How Strong Is the Evidence That Nutritional Supplements Slow the Progression of Retinitis Pigmentosa?

Massof, Robert W.; Fishman, Gerald A.

doi:10.1001/archophthalmol.2010.46

Cited by 38 publications

(11 citation statements)

References 9 publications

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“…Therefore, the effectiveness of antioxidant supplementation on antioxidant-oxidant status needs to be explored in detail. At present, the use of vitamin A and omega-3 fatty acids as appears to be an effective treatment for patient with RP, although the interpretation of clinical trials remains controversial [64]–[67]. Nonetheless several antioxidant treatments in experimental models of RP suggest a positive action of these treatments in slowing down or reducing the progression of the disease [6], [16], [68].…”

Section: Discussionmentioning

confidence: 99%

Altered Antioxidant-Oxidant Status in the Aqueous Humor and Peripheral Blood of Patients with Retinitis Pigmentosa

et al. 2013

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Retinitis Pigmentosa is a common form of hereditary retinal degeneration constituting the largest Mendelian genetic cause of blindness in the developed world. It has been widely suggested that oxidative stress possibly contributes to its pathogenesis. We measured the levels of total antioxidant capacity, free nitrotyrosine, thiobarbituric acid reactive substances (TBARS) formation, extracellular superoxide dismutase (SOD3) activity, protein, metabolites of the nitric oxide/cyclic GMP pathway, heme oxygenase-I and inducible nitric oxide synthase expression in aqueous humor or/and peripheral blood from fifty-six patients with retinitis pigmentosa and sixty subjects without systemic or ocular oxidative stress-related disease. Multivariate analysis of covariance revealed that retinitis pigmentosa alters ocular antioxidant defence machinery and the redox status in blood. Patients with retinitis pigmentosa present low total antioxidant capacity including reduced SOD3 activity and protein concentration in aqueous humor. Patients also show reduced SOD3 activity, increased TBARS formation and upregulation of the nitric oxide/cyclic GMP pathway in peripheral blood. Together these findings confirmed the hypothesis that patients with retinitis pigmentosa present reduced ocular antioxidant status. Moreover, these patients show changes in some oxidative-nitrosative markers in the peripheral blood. Further studies are needed to clarify the relationship between these peripheral markers and retinitis pigmentosa.

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Section: Discussionmentioning

confidence: 99%

Altered Antioxidant-Oxidant Status in the Aqueous Humor and Peripheral Blood of Patients with Retinitis Pigmentosa

et al. 2013

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“…Therefore, it is thought that this high-dose daily supplementation of vitamin A could be an effective therapy for retinitis pigmentosa in Usher syndrome. However, controversies exist regarding the validity of the conclusion drawn from the original data and the toxicity of the high dose of vitamin A (155, 156). In addition, the underlying mechanism of this vitamin A supplement therapy is uncertain, though retinal, a derivative of vitamin A, is an essential chromophore for phototransduction in photoreceptors.…”

Section: Therapeutic Studies For Ush2mentioning

confidence: 99%

Current understanding of usher syndrome type II

et al. 2012

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Usher syndrome is the most common deafness-blindness caused by genetic mutations. To date, three genes have been identified underlying the most prevalent form of Usher syndrome, the type II form (USH2). The proteins encoded by these genes are demonstrated to form a complex in vivo. This complex is localized mainly at the periciliary membrane complex in photoreceptors and the ankle-link of the stereocilia in hair cells. Many proteins have been found to interact with USH2 proteins in vitro, suggesting that they are potential additional components of this USH2 complex and that the genes encoding these proteins may be the candidate USH2 genes. However, further investigations are critical to establish their existence in the USH2 complex in vivo. Based on the predicted functional domains in USH2 proteins, their cellular localizations in photoreceptors and hair cells, the observed phenotypes in USH2 mutant mice, and the known knowledge about diseases similar to USH2, putative biological functions of the USH2 complex have been proposed. Finally, therapeutic approaches for this group of diseases are now being actively explored.

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“…For example, Dr Edward Norton, a member of the Data Safety and Monitoring Committee for Berson 1993, published his opinion that the data did not demonstrate a significant beneficial effect for vitamin A (Norton 1993). Similarly, Massof 2010 reviewed three RCTs, including Berson 1993 and Berson 2004a, and concluded that the results did not prove that these interventions slowed the rate of progression of RP.…”

Section: Discussionmentioning

confidence: 99%