The anterior chamber angles in Nigerians

Area of Science:

• Ophthalmology
• Anatomy
• Public Health

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness globally.
• Understanding the anatomical variations in anterior chamber angles is crucial for glaucoma diagnosis and management, particularly in diverse populations.
• Previous studies suggest ethnic and geographic variations in glaucoma prevalence and risk factors.

Purpose of the Study:

• To investigate the anatomical configuration of anterior chamber angles in Nigerian adults with newly diagnosed primary glaucoma.
• To compare gonioscopic features and central anterior chamber depth (CACD) between glaucoma patients and a control group.
• To identify specific anatomical characteristics associated with primary glaucoma in the Nigerian adult population.

Main Methods:

• A comparative gonioscopic study was conducted on 240 Nigerian adults (≥30 years) with newly diagnosed primary glaucoma and 250 age- and sex-matched controls.
• Anterior chamber angles were graded using Scheie classification to assess angle width and identify closed angles (Scheie grade 0 or 1).
• Anterior iris insertion, trabecular meshwork pigmentation, peripheral iris curvature, and central anterior chamber depth (CACD) were evaluated.

Main Results:

• Significantly higher prevalence of closed angles (15.0% vs. 1.6%) and anterior iris insertion (14.2% vs. 3.2%) was observed in glaucoma patients compared to controls.
• Occludable angles were more frequent in the glaucoma group (38.8% vs. 10.4%).
• Mean central anterior chamber depth (CACD) was significantly shallower in glaucoma cases (P = 0.002), with shallower depths noted in females and decreasing with age.

Conclusions:

• Closed anterior chamber angles, anterior iris insertion, and shallower central anterior chamber depth are statistically significant risk factors associated with primary glaucoma in Nigerian adults.
• Trabecular meshwork pigmentation and peripherally convex iris curvature were not significantly associated with glaucoma in this cohort.
• These anatomical findings highlight the importance of gonioscopy and anterior segment evaluation in the early detection and management of glaucoma in this population.