10-year Progression of Diabetic Retinopathy: Identification of Signs and Surrogate Outcomes (PROGRESS10)

To characterize both functionally and morphologically initial Diabetic Retinopathy (DR) stages and their progression over a period of 10 years.

Study Overview

Status

Completed

Conditions

Detailed Description

Diabetic retinopathy (DR) is the most frequent complication of diabetes mellitus and the leading cause of legal blindness in active populations of industrialized countries. Progression of DR has been up to now classified according to the ETDRS classification, based on a multicentric study that evaluated the effect of laser photocoagulation on advanced stages of DR. Although appropriate for late stages of DR, it does not grade progression well in the initial stages of the disease. Initial stages of DR require urgent characterization and their evolution should be well defined because some of the lesions are still reversible.

The early stages of DR are characterized by 4 main alterations: microaneurysms (MA) and retinal hemorrhages, represented by red dots in the fundus, blood-retinal barrier breakdown, capillary closure and damage of neuronal and glial cells of the retina. Thus, there are both microvascular changes, with endothelial cell and pericyte damage with thickening of basement membrane, and neuronal changes.

Based on previous studies, progression of DR does not occur at the same rate in all patients. Some never develop vision loss, whereas others rapidly progress to macular edema or neovascularization leading to vision loss. The understanding of the mechanisms that balance in different direction is of outmost importance. The duration of diabetes mellitus and the metabolic control are major risk factors for DR progression, but they are insufficient to explain the great variability observed in patients.

Recent data indicate that MA turnover may be an appropriate indicator of DR progression. Our research group has identified different DR progression phenotypes. Phenotype A is characterized by a low MA turnover, phenotype B characterized by increased thickness and phenotype C with predominant ischemia, with a high MA turnover. These phenotypes were defined based on MA turnover (RetmarkerDR) and on central retinal thickness (RT) measured by Optical Coherence Tomography (OCT) and the model was able to correctly identify eyes at risk of progression. 61,8-76,7% of eyes with an increase RT in the central subfield, inner and/or outer ring allowed a MA formation rate ≥ 2 and/or a MA turnover ≥ 6. More recently, some genetic variants have been linked to the different phenotypes and may explain specific progression patterns.

There is emerging evidence to suggest that retinal neurodegeneration is an early event in the pathogenesis of DR and that it could participate in the development of microvascular abnormalities. The understanding of the underlying mechanisms leading to neurodegeneration and the identification of the mediators between neurodegeneration and microangiopathy is essential.

The Investigators aim to understand the extent of these cell abnormalities in the initial stages of DR and to characterize their progression.

Analysis of retinal thickness using OCT offers non-invasive evaluation of retinal edema and can suggest an appropriate treatment target. The Investigators will use recent and innovative approaches as Spectral domain OCT (SD-OCT) with retinal layers segmentation to study neurodegenerative changes occurring in DR. OCT-Angiography and OCT-Leakage layer by layer analysis will be used for microvasculature and blood retinal barrier assessment.

Study Type

Observational

Enrollment (Actual)

119

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Liliana C Soares, MSc
  • Phone Number: +351239480151
  • Email: 4c@aibili.pt

Study Locations

      • Coimbra, Portugal, 3000-548
        • AIBILI - Association for Innovation and Biomedical Research on Light and Image

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

35 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

Male and female subjects older than 50 years-old with type 2 Diabetes mellitus and no Diabetic Retinopathy or mild Non-Proliferative Diabetic Retinopathy who have participated in the PROGRESS study (NCT03010397).

Description

Inclusion Criteria:

  • Subjects who have participated in the PROGRESS study;
  • Subjects capable of understanding the information about the study and to give their informed consent to enter the study.
  • Subjects willing and able to comply with the study

Exclusion Criteria:

- Inadequate ocular media and/ or pupil dilatation that interfere with fundus examinations

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Phenotypic classification of DR in a 5-year period
Time Frame: 5 years
Presence CME (Central Macular Edema) or PDR (Proliferative Diabetic Retinopathy)
5 years
DR severity level
Time Frame: 5 years
Early Treatment Diabetic Retinopathy Study Research Group, grading (7 fields-CFP)
5 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Retinal thickness analysis
Time Frame: 5 years
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
Time Frame: 5 years
Degree of integrity of the ellipsoid zone, assessed by SD-OCT
5 years
Choroidal thickness analysis
Time Frame: 5 years
Choroidal thickness assessed by Enhanced Depth Imaging (EDI) SD-OCT
5 years
SD- OCT- Angiography analysis
Time Frame: 5 years
Vessel analysis, assessed by SD-OCT OCT-Angiography
5 years
OCT-Leakage analysis
Time Frame: 5 years
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
Time Frame: 5 years
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
Time Frame: 5 years
P1 implicit time and P1 amplitude by ring
5 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Inês P Marques, MD, AIBILI - Association for Innovation and Biomedical Research on Light and Image

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2021

Primary Completion (Actual)

March 27, 2024

Study Completion (Actual)

March 27, 2024

Study Registration Dates

First Submitted

November 25, 2020

First Submitted That Met QC Criteria

December 1, 2020

First Posted (Actual)

December 2, 2020

Study Record Updates

Last Update Posted (Actual)

October 16, 2024

Last Update Submitted That Met QC Criteria

October 15, 2024

Last Verified

October 1, 2024

More Information

Terms related to this study

Other Study ID Numbers

  • CEC/011/20

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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