Anterior Segment OCT for Detection of Narrow Angles: A Community-Based Diagnostic Accuracy Study

Area of Science:

• Ophthalmology
• Medical Imaging
• Public Health

Background:

• Glaucoma is a leading cause of irreversible blindness globally.
• Early detection of narrow drainage angles is crucial for preventing angle-closure glaucoma.
• Anterior segment optical coherence tomography (AS-OCT) offers a non-contact method for angle assessment.

Purpose of the Study:

• To evaluate the diagnostic accuracy of AS-OCT in identifying gonioscopically narrow angles.
• To compare the performance of different AS-OCT parameters for angle assessment.
• To determine the utility of AS-OCT in a population-based screening setting.

Main Methods:

• A population-based cross-sectional study was conducted in Nepal.
• Individuals aged 60 years and older were recruited through a door-to-door census.
• Participants underwent AS-OCT, posterior segment OCT, and intraocular pressure (IOP) testing; those meeting referral criteria had gonioscopy performed by a specialist.

Main Results:

• The study included 12,633 participants aged 60+ years.
• Five AS-OCT parameters demonstrated good diagnostic ability for narrow angles (AUC 0.85-0.89).
• The angle opening distance at 750 μm (AOD750) showed optimal sensitivity (87%) and specificity (77%) at a 367 μm cutpoint, and 65% sensitivity at 90% specificity (283 μm cutpoint).

Conclusions:

• AS-OCT, particularly the AOD750 parameter, can effectively screen for gonioscopically narrow angles.
• While sensitivity may be insufficient for sole screening, AS-OCT provides incremental benefit when combined with posterior segment OCT.
• This technology holds potential for enhancing glaucoma screening programs in community settings.