Updated glaucoma guidance raises IOP benchmark

New glaucoma guidance from the National Institute for Health and Care Excellence (NICE) has increased the threshold for referral from an inner eye pressure of 22 mmHg to 24mmHg.

A statement from NICE accompanying the release of the updated guidance explained that the raised benchmark better represented the population at “greatest risk” of going on to develop chronic open angle glaucoma (COAG).

“It is now recommended that people with an inner eye pressure below 24mmHg should continue regular visits to their primary eye care professional so any future increase in pressure is detected,” the statement continued.

Professor Mark Baker, NICE’s director of the centre for guidelines, highlighted that around 1.8 million people in the UK have an inner eye pressure of 22 or 23mmHg.

“Increasing the treatment threshold will not only lead to fewer patients being referred unnecessarily but it should reduce costs without compromising patient safety,” Professor Baker emphasised.

The new guidelines include a section on what tests should be carried out by primary eye care professionals to determine if referral to a specialist is necessary.

Referral may be based on the presence of optic nerve head damage, a visual field defect consistent with glaucoma or an inner eye pressure of 24mmHg or more using Goldmann-type applanation tonometry.

The guidelines emphasise that clinicians should not make a referral solely on the basis of inner eye pressure measured through non-contact tonometry.

The guidance also highlights that repeat measures of visual field and inner eye pressure should be considered unless the clinical circumstances indicate the need for an urgent referral.

Moorfields Eye Hospital consultant ophthalmologist, Professor Paul Foster, highlighted that raising the referral threshold would have a minimal impact on the detection of sight-threatening glaucoma while reducing the number of unnecessary hospital referrals by 69%.

“This will allow patients with sight-threatening conditions to be seen more urgently, and patients given more time for detailed examinations, discussions and planning of care at diagnosis,” he emphasised.

Professor Foster elaborated that the EPIC-Norfolk observational study of more than 8600 participants found 76% of undiagnosed cases of eye disease had normal eye pressure, meaning that they would not have been detected by assessment of eye pressure alone.

“Other methods of detecting glaucoma, including visual field testing and examination of the optic nerve, should form the basis for referral to the hospital eye service,” he observed.