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IRCT20120723010364N4 IRCT 2026-01-13 Tehran University of Medical Sciences Comparison of CAM and Sham CAM in Pediatric Unilateral Amblyopia CAM-A Trial Comparison of Cambridge Vision Stimulator (CAM) Therapy with Sham CAM Therapy in Patients with Unilateral Functional Amblyopia: A Randomized Clinical Trial. 2025-10-23 anticipated 132 Recruiting https://irct.ir/trial/88331 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Other design features: A distinctive feature of this study is the inclusion of a Sham CAM group as a non-pharmacological placebo control, which allows differentiation between the true effect of CAM visual stimulation and the effect of short-term occlusion. In addition, the use of stratified randomization based on amblyopia type and severity ensures balanced groups, and multiple follow-up assessments (at 1, 2, and 4 months) enable evaluation of treatment effects over time, Randomization description: A stratified block randomization method will be used. Participants will be stratified based on type of amblyopia (anisometropia, strabismus, combined) and baseline CDVA severity (mild, moderate, severe). Within each stratum, participants will be randomly assigned to CAM therapy, Sham CAM therapy, or occlusion therapy. The unit of randomization is the individual participant. The random sequence will be generated using statistical software, and group allocation will be implemented through sealed, opaque, sequentially numbered envelopes. Envelopes will be opened only after enrollment to ensure allocation concealment, Blinding description: In this study, participants and their parents/caregivers will be blinded to the type of assigned intervention. In addition, outcome assessors measuring corrected distance visual acuity will be blinded to group allocation. Although the therapist administering the intervention will be aware of the treatment type, they will not be involved in outcome assessment or data analysis. Therefore, the study is conducted as a double-blind trial. N/A Unilateral Functional Amblyopia. Intervention 1: Control group: Sham therapy using the Cambridge Vision Stimulator (CAM) device.Participants in this group view the CAM device displaying uniform gray plates with no spatial patterns. Each treatment session lasts 30 minutes, conducted three times per week for a total duration of 4 weeks (12 sessions in total). Sessions are supervised directly by a trained optometrist in the clinic. During the sessions, the non-amblyopic eye is occluded using a standard eye patch. The device used is the standard model Cambridge Vision Stimulator (manufacturer: Clement Clarke International). Intervention 2: Intervention group: Intervention Group 1:Active therapy using the Cambridge Vision Stimulator (CAM) device.Participants in this group view the CAM device displaying rotating sinusoidal grating patterns with various spatial frequencies (2, 6, 15, 20, and 30 cycles per degree). Each treatment session lasts 30 minutes, conducted three times per week for a total duration of 4 weeks (12 sessions in total). Sessions are supervised directly by a trained optometrist in the clinic. During the sessions, the non-amblyopic eye is occluded using a standard eye patch. The device used is the standard model Cambridge Vision Stimulator (manufacturer: Clement Clarke International). Intervention 3: Intervention group: Intervention Group 2:Standard occlusion therapy.Participants in this group receive patching of the sound eye according to clinical guidelines based on age and amblyopia severity. Patching duration is determined as follows: Severe amblyopia (CDVA worse than 20/100 or 0.7 logMAR): 6 hours per day Moderate amblyopia (CDVA between 20/80–20/40 or 0.6–0.3 logMAR): 2 hours per day Mild amblyopia (CDVA between 20/40–20/30 or 0.3–0.2 logMAR): 2 hours per day Treatment lasts 4 weeks and is administered at home using a standard optical occlusive eye patch (e.g., Orthoptic Eye Patch) under parental supervision. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is At present, no final decision has been made regarding sharing of de-identified individual participant data, data dictionaries, study protocol, or statistical analysis plan, and this decision will be made at the time of publication of the study results
