Trial reportInvestigative ophthalmology & visual science2015
Docosahexaenoic Acid Slows Visual Field Progression in X-Linked Retinitis Pigmentosa: Ancillary Outcomes of the DHAX Trial.
Trial report in Investigative ophthalmology & visual science, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT00100230 (Investigation of Effectiveness and Safety of High Dose Docosahexaenoic Acid), which is not on this map. Cited by 37 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Investigation of Effectiveness and Safety of High Dose Docosahexaenoic Acid (DHA) in X-Linked Retinitis Pigmentosa
Who cites it
37 citing papers in PubMed, 2 syntheses or guidelines pooled it, 68 citations in OpenAlex.
- Vitamin A and fish oils for preventing the progression of retinitis pigmentosa.The Cochrane database of systematic reviews · 2020Pooled it
- Effectiveness and safety of nutritional supplements in the treatment of hereditary retinal dystrophies: a systematic review.Eye (London, England) · 2017Pooled it
- Post hoc analysis of a randomized placebo-controlled trial suggests potential visual benefits of branched-chain amino acids in retinitis pigmentosa.Scientific reports · 2025Trial
- Efficacy and Safety of Branched Chain Amino Acids on Retinitis Pigmentosa: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial.Translational vision science & technology · 2024Trial
- Natural history of retinitis pigmentosa based on genotype, vitamin A/E supplementation, and an electroretinogram biomarker.JCI insight · 2023Trial
- Effect of Oral Valproic Acid vs Placebo for Vision Loss in Patients With Autosomal Dominant Retinitis Pigmentosa: A Randomized Phase 2 Multicenter Placebo-Controlled Clinical Trial.JAMA ophthalmology · 2018Trial
- Long-term Follow-up of Patients With Retinitis Pigmentosa Receiving Intraocular Ciliary Neurotrophic Factor Implants.American journal of ophthalmology · 2016Trial
- Nutritional supplements: current evidence for retinitis pigmentosa and Stargardt disease.Current opinion in ophthalmology · 2026Review
- Age-Stratified Genetic Spectrum of Retinitis Pigmentosa in Korean Patients: Predominance ofAnnals of laboratory medicine · 2026Article
- Scientific Opinion on the tolerable upper intake level for supplemental docosahexaenoic acid.EFSA journal. European Food Safety Authority · 2026Article
- Progression of Dark-Adapted Visual Fields Over 3 Years in the Rate of Progression in USH2A-Related Retinal Degeneration (RUSH2A) Study.Investigative ophthalmology & visual science · 2025Article
- Pre-Clinical and Clinical Advances in Gene Therapy of X-Linked Retinitis Pigmentosa: Hope on the Horizon.Journal of clinical medicine · 2025Review
- Type 2 Usher Syndrome - A Cause for Sensorineural Hearing Loss.Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India · 2024Article
- Retinitis Pigmentosa and Therapeutic Approaches: A Systematic Review.Journal of clinical medicine · 2024Review
- External Disruption of Ocular DevelopmentThe Yale journal of biology and medicine · 2024Review
- Retinitis Pigmentosa: From Pathomolecular Mechanisms to Therapeutic Strategies.Medicina (Kaunas, Lithuania) · 2024Review
- Oxidative Stress and Antioxidant-Based Interventional Medicine in Ophthalmology.Pharmaceuticals (Basel, Switzerland) · 2023Review
- How to Set Up Genetic Counselling for Inherited Macular Dystrophies: Focus on Genetic Characterization.International journal of molecular sciences · 2023Review
- Retinitis Pigmentosa: Current Clinical Management and Emerging Therapies.International journal of molecular sciences · 2023Review
- Relationship between visual acuity and visual field and its reproducibility in patients with retinitis pigmentosa.Eye (London, England) · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 5 institutions in 1 country.
Funding
Abstract
purposeDocosahexaenoic acid (DHA) was supplemented in a single-site, placebo-controlled, randomized clinical trial designed to slow vision loss associated with X-linked retinitis pigmentosa (XLRP); the DHAX Trial. We previously reported no significant differences between supplemented and placebo groups in intent-to-treat analysis of primary ERG outcomes. Assessed herein are hypothesis-generating measures of ancillary visual function outcomes in participants fully adhering to trial protocol.
methodsMale participants with XLRP (range, 7-31 years) received 30 mg DHA/kg/d (n = 29) or placebo (n = 22) for 4 years. Visual outcomes were measured annually and red blood cell (RBC) DHA determined every 6 months.
resultsOral DHA supplementation increased mean RBC-DHA levels by 4-fold (P < 0.0001) over placebo. No group differences in progression were found for visual acuity (P = 0.11), shape discrimination (P = 0.18), or fundus appearance (P = 0.70). Optical coherence tomography (OCT) became available during year 2 of the trial; no group differences were seen in ellipsoid zone constriction (P = 0.87) over 2 years. Yearly rates of progression were reduced for dark-adapted thresholds (P = 0.06) and visual field sensitivity for foveal, macular, peripheral, total, and ellipsoid zone regions by DHA supplementation (P = 0.039, P = 0.031, P < 0.0001, P < 0.0001, and P = 0.033). Rates of visual field sensitivity decline were dependent on RBC-DHA (P = 0.046 to <0.0001).
conclusionsSupplementation of DHA significantly elevated blood DHA levels and reduced the rate of progression in final dark-adapted thresholds and visual field sensitivity. From the relationship between RBC-DHA and the rate of field sensitivity loss, we can extrapolate that an RBC-DHA level of 17% could minimize the decline in field sensitivity. (ClinicalTrials.gov number, NCT00100230.)
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.