The Effect of Eggs and Egg Products on Macular Pigment
Condition: Age-related Macular Degeneration
MeSH terms: Macular Degeneration
Study type: Interventional

Summary: 
      Age-related macula degeneration (AMD, encompassing both dry and wet form), the late stage of
      Age-related maculopathy (ARM), is the leading cause of blindness in many developed countries
      in older persons (usually over 60 years of age). Visual compromise rises exponentially after
      the age of 70 with a 5-year incidence of around 1%. Studies have shown a possible protective
      effect of lutein on progression of AMD, where visual acuity improves after increased lutein
      intake. The incidence of bilateral AMD in persons with unilateral late ARM observed over a
      period of 10 years is over 50% with a 2.1-2.8% overall incidence in the study population.

      Blue light hazard (excitation peak 440 nm) was shown to have a major impact on photoreceptor
      and RPE function inducing photochemical damage and cellular apoptosis, leading to retinal
      degeneration in an animal study. The current belief is that lutein accumulated in the macular
      region helps in the prevention of blindness by absorbing blue light and protecting the retina
      from oxidative stress. With the lipid matrix of the egg yolk being a proven vehicle for the
      efficient absorption of dietary lutein, it might be possible to increase plasma levels of
      lutein to therapeutic levels and control or prevent AMD. This, the investigators hope, will
      be accomplished by means of filtering out harmful blue light and the scavenging of free
      radicals by lutein and zeaxanthin.
    

Detailed description: 
      This will be a randomized placebo-controlled trial. The total study time will be two years of
      which 3 months are actual trial and follow-up time. Every individual will have 3 measuring
      points at set intervals. At every measuring point (days 1, 45 and 90), these subjects will
      undergo 6 different non-invasive measuring techniques. These are the mean visual acuity test
      using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, contrast sensitivity
      using the Pelli-Robson chart, Scanning Laser Ophthalmoscope (SLO), Optical Coherence
      Tomography (OCT) and Heterochromatic Flicker Photometry (HFP) and the Reflectometer. A
      questionnaire will be taken at the beginning of the trail. The invasive part of the study
      involves blood sampling at all three times, measuring the serum concentration of lutein,
      zeaxanthin, omega-3 and lipoprotein using the HPLC analysis.
    

Intervention name(s): not enriched egg; lutein; zeaxanthin; egg product from enriched eggs
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): daily consumption of a regular egg, not enriched with either lutien nor zeaxanthin; daily lutein enriched egg; daily zeaxanthin enriched egg; daily egg product from lutein enriched eggs
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Prevention
Keywords: Macular pigment; AMD; ARM