The Dark-Adapted Retinal Function Response in Choroideremia (DARC) Study
Public ClinicalTrials.gov record NCT05045703. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
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Official title
Characterization of Night Vision Impairment in Choroideremia and Short-Term Vitamin A Supplementation: The Dark-Adapted Retinal Function Response in Choroideremia (DARC) Study
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Choroideremia (CHM) is an inherited retinal disorder that causes progressive vision loss, ultimately leading to complete blindness. The first symptom is generally night blindness, although, to date, little is known about the extent, type, pattern, and progression of dark-adapted visual function measures in CHM patients. We hypothesize that one of the key events causing night blindness in CHM is deficiency in the chromophore of the rod visual pigment, rhodopsin. We propose that this deficiency is at least in part due to inadequate delivery of vitamin A (all-trans-retinol) to the photoreceptors (PRs) from the ailing retinal pigment epithelium (RPE), characteristic of CHM. We hypothesize that increased availability of vitamin A would potentiate its entry into the RPE-mediated visual cycle, ultimately enabling delivery to the PRs. This would in turn allow rods to perform better by partially overcoming the RPE damage and the impaired chromophore recycling that we postulate exists in CHM. The goals of this proposal are: (1) to test the hypothesis that oral vitamin A supplementation can improve night time and peripheral vision in CHM patients, and (2) to provide detailed characterization of dark-adapted visual function outcome measures to guide interventional CHM trials.
Study identification
- NCT ID
- NCT05045703
- Recruitment status
- Withdrawn
- Study type
- Interventional
- Phase
- Not applicable
- Enrollment
- Not listed
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 15 Years and older
- Sex
- Male
- Healthy volunteers
- Accepts healthy volunteers
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Apr 30, 2023
- Primary completion
- Feb 29, 2024
- Completion
- Apr 30, 2024
- Last update posted
- Jun 28, 2023
2023 – 2024
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Duke Eye Center | Durham | North Carolina | 27710 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT05045703, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Jun 28, 2023 · Synced Sep 6, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT05045703 live on ClinicalTrials.gov.