Optic nerve head morphologic characteristics in chronic angle-closure glaucoma and normal-tension glaucoma

Area of Science:

• Ophthalmology
• Glaucoma Research
• Optic Nerve Imaging

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Distinguishing between different types of glaucoma, such as chronic angle-closure glaucoma (CACG) and normal-tension glaucoma (NTG), is crucial for effective management.
• Optic disk morphometry provides key insights into glaucoma pathophysiology.

Purpose of the Study:

• To compare the optic disk morphometric features between eyes with CACG and eyes with NTG.
• To identify specific structural differences that may aid in differentiating these glaucoma subtypes.

Main Methods:

• A retrospective, case-matched study design was employed.
• Patients with early to moderate stage CACG or NTG were included.
• Heidelberg retina tomography was used to analyze optic disk parameters, with matching based on age, sex, and visual field mean defect.

Main Results:

• The study included 20 matched pairs of eyes with CACG and NTG.
• Eyes with CACG exhibited significantly larger optic disk rim areas (total, temporal/inferior, nasal/superior, nasal/inferior) compared to NTG eyes (P<0.05).
• CACG eyes demonstrated significantly smaller optic cup volumes, mean cup depths, and cup shape measures across most sectors compared to NTG eyes (P values ranging from 0.002 to 0.041).

Conclusions:

• The morphometric characteristics of the optic disk are significantly different between eyes with CACG and NTG.
• These distinct optic disk features may serve as valuable biomarkers for differentiating between these glaucoma subtypes.