Retinal Vessel Changes in Geographic Atrophy in AMD: Insights From Imaging and Histology

Area of Science:

• Ophthalmology
• Medical Imaging
• Histopathology

Background:

• Age-related macular degeneration (AMD) is a leading cause of vision loss.
• Geographic atrophy (GA) is an advanced form of AMD characterized by progressive retinal pigment epithelium (RPE) and photoreceptor cell loss.
• Understanding the vascular changes associated with GA is crucial for developing effective treatments.

Purpose of the Study:

• To investigate retinal vascular changes in geographic atrophy (GA) secondary to age-related macular degeneration (AMD) using swept-source optical coherence tomography angiography (SS-OCTA).
• To correlate SS-OCTA findings with histological data.
• To analyze the topographical distribution of vascular changes in relation to RPE atrophy.

Main Methods:

• Sixty subjects (20 with GA, 20 with intermediate AMD, 20 controls) underwent SS-OCTA.
• Quantification of retinal perfusion density (PD) and vessel length density (VLD) in superficial and deep capillary plexuses.
• Topographical analysis of vascular changes in regions with and without RPE atrophy.
• Histological analysis of a donor eye with GA.

Main Results:

• Retinal PD and VLD were significantly reduced in GA eyes compared to intermediate AMD and controls, especially in the deep capillary plexus.
• Vascular impairment was more pronounced in areas with RPE atrophy.
• Regions without RPE atrophy in GA eyes showed perfusion comparable to controls.
• Histology confirmed reduced vascular density in atrophic areas.

Conclusions:

• Retinal vascular changes in GA are predominantly localized within areas of RPE atrophy.
• Preserved perfusion in regions without RPE atrophy suggests localized vascular impairment.
• Regional analysis and histopathologic correlation are vital for understanding vascular remodeling in GA.
• Longitudinal SS-OCTA studies are needed to track temporal progression.