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This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.
The Bottom Line
- AMD causes painless central vision loss; peripheral vision is usually preserved
- Dry AMD: drusen and retinal pigment epithelium changes; geographic atrophy in advanced disease
- Wet AMD: choroidal neovascularization with subretinal fluid/hemorrhage — rapid distortion or central vision decline
- First-line treatment for wet AMD: intravitreal anti-VEGF therapy
- AREDS2 vitamins reduce progression risk in intermediate AMD but do not prevent AMD in low-risk patients
Overview
Age-related macular degeneration (AMD) is a chronic degenerative disease of the macula and retinal pigment epithelium that impairs sharp central vision. It is classified as non-neovascular (dry) or neovascular (wet). Dry AMD is more common and progresses slowly through drusen accumulation, pigmentary abnormalities, and sometimes geographic atrophy. Wet AMD is less common but accounts for most severe acute central vision loss because choroidal neovascular membranes leak blood and fluid beneath or within the retina.
Epidemiology
AMD is a leading cause of irreversible central vision loss in older adults in the United States. Prevalence increases markedly after age 65. Major risk factors include age, cigarette smoking, family history, White ancestry, cardiovascular disease, hypertension, hyperlipidemia, and low dietary intake of antioxidant-rich foods. Smoking is the most important modifiable risk factor and also affects formulation choice because beta-carotene increases lung cancer risk in current and former smokers.
Clinical Features
Symptoms
Painless central blurring or difficulty reading, recognizing faces, or seeing fine detail
Metamorphopsia: straight lines look wavy or distorted — suggests wet AMD
Central scotoma with preserved peripheral navigation
Rapid central vision loss over days to weeks suggests neovascular AMD
No eye pain, redness, or photophobia unless another diagnosis is present
Signs
Drusen: yellow extracellular deposits under the retina
Retinal pigment epithelial mottling or atrophy
Geographic atrophy with sharply demarcated RPE loss in advanced dry AMD
Subretinal fluid, hemorrhage, lipid exudates, or gray-green neovascular membrane in wet AMD
Abnormal Amsler grid with distortion or missing central lines
Investigations
First-line
Dilated fundus examinationIdentifies drusen, pigment changes, geographic atrophy, hemorrhage, exudates, or subretinal fluid
Amsler gridSimple functional test for metamorphopsia; new distortion requires urgent ophthalmology review
Visual acuity assessmentDocuments baseline and monitors functional impact
Second-line
Optical coherence tomography (OCT)Key imaging test. Shows drusen, retinal pigment epithelial detachment, intraretinal/subretinal fluid, and geographic atrophy
Fluorescein angiographyDemonstrates choroidal neovascular leakage when diagnosis or treatment planning is uncertain
OCT angiographyNoninvasive assessment of neovascular membranes; increasingly used alongside structural OCT
Specialist
Retina specialist evaluationNeeded urgently for suspected wet AMD because anti-VEGF therapy is time-sensitive
Low-vision assessmentFor advanced bilateral disease: magnification, contrast tools, reading aids, and rehabilitation
1
Dry AMD
- Smoking cessation — the most important modifiable intervention
- AREDS2 formulation for intermediate AMD or advanced AMD in one eye: vitamin C, vitamin E, zinc, copper, lutein, and zeaxanthin
- Avoid beta-carotene-containing formulas in current or former smokers
- Home Amsler grid monitoring and urgent reporting of new distortion or central scotoma
- Optimize cardiovascular risk factors and encourage a diet rich in leafy green vegetables and fish
2
Wet AMD
- Urgent retina referral for intravitreal anti-VEGF therapy
- Anti-VEGF options include ranibizumab, aflibercept, bevacizumab, brolucizumab, and faricimab depending on local practice and patient factors
- OCT-guided treatment interval: monthly loading followed by fixed, treat-and-extend, or PRN regimens
- Educate about injection complications: endophthalmitis symptoms include pain, severe redness, photophobia, and decreased vision
3
Geographic atrophy
- Monitor for progression and conversion to neovascular AMD
- Complement inhibitors may slow geographic atrophy progression in selected patients but do not restore lost vision
- Discuss treatment burden, inflammation risk, and patient goals with retina specialist
4
Functional support
- Low-vision rehabilitation for advanced central vision loss
- Fall-risk mitigation, driving assessment, reading aids, occupational support, and depression screening when vision loss affects independence
Complications
- Severe central vision loss: Reading and face recognition become impaired while peripheral vision often persists
- Choroidal neovascular bleeding: Sudden central scotoma or distortion in wet AMD
- Geographic atrophy: Progressive enlargement of atrophic macular lesions in dry AMD
- Anti-VEGF complications: Endophthalmitis, transient IOP rise, intraocular inflammation, and rare retinal tear/detachment
- Functional decline: Falls, driving cessation, social isolation, and depression
USMLE Step 2 CK Exam Tips
- 1Older patient + painless central vision loss + drusen = age-related macular degeneration
- 2Wet AMD is suggested by metamorphopsia, subretinal hemorrhage, fluid, or rapid decline — treat with intravitreal anti-VEGF
- 3Dry AMD is more common; wet AMD causes more severe rapid vision loss
- 4AREDS2 reduces progression in intermediate AMD; it does not reverse disease or prevent AMD in everyone
- 5Peripheral vision is preserved in AMD; glaucoma causes peripheral field loss first
- 6Amsler grid distortion is a classic clue for macular pathology
- 7Beta-carotene should be avoided in smokers/former smokers because of lung cancer risk
- 8Cataracts cause glare and cloudy lens; AMD causes macular drusen and central scotoma
practicetest your knowledge on age-related macular degenerationApply what you've learnt with USMLE Step 2 CK-style questions from the iatroX Q-Bank — ophthalmology and beyond.
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