Advertisement

Topics

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

2014-08-27 04:00:17 | BioPortfolio

Summary

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

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.

Study Design

Allocation: Randomized, Intervention Model: Factorial Assignment, Masking: Double-Blind, Primary Purpose: Treatment

Conditions

Retinitis Pigmentosa

Intervention

Vitamin E, Vitamin A

Status

Completed

Source

National Eye Institute (NEI)

Results (where available)

View Results

Links

Published on BioPortfolio: 2014-08-27T04:00:17-0400

Clinical Trials [1060 Associated Clinical Trials listed on BioPortfolio]

Randomized Clinical Trial for Retinitis Pigmentosa

The purpose of this trial is to determine whether a nutritional supplement in addition to vitamin A will slow the course of retinitis pigmentosa.

Randomized Trial for Retinitis Pigmentosa

The purpose of this trial is to determine whether a nutritional supplement in addition to vitamin A will slow the course of retinitis pigmentosa.

Investigating the Effect of Vitamin A Supplementation on Retinitis Pigmentosa

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...

Studying a Potential Protective Effect of L-Dopa on Retinitis Pigmentosa

The purpose of this study is to evaluate the effect of L-Dopa on the progression of retinitis pigmentosa.

Safety Study in Retinal Transplantation for Retinitis Pigmentosa.

The long-term goal is to show that retinal transplantation can help to prevent blindness and to restore eyesight in patients with the inherited disease retinitis pigmentosa.

PubMed Articles [1219 Associated PubMed Articles listed on BioPortfolio]

Increased Prevalence of Flammer Syndrome in Patients with Retinitis Pigmentosa.

Background: "Retinitis pigmentosa" refers to a group of degenerative eye diseases with a genetic background. Flammer syndrome encompasses a set of symptoms and signs, mainly but not exclusively relate...

Vitamin D supplementation for everybody everytime?

Only few foods contain vitamin D in higher concentrations. Therefore, the main source of vitamin D is the dermal synthesis under the influence of UVB-light. By enzymatic hydroxylation vitamin D is con...

Vitamin D - old substance in new perspectives.

Receptors for vitamin D are present almost in all body tissues. Vitamin D does not only act as a regulator of calcium and phosphorus metabolism, but also a substance which modulates the immunity syste...

Relation between vitamin B12 and SYNTAX Score.

Vitamin B12 is required in the metabolism of homocysteine. Vitamin B 12 deficiency has been implicated in endothelial dysfunction and cardiovascular disease via hyperhomocysteinemia. However, the asso...

Plasma 3-Epi-25-Hydroxycholecalciferol Can Alter the Assessment of Vitamin D Status Using the Current Reference Ranges for Pregnant Women and Their Newborns.

Vitamin D is critical for healthy pregnancies and normal fetal development. It is important to accurately ascertain vitamin D status in mothers and their newborns to establish the optimal vitamin D co...

Medical and Biotech [MESH] Definitions

A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.

A nutritional condition produced by a deficiency of VITAMIN D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as RICKETS in children and OSTEOMALACIA in adults. (From Cecil Textbook of Medicine, 19th ed, p1406)

A family of phylloquinones that contains a ring of 2-methyl-1,4-naphthoquinone and an isoprenoid side chain. Members of this group of vitamin K 1 have only one double bond on the proximal isoprene unit. Rich sources of vitamin K 1 include green plants, algae, and photosynthetic bacteria. Vitamin K1 has antihemorrhagic and prothrombogenic activity.

Autosomal recessive hereditary disorders characterized by congenital SENSORINEURAL HEARING LOSS and RETINITIS PIGMENTOSA. Genetically and symptomatically heterogeneous, clinical classes include type I, type II, and type III. Their severity, age of onset of retinitis pigmentosa and the degree of vestibular dysfunction are variable.

A nutritional condition produced by a deficiency of VITAMIN E in the diet, characterized by posterior column and spinocerebellar tract abnormalities, areflexia, ophthalmoplegia, and disturbances of gait, proprioception, and vibration. In premature infants vitamin E deficiency is associated with hemolytic anemia, thrombocytosis, edema, intraventricular hemorrhage, and increasing risk of retrolental fibroplasia and bronchopulmonary dysplasia. An apparent inborn error of vitamin E metabolism, named familial isolated vitamin E deficiency, has recently been identified. (Cecil Textbook of Medicine, 19th ed, p1181)

More From BioPortfolio on "Randomized Trial of Vitamin A and Vitamin E Supplementation for Retinitis Pigmentosa"

Quick Search
Advertisement
 

Relevant Topic

Nutrition
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...


Searches Linking to this Trial