Lactoferrin for Dry Eye Disease

Finding: Tear lactoferrin is significantly lower in dry-eye patients than in healthy subjects (pooled mean difference 0.62 mg/mL, 95% CI 0.35-0.89), supporting lactoferrin as a diagnostic biomarker for dry eye but saying nothing about its efficacy as a treatment.

Finding: Oral lactoferrin 350 mg/day for 60 days post-cataract surgery significantly improved day-60 TBUT (13.9+/-0.99 s vs 7.86+/-0.86 s control) and Schirmer I (30.9+/-1.66 vs 15.86+/-5.83 mm) with fewer symptomatic patients (26.6% vs 42.8%), but the trial was single-centre, unblinded and used a no-treatment (not placebo) control.

Finding: A double-blind placebo-controlled trial of a COMBINATION supplement (fish oil + lactoferrin + zinc + vitamins C/E + lutein + GABA + a probiotic) improved subjective symptoms at weeks 4 and 8 (P<0.05) and raised Schirmer values, but the multi-ingredient design means the benefit cannot be attributed to lactoferrin alone.

Finding: This narrative review concludes lactoferrin has a plausible role in maintaining a healthy ocular surface but states 'further data from randomized controlled studies are desirable to confirm the efficacy of lactoferrin', i.e. efficacy for dry eye remains unproven.

Finding: This narrative review proposes lactoferrin and lactobionic acid as a candidate remedy for age-related dry eye but presents no controlled clinical outcome data, and its authors are affiliated with a company (Sooft Italia SpA) that markets lactoferrin-based eye products.

Finding: In a mouse model, oral lactoferrin ameliorated dry-eye signs, an effect linked to increased gut-microbiota short-chain fatty acid production; this is preclinical mechanistic evidence only and does not establish a human clinical effect.