Effectiveness of Dietary Supplementation for Retinitis Pigmentosa: A Report by the American Academy of Ophthalmology

PURPOSE

To review the evidence on the effectiveness of dietary supplementation for retinitis pigmentosa (RP).

METHODS

A literature search of the PubMed database was last conducted in January 2024 to identify published English-language original research on dietary supplementation for RP. Eligible compounds included products ingested orally containing nutrients intended to supplement the diet. Studies meeting eligibility criteria were assigned a level of evidence rating by the panel methodologist.

RESULTS

The search identified 283 citations, 15 of which met the assessment criteria. Two studies were rated level I, 11 studies were rated level II, and 2 studies were rated level III. All were single-center studies and were published between 1993 and 2022. The products evaluated included vitamin A, docosahexaenoic acid (DHA), lutein, vitamin E, goji berry (Lycium barbarum fruit) extract, and chlorogenic acid. Primary outcome measures were most commonly based on electroretinography (n = 7) or perimetry (n = 2) testing. Numerous studies highlighted data suggestive of possible efficacy for vitamin A, DHA, and lutein, yet these findings typically derived from secondary outcomes, evaluations of participant subsets, post hoc analyses, problematic interpretations of the data, or a combination thereof. Additionally, it was often unclear if the study findings represented clinically meaningful outcomes. No prominent safety concerns were reported in any study.

CONCLUSIONS

No high-quality evidence was found to support the effectiveness of any form of dietary supplementation for RP. The findings underscore the challenges of studying this rare and slowly progressive retinal disease. Future studies should leverage the enhanced recruitment abilities from collaborative research networks to refine eligibility criteria while using novel, clinically meaningful endpoints.