What is the most likely diagnosis for a 70-year-old man with worsening vision over the past few months, uncorrected by over-the-counter reading glasses, and presenting with age-related symptoms?

Age-Related Macular Degeneration

Based on the clinical presentation of a 70-year-old man with progressive vision loss over months that is not correctable with reading glasses, age-related macular degeneration (AMD) is the most consistent diagnosis among the options provided. 1, 2

Clinical Reasoning

Patient Demographics and Risk Profile

• Age is the primary risk factor: AMD generally occurs in persons over age 65, with prevalence increasing from 1% in those aged 65-69 years to 17% in those older than 80 years 1
• This 70-year-old patient falls squarely within the high-risk age group for AMD 1, 3
• The 20-year absence from healthcare increases likelihood of undiagnosed chronic conditions like AMD 2

Symptom Pattern Analysis

• Progressive vision loss over months is characteristic of AMD, which can progress slowly and may be difficult for older adults to recognize, especially with comorbid conditions 1
• Failure of reading glasses to correct vision indicates the problem is not simple refractive error but rather macular pathology affecting central vision 4
• AMD causes progressive central vision loss while peripheral vision remains intact, distinguishing it from other conditions 4, 5

Differential Diagnosis Considerations

Why NOT the other options:

• Branch retinal artery occlusion: Presents with sudden, painless vision loss (not gradual over months) and would show characteristic fundoscopic findings of retinal whitening in the affected vascular distribution [@general medical knowledge@]

• Open-angle glaucoma: Causes peripheral vision loss first, not central vision problems that would interfere with reading; progression is typically very slow and asymptomatic until advanced stages [@general medical knowledge@]

• Retinitis pigmentosa: Hereditary condition that typically presents earlier in life with night blindness and peripheral vision loss ("tunnel vision"), not central vision loss in a 70-year-old [@general medical knowledge@]

• Diabetic retinopathy: While possible given the patient's lack of healthcare, the question stem does not mention diabetes history, and the age-specific presentation strongly favors AMD 1

Epidemiological Support

• AMD affects an estimated 1.8 million older adults in the United States and is the leading cause of severe vision loss and legal blindness in elderly populations 1, 4
• Approximately 1.75 million people aged 40+ have either neovascular AMD or geographic atrophy in at least one eye 2
• More than 9 million individuals are thought to have some form of AMD 4

Clinical Implications

Immediate Next Steps

• Comprehensive dilated fundoscopic examination is required to confirm diagnosis and classify AMD type (dry vs. wet) 3, 6
• Look for drusen (yellow deposits in the retina) as early findings on ophthalmoscopic examination 4
• Optical coherence tomography (OCT) should be performed to evaluate for subretinal fluid, intraretinal fluid, or geographic atrophy 1, 2

Critical Management Considerations

• Early detection is crucial: Early treatment of wet AMD within 2 years of diagnosis significantly reduces legal blindness and visual impairment 2
• If wet AMD is diagnosed, intravitreal anti-VEGF therapy (aflibercept, ranibizumab, or bevacizumab) should be initiated immediately with three loading doses at 4-week intervals 1, 2, 7
• For intermediate or advanced AMD, AREDS2 supplementation can reduce progression risk by up to 36% over 10 years 2

Common Pitfall

The most critical error would be attributing the vision changes to normal aging or simple refractive error and delaying ophthalmologic referral, as this patient requires urgent evaluation to determine if wet AMD is present, which demands immediate anti-VEGF treatment to prevent irreversible vision loss 2.