Effectiveness of Osteopathy as an Adjunct to Optometric Vision Therapy in Vergence Disorders (OSTEOVERG)

March 21, 2026 updated by: Jordi Zaragoza

Effectiveness of Osteopathy as an Adjunct to Optometric Vision Therapy in Subjects With Vergence Disorders: A Randomized, Double-Blind, Controlled Clinical Trial

Vergence disorders are common binocular vision conditions that can cause symptoms such as eyestrain, blurred vision, headaches, and difficulty maintaining clear vision during near tasks. These symptoms are particularly frequent in situations involving sustained near visual demand, such as prolonged use of digital devices, which is increasingly common in daily life.

Optometric vision therapy is considered the reference treatment for vergence disorders. However, not all individuals respond in the same way, and some continue to experience symptoms despite appropriate treatment. For this reason, adjunct therapeutic approaches are being explored to improve clinical outcomes.

The purpose of this study is to evaluate whether osteopathic manual therapy, when used as an adjunct to optometric vision therapy, provides additional benefits compared with vision therapy alone or vision therapy combined with a sham osteopathic intervention. This randomized, controlled, double-blind clinical trial will compare three parallel groups and will assess changes in vergence function, oculomotor performance measured by video-oculography, and symptom improvement related to vergence disorders.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Vergence disorders are binocular vision dysfunctions characterized by an impaired ability to coordinate eye movements during visual tasks, particularly at near distances. These disorders are associated with a range of symptoms, including visual discomfort, reduced visual efficiency, and decreased functional performance during sustained near-vision activities.

Optometric vision therapy is an evidence-based intervention aimed at improving vergence function and visual efficiency. Despite its effectiveness, clinical response varies among individuals, and a subset of participants may continue to experience persistent symptoms. This variability has prompted interest in adjunctive interventions that may influence neuromuscular, musculoskeletal, or functional components related to oculomotor control.

This study is designed as a randomized, controlled, double-blind clinical trial with three parallel arms. Participants diagnosed with vergence disorders will be randomly assigned to one of the following groups: (1) optometric vision therapy combined with osteopathic treatment, (2) optometric vision therapy combined with a sham osteopathic intervention, or (3) optometric vision therapy alone.

The primary objective of the study is to evaluate whether the addition of osteopathy to optometric vision therapy results in greater improvements in ocular mobility and efficiency, assessed using video-oculography systems (REMOBI and EyeSeeCam). Secondary objectives include the evaluation of symptom changes associated with vergence disorders using a validated questionnaire (CISS-V15), as well as the exploration of potential relationships between functional ocular impairment, identified somatic dysfunctions, and the anatomical distribution of reported symptoms.

Ocular motor performance will be objectively quantified through standardized vergence tasks recorded by video-oculography, including measures of reaction latency, amplitude variability, amplitude error, and neglect rate. Assessments will be conducted at baseline (pre-intervention), post-intervention (within two weeks after completion of the visual therapy program), and at follow-up time points of three and six months after the intervention.

The osteopathic intervention consists of a standardized manual treatment protocol targeting somatic dysfunctions potentially related to binocular vision and vergence function. The sham osteopathic intervention is designed to mimic the context, duration, and therapist-participant interaction of the active manual treatment without applying therapeutic osteopathic techniques, in order to preserve participant blinding.

The results of this study are expected to contribute to a better understanding of the potential role of osteopathy as an adjunctive intervention in the management of vergence disorders and to provide clinically relevant data on the relationship between somatic dysfunctions and functional visual alterations in individuals with high visual demand.

Study Type

Interventional

Enrollment (Estimated)

100

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 Contact Backup

Study Locations

  • Andorra
    • Andorra
      • Andorra la Vella, Andorra, Andorra, AD500

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

No

Description

Inclusion Criteria:

  • Adult workers (≥18 years) whose regular occupational duties involve screen-based work.
  • Presence of symptoms consistent with binocular vision dysfunction, defined as a Convergence Insufficiency Symptom Survey (CISS-V15) score ≥21 at baseline screening.

