The "diffuse-trickling" fundus autofluorescence phenotype in geographic atrophy

Area of Science:

• Ophthalmology
• Cardiology
• Genetics

Background:

• Geographic atrophy (GA) is an advanced form of age-related macular degeneration.
• Fundus autofluorescence (FAF) imaging reveals distinct patterns in GA phenotypes.
• The "diffuse-trickling" FAF pattern is a less understood GA subtype.

Purpose of the Study:

• To characterize the clinical and demographic features of the diffuse-trickling GA phenotype.
• To investigate potential systemic associations with this specific GA subtype.
• To explore ocular morphologic characteristics of diffuse-trickling GA.

Main Methods:

• Analysis of patients with diffuse-trickling GA from the Fundus Autofluorescence in Age-Related Macular Degeneration (FAM) Study.
• Characterization using FAF and spectral-domain optical coherence tomography (SD-OCT).
• Comparison of demographic data, medical history, and subfoveal choroidal thickness (SCT) with non-diffuse-trickling GA patients.

Main Results:

• Patients with diffuse-trickling GA were significantly younger at presentation (68.2 years) compared to other GA types (75.4 years).
• A higher prevalence of cardiovascular diseases, including myocardial infarction (MI), was observed in younger patients (<65 years) with diffuse-trickling GA.
• Significantly thinner subfoveal choroidal thickness (SCT) was found in diffuse-trickling GA (135.2 μm) versus non-diffuse-trickling GA (191.4 μm).

Conclusions:

• Diffuse-trickling GA is associated with systemic cardiovascular disorders, particularly in younger individuals.
• Ocular findings, including a lobular appearance and thin choroid, suggest impaired choroidal vascularization in this GA phenotype.
• This distinct GA phenotype may stem from vascular insufficiency within the choroid.