Peripapillary and Macular Vessel Density in Patients with Glaucoma and Single-Hemifield Visual Field Defect

Area of Science:

• Ophthalmology
• Medical Imaging
• Glaucoma Research

Background:

• Open-angle glaucoma (OAG) is a leading cause of irreversible blindness.
• Early detection of glaucomatous damage is crucial for preserving vision.
• Optical coherence tomography angiography (OCT-A) offers high-resolution imaging of retinal vasculature.

Purpose of the Study:

• To compare hemifield differences in peripapillary and macular vessel density in OAG eyes with unilateral visual field (VF) defects.
• To assess the relationship between vessel density and VF loss using OCT-A.
• To evaluate OCT-A's potential for detecting early glaucomatous changes.

Main Methods:

• Cross-sectional study involving 58 OAG eyes with unilateral VF defects and 28 healthy eyes.
• OCT-A was used to measure circumpapillary vessel density (cpVD) and perifoveal vessel density (pfVD).
• Spectral domain optical coherence tomography (SD-OCT) measured circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (mGCC) thickness.

Main Results:

• Glaucoma eyes showed significantly lower cpVD and pfVD in both affected and intact hemiretinae compared to healthy eyes (P < 0.001).
• Vessel density in intact hemiretinae was reduced compared to healthy controls, indicating subclinical damage.
• cpVD demonstrated the strongest association with mean sensitivity (MS) in affected hemifields (r=0.707), followed by pfVD, cpRNFL, and mGCC.

Conclusions:

• Reduced peripapillary and macular vessel density is detectable in the intact hemiretinae of OAG eyes with unilateral VF defects.
• Vessel density reduction in both hemiretinae correlates with the severity of VF damage.
• OCT-A shows promise for identifying glaucomatous damage before it is evident in standard VF testing.