Experts who recently conducted a literature review assessing the efficacy of binocular therapy to treat amblyopia determined that it cannot recommend the option as a replacement for standard approaches. Despite promising results from small case studies, the more rigorously designed studies have not yielded consistent evidence of efficacy for binocular treatments of amblyopia.

The researchers, from the American Academy of Ophthalmology’s Ophthalmic Technology Assessment Committee Pediatric Ophthalmology/Strabismus Panel, assigned a level of evidence rating to 20 studies—a level I rating was assigned to well-designed and well-conducted randomized clinical trials; level II denoted well-designed case-control and cohort studies and lower-quality randomized studies; and a level III indicated case series, case reports and lower-quality cohort and case-control studies. Six studies were rated level I, one study was rated level II and 13 studies were rated level III.

Two of the level I and II studies described a significant improvement in visual acuity in the binocular group vs. standard patching standard treatment (147 patients in all). However, the other five studies failed to show a visual improvement from binocular therapy compared with standard treatments and were larger and more rigorously designed (a total of 813 patients). The level I and II studies also failed to show a significant improvement over baseline in sensory status, such depth of suppression and stereopsis of those treated with binocular therapy.

Still, several smaller level III case series (13 studies, 163 patients) revealed more promising results than the binocular treatments studied in level I and II studies. The researchers from the Academy noted that these studies were using treatments that were considered more engaging and associated with better compliance. The review concluded that further research and more rigorous study of newer, more engaging therapies would help better determine whether they have a role as an adjunct to or replacement of the current standard treatment options.