Recommendations

People have the right to be involved in discussions and make informed decisions about their care, as described in your care.

Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

1.1 Case-finding

The recommendations on case-finding are for primary eye care professionals before referral for diagnosis of chronic open angle glaucoma (COAG) and related conditions, and are separate from a sight test.

1.1.1 Before referral for further investigation and diagnosis of COAG and related conditions, offer all of the following tests:

  • 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 (IOP) measurement using Goldmann-type applanation tonometry

  • peripheral anterior chamber configuration and depth assessments using gonioscopy or, if not available or the patient prefers, the van Herick test or OCT. [2017]

1.1.2 Do not base a decision to refer solely on IOP measurement using non-contact tonometry. [2017]

1.1.3 Do not refer people who have previously been discharged from hospital eye services after assessment for COAG and related conditions unless clinical circumstances have changed and a new referral is needed. [2017]

1.1.4 Before deciding to refer, consider repeating visual field assessment and IOP measurement on another occasion to confirm a visual field defect or IOP of 24 mmHg or more, unless clinical circumstances indicate urgent or emergency referral is needed. [2017]

1.1.5 Refer for further investigation and diagnosis of COAG and related conditions, after considering repeat measures as in recommendation 1.1.4, if:

  • there is optic nerve head damage on stereoscopic slit lamp biomicroscopy or

  • there is a visual field defect consistent with glaucoma or

  • IOP is 24 mmHg or more using Goldmann-type applanation tonometry. [2017]

1.1.6 Provide results of all examinations and tests with the referral. [2017]

1.1.7 Advise people with IOP below 24 mmHg to continue regular visits to their primary eye care professional. [2017]

These recommendations are for people planning and providing eye care services before referral

1.1.8 People planning and providing eye care services should use a service model that includes Goldmann-type applanation tonometry before referral for diagnosis of COAG and related conditions. [2017]

1.1.9 People planning eye care services should consider commissioning referral filtering services (for example, repeat measures, enhanced case-finding, or referral refinement) for COAG and related conditions. [2017]

1.2 Diagnosis

1.2.1 To diagnose COAG and related conditions, offer all of the following tests:

  • visual field assessment using standard automated perimetry (central thresholding test), repeated if necessary to establish severity at diagnosis

  • optic nerve assessment and fundus examination using stereoscopic slit lamp biomicroscopy, with pupil dilatation

  • IOP measurement using Goldmann applanation tonometry (slit lamp mounted)

  • peripheral anterior chamber configuration and depth assessments using gonioscopy

  • central corneal thickness (CCT) measurement. [2017]

1.2.2 Adopt professional[1]/Department of Health[2] guidance to reduce the risk of transmitting infective agents via contact tonometry or gonioscopy. [2009]

1.2.3 Use the van Herick peripheral anterior chamber depth assessment if clinical circumstances rule out gonioscopy (for example, when people with physical or learning disabilities are unable to participate in the examination). [2009]

1.2.4 Obtain an optic nerve head image at diagnosis for baseline documentation (for example, a stereoscopic optic nerve head image or OCT). [2009, amended 2017]

1.2.5 After referral, consider an early assessment appointment when there is clinical concern based on the information provided. [2017]

1.2.6 At the time of diagnosis of ocular hypertension (OHT), assess risk of future visual impairment, taking account of risk factors such as:

  • level of IOP

  • CCT

  • family history

  • life expectancy. [2017]

1.3 Standard practice for all assessments

1.3.1 Ensure that all of the following are made available at each clinical episode to all healthcare professionals involved in a person's care:

  • records of all previous tests and images relevant to COAG and OHT assessment

  • records of past medical history which could affect drug choice

  • current systemic and topical medication

  • glaucoma medication record

  • drug allergies and intolerances. [2009]

1.3.2 Use alternative methods of assessment if clinical circumstances rule out standard methods (for example, when people with physical or learning disabilities are unable to participate in the examination). [2009]

1.3.3 Ensure that all machines and measurement instruments are calibrated regularly according to the manufacturers' instructions. [2009]

1.4 Reassessment

Reassessment tests

1.4.1 At each assessment, offer the following tests to people with COAG, people suspected of having COAG and people with OHT:

  • Goldmann applanation tonometry (slit lamp mounted)

  • anterior segment slit lamp examination with van Herick peripheral anterior chamber depth assessment when clinically indicated. [2017]

1.4.2 When clinically indicated, repeat gonioscopy, for example, where a previous examination has been inconclusive or where there is suspicion of a change in clinical status of the anterior chamber angle. [2017]

1.4.3 When clinically indicated, repeat visual field testing using standard automated perimetry (central thresholding test) for people with COAG and those suspected of having visual field defects who are being investigated for possible COAG (see tables 2 and 3 for recommended reassessment intervals). [2009, amended 2017]

1.4.4 When clinically indicated, repeat visual field testing using either a central thresholding test or a supra-threshold test for people with OHT and those suspected of having COAG whose visual fields have previously been documented by standard threshold automated perimetry (central thresholding test) as being normal (see tables 1 and 2 for recommended reassessment intervals). [2009, amended 2017]

1.4.5 When a visual field defect has previously been detected, use the same measurement strategy for each visual field assessment. [2009]

