Prediction of Progression of Retinal Ischemia in Diabetes

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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Prediction of Progression of Retinal Ischemia in Diabetes

Conditions
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Diabetic Retinopathy

Participation Criteria
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Eligibility Criteria
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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.

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

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 |
| --- | --- | --- |
| One and 2-steps change on ETDRS severity level (using standard 7-fields CFP acquisitions at 30º and in Wide-field 100º acquisitions). | Identify and characterize the progression of retinal microvascular changes (vascular occlusion) occurring in eyes with moderate to severe NPDR (ETDRS severity levels 43, 47 or 53). | 48 months | 
| Changes in Vessel density (VD) metrics (skeletonized VD, binarized VD (PD), considering macular region and midperiphery. | Explore new OCTA vascular metrics and identify which can be used as imaging biomarkers to better identify DR progression (skeletonized VD, binarized VD (PD). | 48 months | 
| Changes in geometric perfusion deficits (GPD) on the superficial and deep retinal vascular layers on SS-OCTA, considering macular region and midperiphery. | Explore new OCTA vascular metrics and identify which can be used as imaging biomarkers to better identify DR progression geometric perfusion deficits (GPD) using 3mm x 3mm and wide-field 15mm x 15mm OCTA acquisitions. | 48 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in FAZ area on OCTA |  | 48 months | 
| Changes in perimeter on OCTA. |  | 48 months | 
| Changes in circularity on OCTA. |  | 48 months | 
| Changes in GCL + IPL thickness evaluated by SD-OCT. |  | 48 months | 
| Changes in CRT and layer by layer thickness evaluated by SD-OCT. |  | 48 months | 
| Changes in BCVA (ETDRS letters chart). |  | 48 months | 
| Changes in mean luminous sensitivity in dB, evaluated by Microperimetry. |  | 48 months |