Which diagnostic tests are essential for confirming acute angle-closure glaucoma in a primary care setting?

In a primary care setting, the essential diagnostic tests to confirm acute angle-closure glaucoma include:

• Intraocular pressure (IOP) measurement using Goldmann-type applanation tonometry, as elevated IOP is a key indicator of angle-closure glaucoma.
• Peripheral anterior chamber configuration and depth assessment using gonioscopy, which is the definitive test to evaluate the angle closure. If gonioscopy is not available or feasible, the van Herick test or anterior segment optical coherence tomography (OCT) can be used as alternatives.
• Optic nerve head assessment and fundus examination using stereoscopic slit lamp biomicroscopy to detect optic nerve damage.

Non-contact tonometry alone should not be used to base referral decisions.

These tests help differentiate acute angle-closure glaucoma from other types of glaucoma and ocular conditions and guide urgent referral to ophthalmology services.

Note: Visual field testing and central corneal thickness measurement are important in chronic glaucoma diagnosis but are less critical in the acute angle-closure setting in primary care.

Immediate referral is warranted if clinical signs suggest acute angle closure.

NICE NG81