Quality statement 1: Referral – chronic open angle glaucoma and related conditions

Quality statement

Adults with signs of possible glaucoma or related conditions on a routine sight test have additional tests before they are referred for a diagnosis.

Rationale

Accurate diagnosis of chronic open angle glaucoma (COAG) or related conditions is important because they can lead to irreversible damage to the optic nerve and sight loss. As well as the routine sight test, additional tests are needed for people with possible glaucoma to support more accurate referrals for further investigation and diagnosis. They ensure that adults with COAG or related conditions have prompt diagnosis and treatment and people who do not need referral avoid unnecessary investigations.

Quality measures

Structure

a) Evidence of the availability of equipment for performing the additional tests needed before referral for further investigation and diagnosis of COAG or related conditions.

Data source: Local data collection, for example, service specifications.

b) Evidence of the availability of staff trained to perform the additional tests needed before referral for further investigation and diagnosis of COAG or related conditions.

Data source: Local data collection, for example, staff rotas and staff training records.

Process

Proportion of adults with signs of possible glaucoma on a routine sight test who had additional tests before referral for further investigation and diagnosis of COAG or related conditions.

Numerator – the number in the denominator who had additional tests before referral for further investigation and diagnosis of COAG or related conditions.

Denominator – the number of adults with signs of possible glaucoma on a routine sight test referred for further investigation and diagnosis of COAG or related conditions.

Data source: Local data collection, for example, patient records and referral records.

Outcome

Rates of false-positive referrals for further investigation and diagnosis of COAG or related conditions.

Data source: Local data collection, for example, patient records and referral records.

What the quality statement means for different audiences

Service providers (such as community optometry services) ensure that equipment, staff training and local referral pathways support adults with possible glaucoma to have additional tests after the routine sight test and before referral for further investigation and diagnosis of COAG or related conditions.

Healthcare professionals (such as community optometrists) ensure additional tests are performed when signs of possible glaucoma are detected on a routine sight test and refer on the basis of these results.

Commissioners (clinical commissioning groups and NHS England) ensure that services have agreed protocols and ensure service availability to support accurate referral into hospital eye services for adults with possible COAG or related conditions. They monitor referrals.

Adults with possible glaucoma have a range of tests after the routine sight test and before they are referred to hospital eye services. This means that only people needing further investigations are referred, which may reduce waiting times.

Source guidance

Glaucoma: diagnosis and management (2017) NICE guideline 81, recommendation 1.1.1

Definitions of terms used in this quality statement

Possible glaucoma or related conditions

Signs of possible glaucoma or related conditions include:

  • a glaucomatous-type visual field defect

  • visible structural damage to the optic nerve head

  • an intraocular pressure of 24 mmHg or more.

[Adapted from NICE's guideline on glaucoma, recommendation 1.1.5, and expert opinion]

Additional tests

If a routine sight test suggests signs of possible glaucoma, all of the following additional tests should be undertaken before referral:

  • central visual field assessment using standard automated perimetry (full threshold or supra‑threshold)

  • optic nerve assessment and fundus examination using stereoscopic slit lamp biomicroscopy (with pupil dilatation if necessary), and optical coherence tomography (OCT) or optic nerve head image if available

  • intraocular pressure measurement using Goldmann-type applanation tonometry

  • peripheral anterior chamber configuration and depth assessments using gonioscopy or, if not available or the person prefers, the van Herick test or OCT.

[NICE's guideline on glaucoma, recommendation 1.1.1]