Chorioretinal Imaging, Vascular Biomarkers, and Ultra-Trail: A Pilot Study (UTMA-RETINA)

July 31, 2026 updated by: Centre Hospitalier Universitaire Dijon

Retinal and choroidal microcirculation is a relevant biomarker of systemic vascular health and lies at the heart of eye-heart interactions. Noninvasive retinal imaging, particularly OCT angiography (OCT-A), now makes it possible to examine retinal and choroidal microvascularization in vivo and to study its relationship with systemic cardiovascular and neurovascular mechanisms.

Ultra-endurance activities, such as ultra-trail races, induce significant systemic hemodynamic changes, including dehydration, variations in perfusion pressure, prolonged sympathetic activation, and redistribution of blood flow. These physiological adaptations could lead to acute and reversible changes in retinal and choroidal vascular parameters as measured by retinophotography and OCT angiography.

Several studies suggest that intense physical exercise may be accompanied by significant changes in retinal and choroidal microvascular perfusion. In particular, a significant decrease in the vascular density of the superficial retinal plexus has been observed following intense exercise in a healthy population, suggesting a transient change in retinal microcirculation. Similarly, following a marathon, a decrease in the retinal vascular density index (RVDI) has been reported, likely related to exercise-induced vasoconstriction and a transient reduction in retinal blood flow. This decrease may also be exacerbated by the drop in systemic blood pressure and the relative dehydration observed after the race. More broadly, intense endurance exercise is accompanied by cardiovascular and neurohormonal adaptations, particularly through activation of the renin-angiotensin-aldosterone system, which may modulate ocular perfusion. Scott et al. demonstrated, following a 160-km ultramarathon, significant alterations in left ventricular function and a major elevation in NT-pro-BNP, indicating systemic cardiovascular stress that was markedly greater than that observed after a standard marathon. Furthermore, a multi-omics study conducted during the Ultra-Trail du Mont-Blanc (171 km) revealed systemic oxidative stress, marked inflammation with elevated IL-6 levels, and profound metabolic changes affecting red blood cells-mechanisms recognized as being involved in microvascular dysfunction. However, these variations primarily reflect functional changes in perfusion related to hemodynamic status and autonomic tone, rather than true structural microvascular remodeling or angiogenesis. Metrics derived from OCT angiography, such as vascular density or perfusion density, are in fact sensitive to systemic variations in circulating volume, perfusion pressure, and the quality of the acquired signal.

In this context, the effects of ultra-endurance exercise on the eye remain poorly characterized. Research in this area is necessary to better understand the acute physiological adaptations of ocular microcirculation and to highlight the value of retinal imaging as a tool for cardiovascular research and prevention within an integrated eye-heart approach.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

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 Locations

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Participant who has given free, informed, and verbal consent
  • Participant of legal age
  • Participant registered for the UTMA 100 km solo ultra-trail race (for the "ultra-trail" group)
  • Active subject not exposed to intense physical exertion (>6 hours of exercise) within the 7 days prior to the enrollment visit (for the "active control" group)
  • Participant with an estimated physical activity level of 4-6 hours per week (for the "active control" group)
  • Participant agreeing to undergo ophthalmological examinations on the same schedule as the ultra-trail group (for the "active control" group)

Exclusion Criteria:

  • Myopia > 6 diopters
  • Type 1 or Type 2 diabetes
  • Protected individuals: Minors, individuals under legal protection (guardianship, conservatorship, court order), individuals unable to give informed consent
  • Individuals not enrolled in a social security program
  • Pregnant or breastfeeding women
  • Participants with a systemic or inflammatory vascular condition and cardiovascular risk
  • Participants with an ocular condition or ophthalmological history likely to impair retinal/choroidal microcirculation or the quality of imaging (vascular and degenerative macular conditions, cataracts)
  • Participants being treated with vasoconstrictors
  • Tobacco use within 4 hours prior to enrollment
  • Caffeine consumption within 1 hour prior to enrollment

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

  • Primary Purpose: Other
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Participants who ran the 100-km ultra trail
Other: Retinal imaging evaluation of both eyes without dilation before and after the Mont Afrique Ultra Trail
Retinal imaging evaluation of both eyes without dilation before and after the Mont Afrique Ultra Trail
Other: Active controls who were not exposed to intense physical exertion within the past 7 days
Other: Retinal imaging evaluation of both eyes without dilation, performed in two stages (T0 and T0+11/24H)
Retinal imaging evaluation of both eyes without dilation, performed in two stages (T0 and T0+11/24H)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference in macular vascular density of the superficial capillary plexus between the pre-race and immediate post-race examinations
Time Frame: When measuring vascular biomarkers on Day 1
Assessment of the Acute Impact of Ultra-Endurance Exercise on Retinal Microcirculation (vascular density) and choroidal microcirculation (choroidal thickness and choroidal vascular index) by comparing vascular biomarkers measured by OCT angiography in ultra-trail runners before and 15 to 60 minutes after the race.
When measuring vascular biomarkers on Day 1

Collaborators and Investigators

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

Sponsor

Centre Hospitalier Universitaire Dijon

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 (Estimated)

October 1, 2026

Primary Completion (Estimated)

February 1, 2027

Study Completion (Estimated)

February 1, 2027

Study Registration Dates

First Submitted

July 28, 2026

First Submitted That Met QC Criteria

July 31, 2026

First Posted (Actual)

August 6, 2026

Study Record Updates

Last Update Posted (Actual)

August 6, 2026

Last Update Submitted That Met QC Criteria

July 31, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ARNOULD 2026

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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