Evidence map›Paper›PMID 39374001›Full record

Trial reportTranslational vision science & technology2024

Retinal Function in Young Adults Following Topical Application of Levodopa to the Eye.

Faran Sabeti, Kate Thomson, Ted Maddess, Cindy Karouta, Myra Leung, Nicola Anstice, Tina Jong, Regan Ashby

Registry-linked trialAbstract readRandomized Controlled TrialClinical Trial, Phase I
In one paragraph

Trial report in Translational vision science & technology, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT07748715 (Blue Color Processing in the Eye as a Biomarker of Brain Dopamine), which is not on this map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT07748715 not yet recruitingnot on this mapstarted 2026, after this paper: background citation

Blue Color Processing in the Eye as a Biomarker of Brain Dopamine

TypeobservationalSponsorUniversity of South FloridaRan2026 to 2027Enrolled50ConditionsParkinson Disease, Healthy Adult ParticipantsArmsLevadopa/Carbidopa eyedrops, Sham, Levodopa/Carbidopa (Sinemet)
3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Faran SabetiDiscipline of Optometry, Faculty of Health, University of Canberra, Canberra, Australia.
Kate ThomsonCentre for Research into Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia.
Ted MaddessJohn Curtin School of Medical Research (JCSMR), The Australian National University, Canberra, Australia.
Cindy KaroutaCentre for Research into Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia.
Myra LeungDiscipline of Optometry, Faculty of Health, University of Canberra, Canberra, Australia.
Nicola AnsticeDiscipline of Optometry, College of Nursing and Health Sciences, Flinders University, Adelaide, Australia.
Tina JongDiscipline of Optometry, Faculty of Health, University of Canberra, Canberra, Australia.
Regan AshbyCentre for Research into Therapeutic Solutions, Faculty of Science and Technology, University of Canberra, Canberra, Australia.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: Levodopa has been investigated as a therapeutic solution for ocular disorders involving dysregulation of the dopaminergic system, especially in the context of myopia. However, given the critical role dopamine plays in normal vision, this phase I trial examined whether levodopa/carbidopa eye drops induce any regional changes in retinal structure and function. Methods: Twenty-nine healthy male subjects 18 to 30 years of age were randomly assigned to receive either a low (1.4/0.34 µmoles/day, n = 14) or high (2.7/0.68 µmoles/day, n = 15) dose of levodopa/carbidopa eye drops in 1 eye for 28 consecutive days. A placebo solution was applied to all fellow eyes. Measures included visual acuity, regional frequency doubling perimetry, regional multifocal electroretinogram (mfERG) and optical coherence tomography (retinal thickness). Outcome measures were undertaken at baseline, end-of-treatment (4 weeks), and at a follow-up (4 months post-treatment). Results: For low dose treated eyes, regional analysis showed a small, statistically significant change in mfERG recordings (increase in ring 5 amplitude in low dose treated eyes, P < 0.05) and the retinal thickness map (localized retinal thinning in low dose treated eyes, P < 0.05). These changes were not clinically significant. No significant changes were observed in high dose treated eyes. Pharmacokinetic analysis (rabbits) demonstrated that levodopa was not detectable within blood and peaked within the eye at 15 to 30 minutes (and eliminated within 4 hours). Conclusions: No clinically significant effects of levodopa/carbidopa eye drops were found with regard to normal retinal structure and function following short-term use. Translational Relevance: This study further demonstrates the safety of topical levodopa, which may support its use in the treatment of ocular disorders in which the dopamine system is dysregulated.

Indexed as

CarbidopaElectroretinographyLevodopaOphthalmic SolutionsRetinaTomography, Optical CoherenceVisual AcuityAdolescentAdultDopamine AgentsDouble-Blind MethodDrug CombinationsHumansMaleVisual Field TestsYoung AdultCarbidopacarbidopa, levodopa drug combinationDopamine AgentsDrug CombinationsLevodopaOphthalmic Solutions

Identifiers

PMID39374001
PMCPMC11463705

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Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.