The safety and tolerability of levodopa eye drops for the treatment of ocular disorders: A randomized first-in-human study

Kate Thomson, Cindy Karouta, Faran Sabeti, Nicola Anstice, Myra Leung, Tina Jong, Ted Maddess, Ian G. Morgan, Jeremy Game, Regan Ashby

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


Myopia is the leading cause of low vision worldwide and can lead to significant pathological complications. Therefore, to improve patient outcomes, the field continues to develop novel interventions for this visual disorder. Accordingly, this first-in-human study reports on the safety profile of a novel dopamine-based ophthalmic treatment for myopia, levodopa/carbidopa eye drops. This phase I, first-in-human, monocenter, placebo-controlled, double-blind, paired-eye, multidose, randomized clinical trial was undertaken in healthy adult males aged 18–30 years (mean age 24.9 ± 2.7) at the University of Canberra Eye Clinic, Australia. Participants were randomly assigned to receive either a low (1.4 levodopa:0.34 carbidopa [μmoles/day], n = 14) or standard dose (2.7 levodopa:0.68 carbidopa [μmoles/day], n = 15) of levodopa/carbidopa eye drops in one eye and placebo in the fellow eye once daily for 4 weeks (28 days). Over this 4-week trial, and after a 4-month follow-up visit, levodopa/carbidopa treatment had no significant effect on ocular tolerability and anterior surface integrity, visual function, ocular health, refraction/ocular biometry, and did not induce any non-ocular adverse events. These results indicate that topical levodopa/carbidopa is safe and tolerable to the eye, paving the way for future studies on the efficacy of this novel ophthalmic formulation in the treatment of human myopia. The findings of this study have implications not only for the treatment of myopia, but in a number of other visual disorders (i.e., amblyopia, diabetic retinopathy, and age-related macular degeneration) in which levodopa has been identified as a potential clinical intervention.

Original languageEnglish
Pages (from-to)2673-2684
Number of pages12
JournalClinical and Translational Science
Issue number11
Publication statusPublished - Nov 2022


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