Age-related macular degeneration
Age-related macular degeneration is a leading cause of irreversible blindness in older adults in resource-rich countries, presenting as painless central vision loss from drusen and retinal pigment epithelium change (dry AMD) or choroidal neovascularization (wet AMD). Dry AMD is managed with AREDS2 supplementation and risk-factor control; wet AMD is treated with intravitreal anti-VEGF injection.
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What this article covers
- Overview
Age-related macular degeneration (AMD) is a progressive disease of the central retina causing painless central vision loss and is a leading cause of irreversible blindness in older adults in resource-rich countries.
- Epidemiology
AMD is the most common cause of blindness in adults in resource-rich (developed) countries and a leading cause of irreversible blindness in the elderly; prevalence rises with advanced age.
- Risk factors
Advanced age is the strongest risk factor.
- Pathophysiology
Dry AMD begins with accumulation of drusen, extracellular lipid and protein deposits beneath the RPE, accompanied by RPE atrophy and clumps of pigment migrating into the retina, progressively compromising photoreceptor support.
- Clinical features
Painless, gradual loss of central vision is the hallmark presenting symptom of dry AMD, reflecting slow drusen accumulation and RPE atrophy.
- Differential diagnosis
Diabetic retinopathy: vision loss with a diabetes history; fundoscopy shows microaneurysms, dot-blot hemorrhages, and neovascularization rather than drusen.
- Diagnosis
AMD is a clinical diagnosis confirmed by dilated fundoscopic examination showing macular drusen with RPE change (dry) or subretinal fluid, hemorrhage, and choroidal neovascularization (wet).
- Management
First, stratify by form on fundoscopic exam and OCT, since dry and wet AMD are managed differently.
- Complications
Progressive central blindness is the end result of untreated advanced disease in either form, fastest with untreated wet AMD.
- Prognosis
Wet AMD, if untreated, is much more likely to progress to blindness than dry AMD and can do so within weeks to months, compared with years to decades for untreated dry AMD.
- Prevention
Screen with a comprehensive dilated eye examination every 1 to 2 years in older adults to detect drusen and pigmentary change before symptomatic vision loss.
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