Can placebo be successfully used to evaluate the efficacy of active treatments for dry eye disease?

Placebo does not appear to have a beneficial effect in the management of dry eye disease (DED) and can be used to investigate the efficacy of active treatments, according to a study.

In this meta-analysis and systematic review, data from 56 studies (12 205 patients) on randomized clinical trials investigating any active treatment against a placebo control group, were analyzed.

From baseline to last follow-up, placebo did not improve Ocular Surface Disease Index (OSDI), tear breakup time test (TBUT), Schirmer I test (SIT), and corneal staining. Active treatment led to a higher TBUT and SIT and a lower OSDI compared to placebo administration. No difference was found between placebo administration and active treatment in the 5 studies that reported data on corneal staining.

Reference
Prinz J, Maffulli N, Fuest M, et al. Placebo administration for dry eye disease: a level I evidence based systematic review and meta-analysis. Int J Clin Pharm. 2022;doi: 10.1007/s11096-022-01439-y. Epub ahead of print. PMID: 35939178.