Comparison of Structural and Functional Features in Primary Angle Closure and Open Angle Glaucomas

Area of Science:

• Ophthalmology
• Glaucoma Research
• Medical Imaging

Background:

• Glaucoma encompasses various subtypes, including primary angle closure glaucoma (PACG) and primary open-angle glaucoma (POAG).
• Understanding the distinct structural and functional characteristics of PACG and POAG is crucial for accurate diagnosis and management.
• Previous studies suggest potential differences, but large-scale comparative analyses are needed.

Purpose of the Study:

• To identify and compare the structural and functional differences between patients with PACG and POAG.
• To elucidate the specific patterns of damage in each glaucoma subtype.

Main Methods:

• A large cross-sectional study involving 283 patients with PACG and 4110 patients with POAG.
• Assessment of structural damage using optical coherence tomography (OCT).
• Evaluation of functional loss through reliable visual field testing.

Main Results:

• Despite similar visual field mean deviation, PACG patients exhibited thicker global retinal nerve fiber layer (RNFL), smaller cup volume, and larger rim area compared to POAG patients.
• POAG patients demonstrated more pronounced inferior RNFL thinning.
• PACG was associated with hyperopia and inferior visual field loss, while POAG was linked to superior paracentral loss.

Conclusions:

• Patients with PACG present with less structural damage but more inferiorly localized functional deficits compared to POAG patients, even with similar overall visual field severity.
• Recognizing these regional differences in structural and functional loss is vital for improving disease monitoring and management strategies for PACG and POAG.