Choroidal Hyper-Reflective Foci in Geographic Atrophy

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Diseases

Background:

• Geographic atrophy (GA) is an advanced form of age-related macular degeneration (AMD).
• Optical coherence tomography (OCT) is a key imaging modality for visualizing retinal and choroidal structures.
• Choroidal hyper-reflective foci (HRF) are findings on OCT that require further characterization in various ocular conditions.

Purpose of the Study:

• To describe the presence and characteristics of choroidal hyper-reflective foci (HRF) using optical coherence tomography (OCT) in patients with geographic atrophy (GA).
• To investigate the relationship between choroidal HRF quantity and GA lesion size, as well as other clinical and imaging factors.

Main Methods:

• Retrospective analysis of 40 eyes from patients diagnosed with GA and age-related macular degeneration (AMD).
• Detailed review of OCT images to identify, characterize, and localize choroidal HRF.
• Quantification of choroidal HRF using two distinct methodologies: threshold reflectivity and manual counting.

Main Results:

• All analyzed eyes with GA exhibited multiple choroidal HRF in various layers, predominantly Sattler's layer, near Bruch's membrane or blood vessel edges.
• Choroidal HRF displayed variable size and shape, with some causing posterior shadowing or hypertransmission.
• A significant positive correlation was observed between the size of GA lesions and the number of choroidal HRF, irrespective of the quantification method used.

Conclusions:

• Structural OCT effectively identifies hyper-reflective dots in the choroid of GA patients.
• These choroidal HRF may represent intrinsic choroidal structures that become more apparent with the loss of retinal pigment epithelium in GA.