Progression of Diabetic Retinopathy. Identification of Signs and Surrogate Outcomes

Study Overview
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Brief Summary
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Progression of Diabetic Retinopathy. Identification of Signs and Surrogate outcomes (PROGRESS)

Detailed Description
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The global aim of this study is to improve the current knowledge of diabetic retinopathy (DR) progression. We aim to characterize both functionally and morphologically initial DR stages and to identify patients at risk of progression to centre involving macular oedema (CME) and/or proliferative diabetic retinopathy (PDR). We want to identify imaging patterns and characteristics that might be used as prognostic biomarkers for DR progression. For this, ischemia and blood-retinal barrier alteration will be assessed using non-invasive retinal imaging methodologies. SD-OCT with layer-by-layer segmentation will be performed. Furthermore, a state-of-the-art methodology with OCT-Angiography will be used for identification of areas of capillary drop-out and leakage areas will be identified on SD-OCT without the need of a dye injection. In a subgroup of patients we will study neurodegeneration patterns using multifocal ERG examination.

Official Title
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PROGRESS - Progression of Diabetic Retinopathy. Identification of Signs and Surrogate Outcomes

Conditions
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Diabetic Retinopathy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Type 2 diabetes mellitus according to 1985 WHO criteria Aged between 35 years and 80 at baseline in the retrospective period NPDR level < 20 (MA absent) or Mild NPDR (levels 20 to 35, based on ETDRS criteria- 7 fields CFP) at baseline BCVA ≥ 75 letters (≥ 20/32) at baseline (ETDRS charts) Informed Consent Exclusion Criteria: Inadequate ocular media and/ or pupil dilatation that interfere with fundus examinations HbA1C > 10 % at the Screening or previous 6 months in the previous prospective study

Ages Eligible for Study
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Minimum Age: 35 Years
Maximum Age: 80 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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Phenotypic classification of DR in a 5-year period | Presence CME (Central Macular Edema) or PDR (Proliferative Diabetic Retinopathy) | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| DR severity level | ETDRS grading | 5 years | 
| Retinal thickness analysis | Retinal thickness (RT) in central subfield, inner and outer rings, assessed by SD-OCT and using layer-by-layer segmentation | 5 years | 
| Ellipsoid zone analysis | Degree of integrity of the ellipsoid zone, assessed by SD-OCT | 5 years | 
| Choroidal thickness analysis | Choroidal thickness assessed by Enhanced Depth Imaging (EDI) SD-OCT | 5 years | 
| SD- OCT- Angiography analysis | Vessel analysis, assessed by SD-OCT OCT-Angiography | 5 years | 
| OCT-Leakage analysis | LOR (low optical reflectivity) ratio in central subfield, inner and outer ring for assessment of BRB breakdown, assessed by OCT-Leakage | 5 years | 
| Retinal thickness quantification | Retinal nerve fiber layer thickness (RNFL) and ganglion cells layer (GCL) + inner plexiform layer thickness (IPL) thickness, assessed by layer-by-layer SD-OCT | 5 years | 
| mfERG assessement | P1 implicit time and P1 amplitude by ring | 5 years |