Optic Nerve Head Characteristics in Chronic Angle Closure Glaucoma Detected by Swept-Source OCT

Area of Science:

• Ophthalmology
• Glaucoma Research
• Optic Nerve Head Imaging

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Optic nerve head (ONH) structural abnormalities are key indicators of glaucoma progression.
• Differentiating structural pathologies between glaucoma subtypes is crucial for understanding disease mechanisms.

Purpose of the Study:

• To compare structural features of the prelaminar and laminar tissues of the optic nerve head (ONH).
• To investigate differences in ONH structural defects between chronic angle closure glaucoma (CACG), primary open angle glaucoma (POAG), and control subjects.

Main Methods:

• Swept-source optical coherence tomography (SS-OCT) was used for ONH imaging.
• Measurements included minimum rim width at Bruch's membrane opening (BMO-MRW) and lamina cribrosa depth (LCD).
• Prelaminar defects (holes, wedges) and lamina cribrosa (LC) defects were identified and characterized.

Main Results:

• Subjects with CACG and POAG showed significantly lower BMO-MRW compared to controls.
• Prelaminar holes were most frequent in the CACG group (65.0%) compared to POAG (25.0%) and controls (20.0%).
• CACG was associated with increased odds of prelaminar holes compared to POAG, with more holes per scan observed in CACG.

Conclusions:

• SS-OCT imaging revealed a higher prevalence of prelaminar holes in the ONH of CACG patients.
• These findings suggest distinct structural pathologies in the prelaminar region differentiating CACG from POAG and controls.
• Further research into these structural differences may inform targeted therapeutic strategies for CACG.