N-acetylcarnosine (NAC) drops for age-related cataract.
Level 1 - systematic review of randomized trials
Cochrane systematic review of randomized and quasi-randomized controlled trials
PubMed 28245346 · doi:10.1002/14651858.CD009493.pub2
What was done
A Cochrane systematic review searched major biomedical databases (CENTRAL, MEDLINE, Embase, AMED, CINAHL, trial registries, and conference proceedings up to June 2016) without language restrictions. The review sought randomized or quasi-randomized controlled trials comparing N-acetylcarnosine (NAC) eye drops to control in people with age-related cataract.
What was found
Two potentially eligible studies enrolling 114 participants (aged 55 to 80 years) were identified (one with 6-month and 2-year arms; one lasting 4 months). Because essential methodological details could not be verified from the authors, both studies were designated as 'awaiting classification.' No pooled quantitative data were reported, and no convincing evidence was found that NAC prevents or reverses cataract progression.
Why it matters
Despite biochemical rationale for antioxidant eye drops as a non-surgical cataract therapy, no reliable clinical trial evidence currently supports the efficacy of N-acetylcarnosine.
Limits
Neither identified study had sufficient reporting or verified design details to permit formal inclusion or meta-analysis. Adequately powered, double-masked, placebo-controlled randomized trials evaluating visual acuity, contrast sensitivity, glare, quality of life, and safety are absent.
Cited by
- context N-acetylcarnosine eye drops penetrate the eye and act as a decoy to prevent lens glycation in cataracts.
- contradicts N-acetylcarnosine drops work to treat cataracts in dogs.