Exclusion Criteria:

  • Severe ocular disease or systemic conditions affecting vision (e.g., age-related macular degeneration, retinopathies, glaucoma, keratoconus).
  • Neurological disorders affecting ocular motility or visual function (e.g., multiple sclerosis; cranial nerve III, IV, V, or VI palsy).
  • Manifest ocular deviation not suitable for management with visual therapy.
  • Inadequate refractive correction or prism requirement >10 prism diopters (>10Δ).
  • Refractive surgery (LASIK/PRK), cataract surgery, or any ocular surgery likely to influence binocular vision within the past 6 months.
  • Use of medications known to affect ocular motility or accommodative function.
  • Cognitive impairment or neurological conditions interfering with adherence to therapy instructions.
  • Suppression or severe amblyopia limiting response to visual therapy.
  • Best-corrected visual acuity <0.5 decimal (equivalent to worse than 20/40) at distance or near.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Vision Therapy Alone
Participants receive optometric vision therapy alone, consisting of structured in-office and home-based exercises targeting vergence and binocular vision dysfunctions.
Behavioral: Optometric Vision Therapy
Structured optometric vision therapy program consisting of in-office and home-based visual exercises aimed at improving binocular vision and vergence function. The intervention is standardized across participants and delivered by qualified optometrists following a predefined protocol.
Experimental: Vision Therapy + Osteopathic Treatment
Participants receive two sessions of standardized osteopathic manual treatment separated by approximately three weeks, followed by a structured optometric vision therapy program consisting of 8 sessions delivered at a frequency of 1-2 sessions per week.
Behavioral: Optometric Vision Therapy
Structured optometric vision therapy program consisting of in-office and home-based visual exercises aimed at improving binocular vision and vergence function. The intervention is standardized across participants and delivered by qualified optometrists following a predefined protocol.
Behavioral: Osteopathic Manual Therapy
Standardized manual osteopathic intervention delivered as an adjunct to optometric vision therapy. The intervention consists of predefined manual techniques targeting somatic dysfunctions potentially related to binocular vision and vergence, applied according to a fixed protocol and session schedule. The intervention protocol is predefined and documented in detail to ensure consistency across participants.
Sham Comparator: Vision Therapy + Sham Osteopathic Intervention
Participants receive two sessions of a standardized sham osteopathic intervention separated by approximately three weeks, designed to mimic the context and duration of manual treatment without applying therapeutic techniques, followed by the same structured optometric vision therapy program (8 sessions, 1-2 sessions per week).
Behavioral: Optometric Vision Therapy
Structured optometric vision therapy program consisting of in-office and home-based visual exercises aimed at improving binocular vision and vergence function. The intervention is standardized across participants and delivered by qualified optometrists following a predefined protocol.
Behavioral: Sham Osteopathic Intervention
Sham manual intervention designed to mimic the context, duration, and therapist-participant interaction of the osteopathic intervention without applying therapeutic osteopathic techniques. The procedure is standardized and intended to maintain participant blinding.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in vergence reaction latency measured by video-oculography (REMOBI and EyeSeeCam)
Time Frame: Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Reaction latency (milliseconds) during standardized binocular convergence and divergence tasks recorded using video-oculography systems (REMOBI and EyeSeeCam). Lower latency values indicate better vergence motor performance.
Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Change in vergence amplitude variability measured by video-oculography (REMOBI and EyeSeeCam)
Time Frame: Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Variability of vergence response amplitude (%) during standardized binocular convergence and divergence tasks recorded using video-oculography systems (REMOBI and EyeSeeCam). Higher variability indicates lower stability of vergence motor control.
Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Change in vergence amplitude error measured by video-oculography (REMOBI and EyeSeeCam)
Time Frame: Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Amplitude error (%) of vergence responses relative to the target stimulus during standardized convergence and divergence tasks, automatically quantified by video-oculography systems (REMOBI and EyeSeeCam). Lower error values indicate more accurate vergence performance.
Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Change in vergence neglect rate measured by video-oculography (REMOBI and EyeSeeCam)
Time Frame: Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Neglect rate (%) defined as the proportion of trials with absent or undetected vergence response during standardized convergence and divergence tasks, recorded automatically by video-oculography systems (REMOBI and EyeSeeCam). Lower neglect rates indicate improved vergence function.
Baseline (pre-intervention); post-intervention (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Convergence Insufficiency Symptom Survey score (CISS-V15)
Time Frame: Baseline (pre-intervention); immediately after the post-intervention assessment (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.
Total score of the Convergence Insufficiency Symptom Survey (CISS-V15; range 0-60). Higher scores indicate greater symptom burden related to binocular vision dysfunction.
Baseline (pre-intervention); immediately after the post-intervention assessment (within 2 weeks after the last visual therapy session); 3 months after post-intervention assessment; 6 months after post-intervention assessment.

Collaborators and Investigators

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

Sponsor

Jordi Zaragoza

Investigators

  • Principal Investigator: JORDI Z ZARAGOZA BORT, DO, Private Practice, Andorra

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

April 1, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

February 1, 2027

Study Registration Dates

First Submitted

February 11, 2026

First Submitted That Met QC Criteria

March 1, 2026

First Posted (Actual)

March 5, 2026

Study Record Updates

Last Update Posted (Actual)

March 25, 2026

Last Update Submitted That Met QC Criteria

March 21, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • JZB-OPT-OST-01 (Other Identifier: JZaragozaBort)

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

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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