What criteria should I use to determine the urgency of a referral for a patient with suspected glaucoma?

Criteria to determine the urgency of referral for suspected glaucoma:

• Refer urgently if there is evidence of optic nerve head damage on stereoscopic slit lamp biomicroscopy or a repeatable visual field defect consistent with glaucoma, or if intraocular pressure (IOP) is 24 mmHg or more measured by Goldmann-type applanation tonometry.
• Before referral, consider repeating visual field assessment and IOP measurement on another occasion to confirm abnormalities unless clinical circumstances indicate urgent or emergency referral is needed.
• Do not base referral urgency solely on IOP measured by non-contact tonometry.
• Referral should be to a consultant ophthalmologist or suitably trained healthcare professional for definitive diagnosis and management planning if suspected optic nerve damage or visual field defect is present.
• Clinical judgment should be used to determine urgency, considering the severity of findings and risk of sight loss.

Provide all examination and test results with the referral to aid specialist assessment.

People with IOP below 24 mmHg without other signs should continue regular monitoring by primary eye care professionals rather than urgent referral.

Urgency is generally not immediate emergency but should be timely to prevent progression of sight loss.

Summary: Urgent referral is indicated by confirmed optic nerve damage, visual field defects, or IOP ≥24 mmHg on Goldmann applanation tonometry; otherwise, repeat testing and clinical judgment guide referral timing.

NICE NG81