NCT00065455

Investigating the Effect of Vitamin A Supplementation on Retinitis Pigmentosa

Completed Phase 1 Last updated 2 July 2017

What this trial tests

Phase 1 trial testing Vitamin A in Retinitis Pigmentosa in 11 participants. Completed in 6 May 2009.

Timeline

17 July 2003

6 May 2009

Quick facts

Lead sponsor	National Eye Institute (NEI)
Phase	Phase 1
Status	Completed
Study type	INTERVENTIONAL
Primary purpose	treatment
Enrollment	11
Start date	17 July 2003
Estimated completion	6 May 2009
Sites	1 location across United States

Drugs / interventions tested

• Vitamin A — full drug profile →

Conditions studied

• Retinitis Pigmentosa — all drugs for Retinitis Pigmentosa →

Sponsor

National Eye Institute (NEI)

Who can join

18 and older, any sex, with Retinitis Pigmentosa. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Retinitis pigmentosa (RP) is a collective term for a group of inherited retinal dystrophies that are a major cause of irreversible blindness. RP of some type occurs in approximately 1 out of 3500 persons in the United States(1). Gene mutations are responsible for the majority of RP. To date, mutations have been identified in 30 different genes linked to RP(2). The visual prognosis of RP is poor, since the gradual but relentless visual field loss leads eventually to some degree of blindness(3). Although no effective treatment for RP has been identified, participants supplemented with a daily oral dose of 15,000 IU vitamin A palmitate have shown, on average, a slower rate of deterioration of retinal function when the intervention is continued over several years(4). The purpose of this research is to determine whether administration of high oral doses of vitamin A can acutely improve cone photoreceptor function in RP participants as measured by electroretinography (ERG). In this interventional, non-randomized, prospective, pilot study, 5 participants will receive a daily oral dose of 50,000 IU of vitamin A palmitate for 4 weeks, followed by a maintenance dose of 15,000 IU daily for the subsequent 2 weeks. The primary efficacy outcome is a relative percentage change in ERG response amplitude subsequent to vitamin A supplementation. A secondary efficacy outcome is a relative percentage change in implicit time from pre- to post- vitamin A supplementation, with improvement specified as a shorter response implicit time. Other secondary outcomes will be improvements in visual field (Humphery, 10-2; sum of thresholds). Safety outcomes include visual fields, ETDRS visual acuity, intraocular pressure, serum vitamin A level and liver function tests.

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. Clinical and Rehabilitative Management of Retinitis Pigmentosa: Up-to-Date.
   Parmeggiani F, Sato G, De Nadai K, Romano MR, et al · · 2011 · cited 33× · PMID 22131870 · DOI 10.2174/138920211795860125
2. Inherited Retinal Dystrophies: Role of Oxidative Stress and Inflammation in Their Physiopathology and Therapeutic Implications.
   Pinilla I, Maneu V, Campello L, Fernández-Sánchez L, et al · · 2022 · cited 30× · PMID 35739983 · DOI 10.3390/antiox11061086