The macula is the central and most vital part of the retina. Macular degeneration is a condition where this area degenerates, resulting in diminishing and even loss of sight. The condition tends to run in families. Macular degeneration can slowly or suddenly produce loss of vision. It is painless. It affects more than 10 million Americans. It is an incurable eye disease and that it is the leading cause of blindness for those aged 55 and older. As people age the chances for developing eye diseases increase dramatically.
There are two forms of macular degeneration, wet and dry. In dry macular degeneration (also called atrophic), a pigment is deposited in the macula; there is no indication of scaring, bleeding or other damage. In wet macular degeneration, an exudate is formed (leaked material) and forms a mound which is often surrounded by small hemorrhages. Eventually, the mound contracts and leaves a scar.
Research, appearing in the Archives of Ophthalmology ( June, 2011; 129(6): 758-66) looked at 2,167 subjects over the age of 55, 517 of whom had developed early age-related macular degeneration. Dietary intake was evaluated with a semiquantitative food frequency questionnaire, given at the beginning of the study. Genetic variants were determined using TaqMan assay. Incidentearly age-related macular degeneration was determined on fundus photographs at 3 follow-upvisits (median follow-up, 8.6 years). The synergy index wasused to evaluate biological interaction between risk factors;hazard ratios were calculated to estimate risk of early AMDin strata of nutrient intake and genotypes.
Significant synergy indices supported the possibilityof biological interaction between CFH Y402H and zinc, β-carotene,lutein/zeaxanthin, and eicosapentaenoic/docosahexaenoic acid(EPA/DHA) and between LOC387715 A69S and zinc and EPA/DHA (allP < .05). Homozygotes of CFH Y402H with dietaryintake of zinc in the highest tertile reduced their hazard ratioof early AMD from 2.25 to 1.27. For intakes of β-carotene,lutein/zeaxanthin, and EPA/DHA, these risk reductions were from2.54 to 1.47, 2.63 to 1.72, and 1.97 to 1.30, respectively.Carriers of LOC387715 A69S with the highest intake of zinc andEPA/DHA reduced their risk from 1.70 to 1.17 and 1.59 to 0.95,respectively (all P trends <.05).
Conclusions High dietary intake of nutrients with antioxidantproperties reduces the risk of early AMD in those at high genetic risk. Therefore, clinicians should provide dietary advice toyoung susceptible individuals to postpone or prevent the vision-disablingconsequences of AMD.
