Omega-3-fatty Acids on Age-related Macular
Condition: Aged Macular Degeneration
MeSH terms: Macular Degeneration
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): Omega 3; Olive Oil
Intervention type(s): Dietary Supplement; Other
Intervention description(s): Omega-3-fatty acids 4 gm oral daily (Total:840mg EPA/2520mg DHA) (1:3 ratio of EPA to DHA) ( 6 capsules fatty acids); ii. Placebo oral daily (6 softgel capsules, each contains 1100 mg olive oil)
Allocation: Randomized
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Prevention