NCT05045703

The Dark-Adapted Retinal Function Response in Choroideremia (DARC) Study

Characterization of Night Vision Impairment in Choroideremia and Short-Term Vitamin A Supplementation: The Dark-Adapted Retinal Function Response in Choroideremia (DARC) Study

• Status: Withdrawn
• Phase: N/A
• Study type: Interventional
• Enrollment: 0 (actual)
• Sponsor: Duke University · Academic / Other
• Sex: Male
• Age: 15 Years
• Healthy volunteers: Accepted

Summary

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.

Conditions

• Choroideremia

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	Vitamin A palmitate	Vitamin A palmitate, 15,000 IU daily for 4 months

Timeline

• Start date: 2023-05-01
• Primary completion: 2024-03-01
• Completion: 2024-05-01
• First posted: 2021-09-16
• Last updated: 2023-06-29

Locations

1 site across 1 country: United States