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Retinitis PigmentosaPhase 3NCT00000114

Randomized Trial of Vitamin A and Vitamin E Supplementation for Retinitis Pigmentosa

A Phase 3 study testing Vitamin E and Vitamin A in people with Retinitis Pigmentosa, run by National Eye Institute (NEI).

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

To determine whether supplements of vitamin A or vitamin E alone or in combination affect the course of retinitis pigmentosa. Read more about this study

Who is it for?
Ages 18 to 49 years
Conditions the study is for
Retinitis Pigmentosa
What is being tested?
Vitamin E and Vitamin A
How many people
Not given
Where
No sites listed yet
Study dates
May 1984to Jun 1987
Phase
Phase 3
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 49 years
  • All sexes
  • Adult

Men and nonpregnant women between ages 18 and 49 years with common forms of RP were included. All eligible patients had retinal arteriolar attenuation, elevated dark adaptation thresholds, and reduced ERGs. Patients had best corrected Snellen visual acuity of 20/100 or better, central visual field diameter on the Goldman perimeter with V4 e white test light of 8 degrees or greater, and ERG amplitude of 2.5 or greater in response to 0.5-Hz white light or of 0.12 ultraviolet light or greater in response to 30-Hz white flickering light in at least one eye. In addition, patients had normal fasting serum retinol and serum liver function profile and weight above the lower fifth percentile for age, sex, and height. All patients had a total estimated pre-trial intake of vitamins A and E from diet plus pills not greater than 11,500 IU/day and 40 IU/day, respectively.

About this study

To determine whether supplements of vitamin A or vitamin E alone or in combination affect the course of retinitis pigmentosa.

Read the detailed description

Retinitis pigmentosa (RP) is a group of inherited retinal degenerations with a worldwide prevalence of about 1 in 4,000. Patients typically report night blindness in adolescence and lose vision in the midperipheral followed by far-peripheral visual field in adulthood due to progressive loss of both rod and cone function. Most patients have reductions in central vision by age 50 to 80 years. Modern-day electroretinograms (ERGs) make it possible to record retinal responses from most patients with remaining vision and thereby monitor objectively the course of their disease.

While the natural course of retinal degeneration in the common forms of RP was being studied, it was noted that a subgroup of patients aged 18 through 49 who were treating themselves with both vitamin A and vitamin E and other nutritional supplements exhibited less decline in ERG amplitude over a 2-year period. These preliminary findings, as well as the known roles of vitamins A and E in maintaining normal photoreceptor function and structure, prompted this randomized, controlled trial to determine whether these vitamins alone or in combination would halt or slow the progression of the common forms of RP.

This study was a randomized, controlled double-masked trial with 2 x 2 factorial design and duration of 4 to 6 years. Patients were assigned to one of four treatment groups:

15,000 IU/day vitamin A

15,000 IU/day vitamin A + 400 IU/day vitamin E

trace amounts of both vitamins A and E

400 IU/day of vitamin E

The main outcome measure was the 30-Hz cone ERG amplitude. In addition, visual field and visual acuity were measured annually.

Being tested
Vitamin E, Vitamin A
Keywords
retinitis pigmentosa, vitamin supplements
Medical subject headings
Retinitis Pigmentosa

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Vitamin EDrug

  • Vitamin ADrug

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted24 Sep 1999 (estimated)
  2. Study startMay 1984
  3. Study completionJun 1987

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Factorial
Masking
Double blind
IDs, dates and publications
ClinicalTrials.gov ID
NCT00000114
Sponsor's protocol ID
NEI-10
Status last verified
Sep 2009
First submitted
23 Sep 1999
Last updated
17 Sep 2009
Results posted
No

Publications

  • Berson EL, Rosner B, Sandberg MA, Hayes KC, Nicholson BW, Weigel-DiFranco C, Willett W. A randomized trial of vitamin A and vitamin E supplementation for retinitis pigmentosa. Arch Ophthalmol. 1993 Jun;111(6):761-72. doi: 10.1001/archopht.1993.01090060049022.

    PubMed 8512476

  • Sandberg MA, Weigel-DiFranco C, Rosner B, Berson EL. The relationship between visual field size and electroretinogram amplitude in retinitis pigmentosa. Invest Ophthalmol Vis Sci. 1996 Jul;37(8):1693-8.

    PubMed 8675413

  • Comander J, Weigel DiFranco C, Sanderson K, Place E, Maher M, Zampaglione E, Zhao Y, Huckfeldt RM, Bujakowska KM, Pierce E. Natural history of retinitis pigmentosa based on genotype, vitamin A/E supplementation, and an electroretinogram biomarker. JCI Insight. 2023 Aug 8;8(15):e167546. doi: 10.1172/jci.insight.167546.

    PubMed 37261916

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Vitamin E and Vitamin A in people with Retinitis Pigmentosa, run by National Eye Institute (NEI).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 17 Sep 2009. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00000114, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Sep 2009.

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