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

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.

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 \