Age-related macular degeneration (AMD) — geographic atrophy (GA) is characterized on fundus autofluorescence (FAF) as:

• A Increased autofluorescence (hyper-AF) with well-demarcated borders
• B Patchy hyper-AF and hypo-AF interspersed randomly
• C Normal autofluorescence with no FAF changes
• D Decreased autofluorescence (hypo-AF) with a hyper-AF rim at the edge of atrophy ✓

Explanation

In geographic atrophy of AMD, FAF imaging shows sharply demarcated areas of decreased autofluorescence (hypo-AF) corresponding to the loss of RPE cells and their lipofuscin content. A surrounding ring of increased AF (hyper-AF rim) is often present, representing stressed or degenerating RPE cells with excess lipofuscin accumulation at the border of atrophy — this hyper-AF junctional zone predicts GA progression. Drusen appear as hyper-AF on FAF. Subretinal fluid in wet AMD may show subtle hyper-AF changes.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.