceptibility for Multi-systemic Complications in Diabetes Type-2: New Biomarkers for Diagnostic and Therapeutic Monitoring).

To characterise phenotypes of Non Proliferative Diabetic Retinopathy (NPDR) progression using multimodal testing/imaging procedures.

Inclusion Criteria:

1. Age over 18 years-old.

2. Diabetes mellitus type 2 according to 1985 WHO criteria.

3. Non-proliferative diabetic retinopathy (ETDRS level <= 35)

4. Signs of NPDR progression based on existing clinical information:

   1. Retinal thickness (RT) increase (increase in RT above normal range as measured by OCT, considering the macular thickness normative data) in the central subfield, the inner ring and/or the outer ring (leaking phenotype); OR
   2. Neovascular disease activity as shown by microaneurysms (MA) turnover (MA formation rate >= 2, i.e. number of new MA per year) computed from CFP using the RetmarkerDR software (ischemic phenotype).

5. Informed consent.

Exclusion Criteria:

1. Cataract or other eye disease that may interfere with fundus examinations
2. Any eye surgery or treatment within a period of 6-months.
3. Pregnant or nursing (lactating) women.
4. Patients with chronic or severe kidney disease (glomerular filtration rate, GFR < 30 mL/min/1.73m2).
5. Patients with acute kidney injury.
6. Patients with known allergic or hypersensitivity reactions to gadolinium, versetamide or any of the inert ingredients.
7. Patients around the time of liver transplantation..
8. Patients with implants containing metals.