Aged Macular Degeneration Clinical Trial
Official title:
Short Term Ocular Safety Assessment of High Dose Omega-3 Supplementation for Age-Related Macular Degeneration.
Aim: To demonstrate the short-term multi focal electroretinogram (mfERG) effect of oral
omega-3-fatty acids in the triglyceride form on dry age-related macular degeneration (AMD).
Null hypothesis: Omega-3-fatty acids do not affect the mfERGs of patients with dry AMD.
There is a growing amount of basic science data supporting the use of omega 3 fatty acids in
AMD. Koto et al. report that eicosapentaenoic acid, a major omega-3 polyunsaturated fatty
acid, prevents CNVM in mice. Conner et al. report in Nature Medicine that increased dietary
intake of omega-3-polyunsaturated fatty acids reduces pathological retinal angiogenesis in
mice. Miyauchi et al. looked at ERG outcomes in rabbits. They report that an intraperitoneal
injection of docosahexaenoic acid given 5 hours before IOP induced ischemia resulted in
better ERG amplitudes than controls. Docosahexaenoic acid appears to protect against
transient retinal ischemia.
Clinical data on this topic is scarce. A systemic review was published in Retina in 2007
(Hodge, et al.) outlining the limited data. A recent meta-analysis by Chong et al. of nine
studies found a high dietary intake of omega-3 fatty acids decreased risk of late AMD by
38%, though the current literature is insufficient to support routine consumption to prevent
AMD. Scorolli et al. conducted a randomized control trial on 35 bilateral wet AMD patients
receiving photodynamic therapy with our without vitamin E, linolenic acid, alpha-linolenic
acid, and docosahexaenoic acid (DHA). The latter two are omega-3-fatty acids. Patients in
the polyunsaturated fatty acid (PUFA) group had significantly shorter recovery time after
macular flash. Visually acuity was not statistically different between the two groups. Feher
et al. conducted a randomized control trial using acetyl-L-carnitine, omega-3 fatty acids,
and coenzyme Q10 (Phototrop). They report findings that strongly suggest that an appropriate
combination of compounds that affect mitochondrial lipid metabolism may improve and
subsequently stabilize visual functions, and it may also improve fundus alterations in
patients affected by early AMD. The Blue Mountain Eye Study, a cohort study, reports a
regular diet high in omega-3 polyunsaturated fat, especially from fish, seems to protect
against early and late ARM. Seddon et al. performed a clinic-based case-control study across
five centers, concluding diets high in omega-3 fatty acids and fish are inversely associated
with risk for AMD when intake of linoleic acid was low. Augood et al. published a
cross-sectional study of 105 cases, reporting eating oily fish at least once per week
compared with less than once per week decreased the odds ratio for neovascular AMD by half.
Few authors have evaluated the role of ERG in treating AMD. A recent review by Gerth
concludes ERG is an important tool in assessing retinal function in AMD and as an outcome
measure. Multifocal ERG, possibly combined with other tests, has the greatest value.
Hishihara et al. have evaluated the amplitude and implicit time changes in neovascular AMD
using focal macular ERGs.
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Allocation: Randomized, Endpoint Classification: Efficacy Study, Masking: Double Blind (Subject, Caregiver, Investigator), Primary Purpose: Prevention