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IRCT20251122068072N1 IRCT 2025-11-26 Iran University of Medical Sciences The effect of vision therapy compared with usual care on vision, fear of falling, and quality of life in people with Parkinson’s disease VTPD Comparison of a structured vision-therapy program versus usual care on visual performance, fear of falling, and quality of life in individuals with idiopathic Parkinson’s disease: a randomized clinical trial 2026-09-22 anticipated 30 Pending https://irct.ir/trial/87652 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Other design features: The study is a randomized controlled trial (RCT) with parallel groups. Participants are allocated to intervention or control groups using 1:1 block randomization with sealed opaque envelopes. The study is single-blind: participants are unaware of their group allocation, and outcome assessments are conducted by independent blinded assessors. The intervention group receives vision therapy (VT), while the control group receives only general health information (inactive control). Assessments include vision-related quality of life, fear of falling, visual and cognitive performance, mobility and functional balance, contrast sensitivity, stereopsis, near point of convergence, fusional vergence, and other relevant visual tests. A pilot study will be conducted to verify assessor agreement and to fine-tune the protocol, Randomization description: After screening and confirming eligibility, participants will be assigned to either the intervention or control group using 1:1 block randomization. Sealed, opaque envelopes will be used to ensure allocation concealment for both participants and researchers. Block sizes and sequences will be generated by a randomization software. Optometrists assigned to the intervention and control groups will be different and trained by the research team to ensure standardized administration and minimize bias. To ensure reliability of assessments, the agreement between these evaluators will be tested in a pilot study of ten participants, Blinding description: This study is a participant-blinded randomized controlled trial. Due to the use of a placebo vision-therapy protocol in the control group, participants will remain blinded to their group allocation. The placebo exercises will be designed to mimic the structure, duration, and therapist–participant interaction of the active vision-therapy sessions, ensuring that participants cannot distinguish between the intervention and control conditions. Outcome assessors will not be blinded to group allocation due to the nature of the visual, functional, and mobility assessments, which require detailed clinical judgment and cannot feasibly be conducted under blinded conditions. Randomization will be performed using a block randomization method with allocation concealment ensured through sequentially numbered, opaque, sealed envelopes (SNOSE). The data analyst will remain blinded to the group assignments, and all datasets will be coded prior to statistical analysis. Accordingly, participants will be blinded to their assigned group, while outcome assessors will not be blinded. The trial will therefore operate as a participant-blinded randomized controlled study. 3 Idiopathic Parkinson’s disease. Intervention 1: Intervention Group: Structured Vision-Therapy ProgramParticipants in this group will receive a structured vision-therapy program consisting of evidence-based exercises derived from the Delphi phase of the study. The intervention includes standardized exercises targeting convergence, fusional vergence ranges, accommodative function, saccades, and smooth pursuits.The program will be delivered by trained optometrists. The duration (expected 8–12 weeks), frequency (2–3 sessions per week), and session length (30–45 minutes) will be finalized after the pilot study. Exercises progress from basic to advanced levels and include both in-clinic and home-based components.Monitoring will be conducted using structured checklists during each phase: (1) basic training, (2) advanced/extended exercises with compliance monitoring, and (3) review and consolidation of learned skills. Intervention 2: Control Group: General Health Education + Placebo Vision TherapyParticipants in the control group will not receive active vision therapy. However, to maintain participant blinding, a placebo vision-therapy protocol will be administered. This placebo protocol consists of a set of exercises designed to resemble the structure, duration, and therapist–participant interaction of the active vision-therapy sessions, but without the therapeutic components expected to produce clinical improvement.In addition to the placebo intervention, the control group will receive a weekly standardized educational package containing information relevant to general health in individuals with Parkinson’s disease, including recommendations on nutrition, safe and light physical activity, environmental safety, and general symptom management.The number of sessions, their duration, and the content of the placebo exercises and educational materials will be matched to the intervention group and finalized based on the findings of the pilot study to ensure equal attention and contact time across both groups. Yes - There is a plan to make this available What will be shared: Title: Data and documents from the clinical trial on vision therapy in patients with idiopathic Parkinson’s disease Details: The dataset includes de-identified participant data, baseline and outcome measures, and study-related documents such as protocol, informed consent forms, and statistical analysis plan. Data may be shared for scientific research purposes upon reasonable request and approval by the ethics committee. When: The data and study-related documents will become available after publication of the primary results and will remain accessible for up to 5 years. To whom: Data and study-related documents will be available to researchers who submit a reasonable request for scientific purposes and receive approval from the principal investigator and the ethics committee. Conditions: Data and study-related documents may be used only for scientific research purposes, with appropriate ethical approval, and in accordance with the conditions set by the principal investigator and the ethics committee. Where to obtain: Data and study-related documents can be obtained by contacting the principal investigator of the study. Contact details will be provided in the study registry. How to obtain: Researchers must submit a reasonable request specifying the purpose of data use. The request will be reviewed and approved by the principal investigator and the ethics committee. Upon approval, the requested de-identified data and documents will be shared under the agreed conditions. Comments:
