Changes in Orbital Macrovascular and Intraocular Microvascular Blood Flow After Orbital Decompression Surgery in Patients With Thyroid Eye Disease (BOD-VASC)

Evaluation of the Effect of Bilateral Balanced Orbital Decompression on Orbital, Retinal, and Choroidal Macro and Microvascular Blood Flow Parameters in Thyroid-Associated Orbitopathy

This study aims to evaluate the effects of balanced orbital decompression surgery in patients with inactive thyroid-associated orbitopathy. The study examines how the surgery influences blood flow in the orbit and microcirculation in the retina and choroid over time. Clinical findings, imaging results, and vascular changes before and after surgery will be analyzed to better understand the anatomical and functional outcomes of the procedure.

Study Overview

• Status: Completed
• Conditions: Thyroid Associated Orbitopathy
• Intervention / Treatment: Procedure: Balanced Orbital Decompression Surgery

Detailed Description

Thyroid-associated orbitopathy (TAO) is an autoimmune condition that can lead to increased orbital tissue volume, proptosis, elevated intraocular pressure, and impaired venous outflow. In the inactive phase of the disease, balanced orbital decompression (BOD) is commonly performed to relieve orbital pressure and improve both anatomical and functional outcomes.

While the clinical benefits of orbital decompression are well established, its effects on orbital blood flow and intraocular microcirculation have not been sufficiently investigated, particularly over time. This study is designed to prospectively evaluate the impact of BOD on orbital macrovascular structures and retinal-choroidal microvascular networks in patients with inactive TAO.

Patients undergoing BOD for severe proptosis will be evaluated before surgery and at multiple postoperative follow-up visits. Assessments include clinical ophthalmologic examinations, intraocular pressure measurements, and imaging-based evaluation of orbital and intraocular circulation. Orbital macrovascular parameters will be assessed using Doppler ultrasonography, while retinal and choroidal microcirculation will be analyzed using optical coherence tomography angiography (OCTA).

The study aims to characterize time-dependent vascular changes following surgery and to explore the relationship between macrovascular and microvascular responses. By providing longitudinal data, this study seeks to improve understanding of how orbital decompression influences ocular perfusion and vascular regulation, contributing to a more comprehensive evaluation of surgical outcomes in inactive TAO.

• Study Type: Interventional
• Enrollment (Actual): 15
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Pendik
    • Istanbul, Pendik, Turkey (Türkiye), 34899
      • Marmara University School of Medicine, Department of Ophthalmology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 years or older
• Diagnosis of inactive thyroid-associated orbitopathy
• Presence of moderate-to-severe proptosis with indication for surgical orbital decompression
• Planned to undergo balanced orbital decompression surgery
• Ability to provide written informed consent
• Adequate image quality for OCTA and Doppler ultrasonography assessments

Exclusion Criteria:

• Active phase thyroid-associated orbitopathy
• Thyroid dysfunction or systemic condition contraindicating general anesthesia
• Proptosis due to causes other than TAO
• History of orbital radiotherapy
• Previous orbital or intraocular surgery
• Presence of retinal or choroidal pathology affecting vascular measurements
• History of systemic vasculitis or other vascular diseases
• Diabetes mellitus or systemic hypertension
• Use of systemic immunosuppressive therapy
• Age under 18 years

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Balanced Orbital Decompression Surgery; Participants in this arm undergo balanced orbital decompression surgery performed for inactive thyroid-associated orbitopathy, with preoperative and postoperative clinical and vascular assessments.

Procedure: Balanced Orbital Decompression Surgery; Balanced orbital decompression is performed under general anesthesia using a combined medial and lateral orbital wall approach with orbital fat removal, aiming to reduce orbital pressure and improve orbital and ocular circulation in patients with inactive thyroid-associated orbitopathy.; Other Names: Combined medial and lateral orbital wall decompression with orbital fat excision

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in ophthalmic artery flow velocities	Change in peak systolic velocity and end-diastolic velocity of the ophthalmic artery, measured in cm/s, assessed by color Doppler ultrasonography before and after surgery.	Baseline and postoperative follow-up visits at 1, 3, and 6 months
Change in central retinal artery flow velocities	Change in peak systolic velocity and end-diastolic velocity of the central retinal artery, measured in cm/s, assessed by color Doppler ultrasonography before and after surgery.	Baseline and postoperative follow-up visits at 1, 3, and 6 months
Change in superior ophthalmic vein diameter	Change in superior ophthalmic vein diameter, measured in millimeters (mm), assessed by magnetic resonance imaging before and after surgery.	Baseline and postoperative follow-up visits at 1, 3, and 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in superficial capillary plexus vessel density	Change in vessel density of the superficial capillary plexus, expressed as a percentage (%), assessed by optical coherence tomography angiography before and after surgery.	Baseline and postoperative follow-up visits at 1, 3, and 6 months
Change in deep capillary plexus vessel density	Change in vessel density of the deep capillary plexus, expressed as a percentage (%), assessed by optical coherence tomography angiography before and after surgery.	Baseline and postoperative follow-up visits at 1, 3, and 6 months
Change in choriocapillaris vessel density	Change in vessel density of the choriocapillaris, expressed as a percentage (%), assessed by optical coherence tomography angiography before and after surgery.	Baseline and postoperative follow-up visits at 1, 3, and 6 months
Change in choroidal vascularity index	Change in choroidal vascularity index (unitless), assessed by optical coherence tomography before and after surgery.	Baseline and postoperative follow-up visits at 1, 3, and 6 months

Collaborators and Investigators

• Sponsor: Marmara University Pendik Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): April 4, 2023
• Primary Completion (Actual): April 30, 2024
• Study Completion (Actual): May 25, 2024

Study Registration Dates

• First Submitted: January 29, 2026
• First Submitted That Met QC Criteria: February 4, 2026
• First Posted (Actual): February 6, 2026

Study Record Updates

• Last Update Posted (Actual): February 6, 2026
• Last Update Submitted That Met QC Criteria: February 4, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Doppler Ultrasonography; OCT Angiography; Thyroid-Associated Orbitopathy; Balanced Orbital Decompression; Orbital Blood Flow; Retinal and Choroidal Microcirculation
• Other Study ID Numbers: 09.2023.423 (Registry Identifier: Marmara University School of Medicine Ethics Committee)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No