public Dr. Hesam Hashemian
School of Rehabilitation, Tehran University of Medical Sciences, Enghelab Street, Pich-e-Shemiran, Tehran, Iran
Tehran Iran (Islamic Republic of) 1148965111 +98 21 7753 3939 h-hashemian@tums.ac.ir Tehran University of Medical Sciences scientific Dr. Hesam Hashemian
School of Rehabilitation, Tehran University of Medical Sciences, Enghelab Street, Pich-e-Shemiran, Tehran, Iran
Tehran Iran (Islamic Republic of) 1148965111 +98 21 7753 3939 h-hashemian@tums.ac.ir Tehran University of Medical Sciences Iran (Islamic Republic of) Age between 4 and 8 years Diagnosis of unilateral functional amblyopia Corrected distance visual acuity (CDVA) worse than 0.1 logMAR in the amblyopic eye Presence of at least one amblyogenic factor including anisometropia, strabismus, or both No previous amblyopia treatment except refractive error correction Full-time use of appropriate optical correction for at least 4 months prior to enrollment Cooperation of the child and parents for examinations and follow-up visits Written informed consent obtained from parents or legal guardians 4 years 8 years Both Presence of organic amblyopia. History of previous amblyopia treatment other than refractive correction. History of strabismus surgery. Presence of systemic diseases affecting ocular anatomy or visual function. Premature birth. Presence of ocular pathology other than amblyopia. H53.0 Amblyopia ex anopsia Treatment - Devices Treatment - Devices Treatment - Devices Control group: Sham therapy using the Cambridge Vision Stimulator (CAM) device.Participants in this group view the CAM device displaying uniform gray plates with no spatial patterns. Each treatment session lasts 30 minutes, conducted three times per week for a total duration of 4 weeks (12 sessions in total). Sessions are supervised directly by a trained optometrist in the clinic. During the sessions, the non-amblyopic eye is occluded using a standard eye patch. The device used is the standard model Cambridge Vision Stimulator (manufacturer: Clement Clarke International). Intervention group: Intervention Group 1:Active therapy using the Cambridge Vision Stimulator (CAM) device.Participants in this group view the CAM device displaying rotating sinusoidal grating patterns with various spatial frequencies (2, 6, 15, 20, and 30 cycles per degree). Each treatment session lasts 30 minutes, conducted three times per week for a total duration of 4 weeks (12 sessions in total). Sessions are supervised directly by a trained optometrist in the clinic. During the sessions, the non-amblyopic eye is occluded using a standard eye patch. The device used is the standard model Cambridge Vision Stimulator (manufacturer: Clement Clarke International). Intervention group: Intervention Group 2:Standard occlusion therapy.Participants in this group receive patching of the sound eye according to clinical guidelines based on age and amblyopia severity. Patching duration is determined as follows: Severe amblyopia (CDVA worse than 20/100 or 0.7 logMAR): 6 hours per day Moderate amblyopia (CDVA between 20/80–20/40 or 0.6–0.3 logMAR): 2 hours per day Mild amblyopia (CDVA between 20/40–20/30 or 0.3–0.2 logMAR): 2 hours per day Treatment lasts 4 weeks and is administered at home using a standard optical occlusive eye patch (e.g., Orthoptic Eye Patch) under parental supervision. Change in corrected distance visual acuity (CDVA) of the amblyopic eye, measured using the ETDRS logMAR chart at baseline and at 1, 2, and 4 months after the intervention. Timepoint: The primary outcome will be measured at baseline (before the intervention) and at 1, 2, and 4 months after initiation of the intervention. Method of measurement: Corrected distance visual acuity is measured using the Early Treatment Diabetic Retinopathy Study distance visual acuity chart, and results are recorded on the logarithm of the minimum angle of resolution scale. Tehran University of Medical Sciences Approved 2025-10-22 Ethics Committee of the School of Nursing and Midwifery and the School of Rehabilitation, Tehran Uni Keshavarz Boulevard, Quds Intersection, Central Administration of Tehran University of Medical Sciences Tehran Tehran Iran (Islamic Republic of)