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

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

Official Title
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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).

Conditions
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Type-2 Diabetes, Diabetic Retinopathy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age over 18 years-old. Diabetes mellitus type 2 according to 1985 WHO criteria. Non-proliferative diabetic retinopathy (ETDRS level <= 35) Signs of NPDR progression based on existing clinical information: 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 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). Informed consent. Exclusion Criteria: Cataract or other eye disease that may interfere with fundus examinations Any eye surgery or treatment within a period of 6-months. Pregnant or nursing (lactating) women. Patients with chronic or severe kidney disease (glomerular filtration rate, GFR < 30 mL/min/1.73m2). Patients with acute kidney injury. Patients with known allergic or hypersensitivity reactions to gadolinium, versetamide or any of the inert ingredients. Patients around the time of liver transplantation.. Patients with implants containing metals.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Leaking Phenotype<br>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. | |
| Ischemic Phenotype<br>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. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Multimodal testing/imaging procedures - Ophthalmological Imaging | Retinal thickness measured with OCT; | 24 months | 
| Multimodal testing/imaging procedures - Ophthalmological Imaging | MA turnover computed based on CFP. | 24 months | 
| Multimodal testing/imaging procedures - Ophthalmological Imaging | Macular area with increased retinal fluorescein leakage based on RLA. | 12 months | 
| Multimodal testing/imaging procedures - Ophthalmological Imaging | Implicit time local and ring amplitudes measured with mfERG. | 12 months | 
| Multimodal testing/imaging procedures - Psychophysical Testing | Psychophysical tests for speed discrimination, achromatic contrast, and chromatic contrast. | 12 months | 
| Multimodal testing/imaging procedures - Barin Imaging | Perfusion change measured with ASL. | 12 months | 
| Multimodal testing/imaging procedures - Ophthalmological Imaging | Blood-Brain Barrier alterations assessed contrast agent with Dynamic MR. | 12 months | 
| Multimodal testing/imaging procedures - Brain Imaging | Metabolite concentrations assessed with MR Spectroscopy. | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Multimodal testing/ imaging modalities (raw data) | Raw data obtained from the different modalities (OCT,MA turnover, RLA,mfERG, psychophysical tests, ASL, Dynamic MR and MR Spectroscopy). | 24 months |