The Inter-Eye Differences of the Circumpapillary Microvasculature in Primary Open-Angle Glaucoma

Area of Science:

• Ophthalmology
• Vascular Biology
• Glaucoma Research

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
• Understanding the vascular contributions to glaucomatous damage is crucial for developing effective treatments.
• Inter-eye asymmetry in ocular parameters is a characteristic feature of POAG.

Purpose of the Study:

• To evaluate inter-eye differences in circumpapillary vessel density (cpVD) in patients with POAG.
• To identify factors contributing to glaucomatous vascular pathology, particularly systemic influences.
• To compare cpVD asymmetry with retinal nerve fiber layer (RNFL) and visual field (VF) asymmetry in POAG.

Main Methods:

• Optical coherence tomography (OCT) and OCT angiography (OCTA) were performed on both eyes of POAG subjects and controls.
• Inter-eye differences in OCT, OCTA, VF, and other ophthalmic parameters were analyzed.
• Multivariable regression analysis was used to identify associations between asymmetries and clinical factors.

Main Results:

• POAG subjects exhibited greater inter-eye RNFL asymmetry (10 ± 10 µm) compared to controls (5 ± 5 µm).
• POAG patients showed significant visual field mean deviation (MD) asymmetry between eyes (-5.2 ± 4.0 dB vs. -1.5 ± 2.6 dB).
• Inter-eye cpVD asymmetry was similar between POAG subjects (3.5% ± 2.6%) and controls (3.1% ± 1.9%).
• MD asymmetry correlated with RNFL asymmetry, while treated systemic hypertension was linked to decreased cpVD asymmetry.

Conclusions:

• POAG is characterized by greater inter-eye asymmetry in RNFL thickness than in cpVD.
• RNFL asymmetry is associated with VF deficits.
• Systemic hypertension treatment appears to mitigate inter-eye differences in circumpapillary microvasculature, suggesting systemic factors influence glaucomatous vascular pathology.