Randomised controlled trial of CAM training vs occlusion for amblyopia therapy
Reviewed by Fiona Rowe

The main aim of this study was to compare the effect of Cambridge vision stimulator (CAM) therapy with passive occlusion in the management of unilateral amblyopia. This was an randomised control trial (RCT) with two groups; group 1 with CAM therapy and group 2 with occlusion therapy. Children were aged 4–10 years with anisometropic amblyopia, strabismic amblyopia, or both, with corrected distance visual acuity of <0.1logMAR. Cambridge vision stimulator therapy was undertaken with the fellow eye occluded twice per week at 30 minutes per session for three months (total 26 sessions). The child painted on a translucent plate over the rotary disc. Occlusion for severe amblyopia was six hours per day and for moderate amblyopia was two hours per day. Assessments were done at baseline and at one-, two- and three-months follow-up. The study recruited 110 patients with mean age of 7.0 ±2.0 years: 55 CAM training and 55 occlusion. Visual acuity improved in the CAM group from a mean of 0.45 ±0.24logMAR to 0.05 ±0.08 at three months; and for the occlusion group from 0.40 ±0.23logMAR to 0.05 ±0.06. There was no significant difference between groups for level of improvement. Limitations of this study were the lack of sham treatment. Treatment outcomes were comparable. The authors conclude that whilst occlusion is less expensive and time-consuming than CAM therapy, if there are considerable compliance issues, CAM may be a potential alternative treatment option but does require in-office supervised treatment visits which have cost and time implications.

Comparison of Cambridge vision stimulator (CAM) therapy with passive occlusion therapy in the management of unilateral amblyopia; a randomised clinical trial.
Khorrami-Nejad M, Akbari MR, Abdulhussein R, Azizi E.
STRABISMUS
2024;32(3):123–38.