[Does the Foveal Avascular Zone Change in Glaucoma?]

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• The foveal avascular zone (FAZ) and surrounding vasculature are critical in glaucoma. Changes in FAZ characteristics (area, perimeter, acircularity index) and vessel density (VD) are investigated.
• Glaucoma's impact on ocular vasculature, particularly in the macula, is a key area of research. This study compares glaucomatous and healthy eyes, further subdividing glaucoma cases by visual field defect location.

Purpose of the Study:

• To compare FAZ parameters and parafoveal vessel density between healthy and glaucomatous eyes.
• To investigate how the location of visual field defects (central vs. peripheral) influences FAZ characteristics and VD in glaucoma patients.

Main Methods:

• Optical coherence tomography angiography (OCTA) was used to analyze data from 128 eyes (74 glaucoma, 54 healthy).
• FAZ area, perimeter, and acircularity index (AI), along with superficial and deep vascular plexus VD, were quantified.
• Glaucomatous eyes were categorized into those with central (ZGD) and peripheral (PGD) visual field defects.

Main Results:

• No significant differences in FAZ area, perimeter, or AI were found between all glaucomatous and healthy eyes.
• Glaucomatous eyes with central visual field defects (ZGD) exhibited significantly larger FAZ area and perimeter compared to those with peripheral defects (PGD).
• Macular/foveal vessel density (VD) was significantly lower in the ZGD group compared to the PGD group.

Conclusions:

• Glaucoma is associated with FAZ enlargement when visual field defects are centralized.
• A significant decrease in foveal vessel density is observed in glaucoma patients with central visual field defects.