Association Between Autonomic Dysfunction and Choroidal Vascularity Index in Fibromyalgia

April 7, 2026 updated by: Dilara Ekici Zincirci, Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization

Association Between Autonomic Nervous System Dysfunction and Choroidal Vascularity Index (CVI) in Patients With Fibromyalgia: A Cross-Sectional Observational Case-Control Study

Fibromyalgia is frequently accompanied by autonomic nervous system dysfunction, often characterized by sympathetic predominance. Alterations in ocular microcirculation have been reported in the presence of autonomic dysfunction, including potential reductions in choroidal vascular parameters. This observational study aims to examine the association between autonomic symptom burden and the choroidal vascularity index (CVI), a quantitative marker of choroidal vascular structure derived from optical coherence tomography (OCT), in individuals with fibromyalgia compared with age- and sex-matched healthy controls.

Study Overview

Status

Completed

Conditions

Detailed Description

This is a cross-sectional, observational case-control study planned to investigate the relationship between autonomic nervous system dysfunction and choroidal vascularity index (CVI) in patients diagnosed with fibromyalgia according to the 2016 American College of Rheumatology (ACR) criteria. Participants will include adult females and males aged 18-50 years. Demographic and clinical data will be collected, including age, sex, body mass index (BMI), and disease duration.

Autonomic symptom burden will be assessed using the Composite Autonomic Symptom Score 31 (COMPASS-31). Fibromyalgia severity and its impact on daily functioning will be measured using the Revised Fibromyalgia Impact Questionnaire (FIQR). Central sensitization symptoms will be evaluated with the Central Sensitization Inventory (CSI).

All participants will undergo choroidal imaging using optical coherence tomography (OCT; Heidelberg Engineering, Heidelberg, Germany). CVI will be calculated as the ratio of luminal area to total choroidal area. To reduce operator-dependent variability, CVI quantification will be performed using an open-access artificial intelligence-assisted tool designed for choroidal layer analysis (ChoroidAI / choroidometer.com), with standardized image acquisition conditions.

Primary analyses will compare CVI between the fibromyalgia and control groups and evaluate associations between CVI and autonomic symptom burden, fibromyalgia impact, and central sensitization measures.

Study Type

Observational

Enrollment (Actual)

80

Contacts and Locations

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

Study Locations

  • Turkey (Türkiye)
    • Istanbul
      • Istanbul, Istanbul, Turkey (Türkiye)
        • Prof. Dr. Cemil Taşçıoğlu Şehir Hastanesi

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

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Adults aged 18-50 years with fibromyalgia and matched healthy controls recruited from Prof. Dr. Cemil Taşcıoğlu City Hospital in Istanbul, Turkey.

Description

Inclusion Criteria:

  • Age 18-50 years, female or male
  • Fibromyalgia group: diagnosis of fibromyalgia according to 2016 ACR criteria
  • Ability and willingness to provide written informed consent
  • Adequate ocular media clarity suitable for OCT imaging
  • Control group: age- and sex-matched healthy volunteers

Exclusion Criteria:

  • Ocular exclusions: cataract or other media opacity; glaucoma or optic nerve disease; ocular surface disorders (e.g., dry eye disease); retinal diseases (e.g., diabetic retinopathy, macular disease); ocular surgery or eye/head trauma within the last 3 months; best-corrected visual acuity < 20/20; refractive error > ±3.00 diopters; intraocular pressure > 21 mmHg; use of topical ophthalmic medications
  • Systemic/neurologic exclusions: diabetes mellitus; hypertension; hyperlipidemia; thyroid disorders; inflammatory rheumatic/autoimmune diseases; polyneuropathy or neurodegenerative disease; major depressive disorder or anxiety disorder; heavy smoking (>20 cigarettes/day); alcohol or substance dependence; excessive caffeine intake (>2.5 cups/day)

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

Cohorts and Interventions

Group / Cohort
Fibromiyalgia
Adults aged 18-50 years meeting the 2016 ACR criteria for fibromyalgia.
Healthy Controls
Age- and sex-matched healthy volunteers without fibromyalgia or major systemic/ocular disease.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Choroidal Vascularity Index (CVI)
Time Frame: Single assessment at study visit (baseline)
CVI computed from OCT-derived choroidal images as luminal area / total choroidal area.
Single assessment at study visit (baseline)
Autonomic Symptom Burden (COMPASS-31 total score)
Time Frame: Single assessment at study visit (baseline)
Single assessment at study visit (baseline)

Collaborators and Investigators

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

Sponsor

Prof. Dr. Cemil Tascıoglu Education and Research Hospital Organization

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)

October 20, 2025

Primary Completion (Actual)

December 18, 2025

Study Completion (Actual)

December 19, 2025

Study Registration Dates

First Submitted

December 25, 2025

First Submitted That Met QC Criteria

January 7, 2026

First Posted (Actual)

January 15, 2026

Study Record Updates

Last Update Posted (Actual)

April 8, 2026

Last Update Submitted That Met QC Criteria

April 7, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Fibromiyalgia2

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

De-identified individual participant data (IPD) underlying the results reported in the primary publication (including COMPASS-31, FIQR, CSI scores and OCT-derived CVI measurements) will be shared upon reasonable request. All shared data will be anonymized/de-identified and will not include any direct identifiers.

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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