Optometry Notes: Nutrition in AMD

Pharmacologic treatments for wet AMD

Natural history of AMD progression

10% rate of conversion from dry to wet AMD
nutritional supplementation decreases risk
oxidation hypothesis: breakdown of antioxidant systems and generation of free radicals damages lipid membranes; antioxidant deficiency may predispose patient to disease

AMD and cardiovascular disease

shared risk factors: elevated lipids, cholesterol, CRP, arteriosclerosis, cigarette smoking, inflammatin, HTN

AREDS

category 1 or 2 (little-to-no AMD or few small drusen): risk of developing wet AMD at 5 years = 1.5%
category 3 (large intermediate-size drusen or nonvoeal geographic atrophy): risk of developing wet AMD at 5 years = 20%
category 4 (at least 1 eye with wet AMD or foveal geographic atrophy)
if wet AMD present in one eye, risk to the fellow eye is 45%
risk for vision loss at 5 years: antioxidant + zinc = 20% reduction in risk
risk for progression to wet AMD at 5 years: antioxidant + zinc or zinc alone = 25% reduction in risk
recommendations: patients with intermediate to advanced AMD (category 3 or 4) should take daily supplemental theraphy
people who smoke should avoid beta carotene due to increased risk of lung cancer

AREDS II

study of lutein, zeaxanthin, omega-3 fatty acids
lutein and zeaxanthin are natural carotenoids found in macula; antioxidants; filters of UV light; play role in structural signal transduction; macular pigment decreases with age; decrease predisposes patient to increased rsik for AMD
zeaxanthin can increase macular pigment
6m lutein associated with reduced risk for develping AMD by up to 43%

Dietary fat

higher body mass index associated with greater AMD risk
high intake of fat in prcessed baked gods increases odds for developing wet AMD by 2.4
other sources of fat (nuts) protective

Omega-3 fatty acids

lutein, zeaxanthin, and omega-3 fatty acids not produced by body
high intake of omega-3 fatty acids protects against wet AMD (dose-dependent)
omega-3 fatty acids in broiled or baked fish: dose-dependent decrease in risk for AMD progression

Side-effects/interactions

high levels of beta-carotene linked to increased incidence of lung cancer among heavy smokers
high volumes of zinc linked with genitourinary and GI disorders

Optometry Notes