public Faezeh Fayaz
Shah-Nazari
Tehran Iran (Islamic Republic of) ۱۳۴۸۷ ۱۵۴۵۹ +98 21 2222 8051 faezehfayaz.opt@gmail.com Iran University of Medical Sciences scientific Faezeh Fayaz
Shah-Nazari
Tehran Iran (Islamic Republic of) ۱۳۴۸۷ ۱۵۴۵۹ +98 21 2222 8051 faezehfayaz.opt@gmail.com Iran University of Medical Sciences Iran (Islamic Republic of) Age between 30 and 75 years. Diagnosis of idiopathic Parkinson’s disease confirmed by a neurologist based on the UK Brain Bank Criteria. Disease severity between stages 1 and 3 on the Hoehn and Yahr scale. Adequate cognitive function defined as a score of 24 or higher on the MoCA test and 82 or higher on the PD-CRS test. Ability to read and write in Persian Absence of young-onset Parkinson’s disease (onset before the age of 21 years). No substance abuse according to the patient and family reports. No other major neurological disorders based on neurologist evaluation. Best corrected visual acuity of 20/40 or better in each eye. Presence of binocular vision dysfunction, including a CISS score greater than 21, near point of convergence exceeding 8 centimeters, and other indicators of binocular vision anomalies if applicable. Stable dosage of antiparkinsonian medications throughout the study period. No severe anxiety or depression based on the HADS questionnaire (scores below 11 on each subscale). 30 years 75 years Both Presence of severe anterior segment ocular diseases including advanced keratoconus, corneal opacities, advanced glaucoma, and active uveitis. Presence of severe posterior segment diseases such as advanced age-related macular degeneration, proliferative diabetic retinopathy, retinal detachment, optic nerve atrophy, and other major macular disorders. History of brain surgery except for DBS. History of ocular trauma. Presence of manifest strabismus, paralytic deviations, or significant vertical deviations. History of amblyopia. Ocular conditions affecting binocular vision. Use of medications that interfere with binocular vision (other than antiparkinsonian drugs). Any change in antiparkinsonian drug dosage during the study. Use of medications that impair balance as confirmed by the medical team. Occurrence of any new debilitating comorbidity during the study that may affect participation. G20 Parkinson's disease Treatment - Other N/A Intervention Group: Structured Vision-Therapy ProgramParticipants in this group will receive a structured vision-therapy program consisting of evidence-based exercises derived from the Delphi phase of the study. The intervention includes standardized exercises targeting convergence, fusional vergence ranges, accommodative function, saccades, and smooth pursuits.The program will be delivered by trained optometrists. The duration (expected 8–12 weeks), frequency (2–3 sessions per week), and session length (30–45 minutes) will be finalized after the pilot study. Exercises progress from basic to advanced levels and include both in-clinic and home-based components.Monitoring will be conducted using structured checklists during each phase: (1) basic training, (2) advanced/extended exercises with compliance monitoring, and (3) review and consolidation of learned skills. Control Group: General Health Education + Placebo Vision TherapyParticipants in the control group will not receive active vision therapy. However, to maintain participant blinding, a placebo vision-therapy protocol will be administered. This placebo protocol consists of a set of exercises designed to resemble the structure, duration, and therapist–participant interaction of the active vision-therapy sessions, but without the therapeutic components expected to produce clinical improvement.In addition to the placebo intervention, the control group will receive a weekly standardized educational package containing information relevant to general health in individuals with Parkinson’s disease, including recommendations on nutrition, safe and light physical activity, environmental safety, and general symptom management.The number of sessions, their duration, and the content of the placebo exercises and educational materials will be matched to the intervention group and finalized based on the findings of the pilot study to ensure equal attention and contact time across both groups. Visual function, fear of falling, and vision-related quality of life in patients with idiopathic Parkinson’s disease. Timepoint: Baseline, post-intervention, and follow-up. Method of measurement: Visual function tests (acuity, stereopsis, contrast sensitivity, NPC, reading speed, vergence), fear of falling questionnaires, and vision-related quality of life questionnaires. Secondary outcomes include functional mobility and balance, contrast sensitivity and color vision, cognitive function, fusional vergence reserves and vergence facility, and the number of falls during the study period. These outcomes are measured using standardized tests and validated questionnaires. Timepoint: Baseline (before intervention), post-intervention, and follow-up. Method of measurement: Functional mobility and balance measured using standardized mobility and balance tests; contrast sensitivity and color vision measured with standard visual tests; cognitive function assessed using MoCA and PD-CRS; fusional vergence reserves and vergence facility assessed using optometric tests; number of falls recorded via patient diary or interview. Iran University of Medical Sciences Approved 2025-11-19 Ethics Committee of Iran University of Medical Sciences Shah-Nazari Tehran Tehran Iran (Islamic Republic of)