Acute Effects of Cervical Manual Therapy on Eye Blood Flow

NCT07688707 | Completed

• 2 other identifiers: GOKAEK/2026-02-20SBU Van Training and Research
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

This study evaluates the acute effects of cervical manual therapy on retinal and choroidal microvascular perfusion using optical coherence tomography angiography (OCTA). In this prospective randomized sham-controlled trial, 100 patients with chronic mechanical neck pain were randomly assigned to receive either cervical high-velocity low-amplitude manipulation combined with Maitland mobilization (manual therapy group) or sham treatment. Bilateral OCTA examinations were performed at baseline and at 15, 30, 60, and 120 minutes after intervention. The primary outcome is superficial capillary plexus (SCP) foveal vessel density. Secondary outcomes include deep capillary plexus (DCP) vessel density, radial peripapillary capillary (RPC) density, subfoveal choroidal thickness, foveal avascular zone parameters, retinal nerve fiber layer thickness, ganglion cell complex thickness, and macular thickness. The study aims to determine whether cervical manual therapy produces a significant augmentation of retinal and choroidal perfusion compared with sham treatment, with peak effects expected at 60 minutes post-intervention.

Conditions

Chronic Mechanical Neck Pain

Keywords

optical coherence tomography angiography; cervical manual therapy; retinal perfusion; choroidal thickness; autonomic nervous system; randomized controlled trial

Outcome Measures

Primary Outcomes (1)

• Superficial Capillary Plexus (SCP) Foveal Vessel Density

  Change in SCP foveal vessel density measured by OCTA at 15, 30, 60, and 120 minutes post-intervention compared to baseline.

  Baseline, 15, 30, 60, 120 min

Secondary Outcomes (2)

• Deep Capillary Plexus (DCP) Foveal Vessel Density

  Baseline, 15, 30, 60, 120 min

• Deep Capillary Plexus (DCP) Parafoveal Vessel Density

  Baseline, 15, 30, 60, 120 min

Study Arms (2)

Manual Therapy Group

EXPERIMENTAL

Participants receive a single session of cervical high-velocity low-amplitude (HVLA) thrust manipulation targeting C1-C2 and C3-C4 bilaterally, supplemented by sustained Maitland grade III-IV mobilization of the mid-cervical spine. Total session duration: 15-20 minutes.

Other: Cervical Manual Therapy

Sham Control Group

SHAM COMPARATOR

Participants receive light, non-therapeutic manual contact at the same anatomical sites without joint movement, traction, or thrust (\<5 N contact force). Session duration is identical to the active intervention.

Other: Sham Treatment

Interventions

Cervical Manual Therapy OTHER

A single, standardized session consisting of cervical high-velocity low-amplitude (HVLA) thrust manipulation targeting C1-C2 and C3-C4 bilaterally, supplemented by sustained Maitland grade III-IV mobilization of the mid-cervical spine. Total session duration: 15-20 minutes. Audible cavitation is documented as a quality indicator. Participants remain seated throughout the post-intervention observation period.

Manual Therapy Group

Sham Treatment OTHER

Light, non-therapeutic manual contact at the same anatomical sites as the active intervention, without joint movement, traction, or thrust (\<5 N contact force, verified by force gauge during training). Session duration is identical to the active intervention (15-20 minutes). Participants remain seated throughout the observation window to control for postural effects on choroidal thickness.

Sham Control Group

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18-70 years
• Chronic mechanical neck pain lasting ≥3 months according to IASP criteria
• Baseline VAS pain score ≥3
• Absence of cervical radiculopathy or myelopathy
• Ability to provide informed consent and comply with study procedures
• Adequate ocular image quality for OCTA assessment

You may not qualify if:

• Previous cervical spine surgery or major cervical trauma
• Vertebrobasilar insufficiency or other contraindications to cervical manual therapy
• Active inflammatory rheumatic disease or systemic connective tissue disorder
• Known retinal or optic nerve disease that may affect OCTA measurements (glaucoma, diabetic retinopathy, age-related macular degeneration, optic neuritis, etc.)
• Diabetes mellitus with end-organ complications or uncontrolled systemic hypertension (\>160/100 mmHg)
• Refractive error \> ±6.0 D spherical equivalent or astigmatism \>3.0 D
• Intraocular pressure \>21 mmHg
• Previous ocular surgery, ocular trauma, or retinal laser treatment
• Media opacity preventing adequate OCTA image acquisition
• Pregnancy or lactation
• Participation in another interventional clinical study within the previous 30 days

Sponsors & Collaborators

• Yuzuncu Yil University: lead

Study Sites (1)

SBU Van Training and Research Hospital

Van, 65000, Turkey (Türkiye)

Location

Related Publications (1)

• Evcimen Y, Başkan B, Öztürk S. Acute Effects of Cervical Manual Therapy on Retinal and Choroidal Perfusion Assessed by Optical Coherence Tomography Angiography: A Prospective Randomized Sham-Controlled Trial. [Manuscript]. SBU Van Training and Research Hospital, Van, Turkey; 2026. doi:10.5281/zenodo.20788573.

  RESULT

Related Links

• Link to the dataset and supporting information for this study on Zenodo.

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The treating physiotherapist could not be blinded. Participants were blinded to group allocation. OCTA acquisition was performed by a technician blinded to group assignment. Image analysis was performed by an investigator masked to both group allocation and temporal sequence using randomized alphanumeric file codes.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Participants are randomly assigned in a 1:1 ratio to receive either cervical manual therapy or sham treatment.

Study Record Dates

• First Submitted: June 30, 2026
• First Posted: July 7, 2026
• Study Start: February 23, 2026
• Primary Completion: May 25, 2026
• Study Completion: May 26, 2026
• Last Updated: July 7, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE
• Time Frame: Data are available immediately upon publication (June 21, 2026) and will remain accessible indefinitely in the Zenodo repository.
• Access Criteria: The datasets are publicly accessible without restrictions. Anyone can access the de-identified individual participant data and supporting documents via the Zenodo repository without requiring additional permissions or data use agreements. The analysis scripts are available from the corresponding author upon reasonable request.

Locations

TU (1)