1.4.6 When clinically indicated, repeat assessment of the optic nerve head (for example, stereoscopic slit lamp biomicroscopy or imaging). [2017]

1.4.7 When a change in optic nerve head status is detected by stereoscopic slit lamp biomicroscopy, obtain a new optic nerve head image for the person's records to provide a fresh benchmark for future assessments. [2009]

1.4.8 When an adequate view of the optic nerve head and surrounding area is unavailable at reassessment, people should have their pupils dilated before stereoscopic slit lamp biomicroscopy or optic nerve head imaging is repeated. [2009]

When to reassess

People with COAG, suspected COAG and OHT

1.4.9 At each assessment, re-evaluate risk of conversion to COAG and risk of sight loss to set time to next assessment. [2017]

1.4.10 At each assessment, ask about general health and, if appropriate, factors affecting adherence to treatment, including cognitive impairment and any treatment side effects. [2017]

People with treated OHT (baseline IOP 24 mmHg or more) and a normal optic nerve head and visual field at most recent assessment

1.4.11 For people with treated OHT (baseline IOP of 24 mmHg or more) and a normal optic head and visual field at the most recent assessment:

  • use clinical judgement to assess control of IOP and risk of conversion to COAG, and

  • reassess according to table 1. [2017]

Table 1 Time to next assessment for people being treated for OHT

Conversion from OHT to COAG

Control of IOP

Time to next assessment 1

Not detected or uncertain conversion2

No

Review management plan and reassess between 1 and 4 months

Uncertain conversion2

Yes

Reassess between 6 and 12 months

No conversion detected

Yes

Reassess between 18 and 24 months

Conversion

No or yes

See recommendations on the diagnosis and reassessment of COAG

1 Use clinical judgement to decide when the next appointment should take place within the recommended interval.

2 Uncertain conversion includes having insufficient accurate information (perhaps because the person was unable to participate in the assessment).

People with suspected COAG

1.4.12 For people with suspected COAG:

  • use clinical judgement to assess control of IOP and risk of conversion to COAG (optic nerve head damage and visual field defect), and

  • reassess according to table 2. [2017]

Table 2 Time to next assessment for people with suspected COAG

Conversion to COAG

Control of IOP

Time to next assessment 1

Not detected or uncertain conversion2

No

Review management plan and reassess between 1 and 4 months

Uncertain conversion2

Yes

Reassess between 6 and 12 months

No conversion detected

Yes

Reassess between 12 and 18 months

Conversion

No or yes

See recommendations on the diagnosis and reassessment of COAG

1 Use clinical judgement to decide when the next appointment should take place within the recommended interval.

2 Uncertain conversion includes having insufficient accurate information (perhaps because the person was unable to participate in the assessment).

People with COAG

1.4.13 For people with COAG:

  • use clinical judgement to assess risk of COAG progression to sight loss, and

  • reassess according to table 3. [2017]

Table 3 Time to next assessment for people with COAG

Progression of COAG

Control of IOP

Time to next assessment 1

Not detected

No

Review treatment plan and reassess between 1 and 4 months

Uncertain progression2 or progression

No

Review treatment plan and reassess between 1 and 2 months

No progression detected and low clinical risk

Yes

Reassess between 12 and 18 months

No progression detected and high clinical risk

Yes

Reassess between 6 and 12 months

Uncertain progression2 or progression

Yes

Review treatment plan and reassess between 2 and 6 months

1 Use clinical judgement to decide when the next appointment should take place within the recommended interval.

2 Uncertain progression includes having insufficient accurate information (perhaps because the person was unable to participate in the assessment).

Discharge back to primary care

1.4.14 Discharge people back to primary eye care services if:

  • they were referred for OHT but do not need treatment

  • they were referred for suspected COAG but this is no longer suspected.

    Advise people that they should continue with regular visits to their primary eye care professional, at clinically appropriate intervals. [2017]

1.4.15 Give a discharge summary to people who have been assessed and discharged to primary care. Send a copy to their GP and, with patient consent, copy the relevant information to the primary eye care professional nominated by the patient. Advise people to take their discharge summary with them when attending future sight tests. [2017]

1.5 Treatment

1.5.1 Take into account any cognitive and physical impairments when making decisions about management and treatment. [2017]

1.5.2 Check that there are no relevant comorbidities or potential drug interactions before offering pharmacological treatment. [2009]

Treatment for people with OHT

1.5.3 Offer a generic prostaglandin analogue (PGA)[3] to people with IOP of 24 mmHg or more (OHT) if they are at risk of visual impairment within their lifetime (see recommendation 1.2.6). [2017]

1.5.4 Do not offer treatment to people with OHT who are not at risk of visual impairment in their lifetime. Advise people to continue regular visits to their primary eye care professional, at clinically appropriate intervals. [2017]

1.5.5 Offer another pharmacological treatment to people with an IOP of 24 mmHg or more who cannot tolerate their current treatment. The first choice should be an alternative generic PGA, if available, and if this is not tolerated, offer a beta‑blocker. If none of these options are tolerated, offer non-generic PGA, carbonic anhydrase inhibitors, sympathomimetics, miotics or a combination of treatments. [2017]

1.5.6 Offer a drug from another therapeutic class (beta-blocker, carbonic anhydrase inhibitor[4] or sympathomimetic) to people with an IOP of 24 mmHg or more whose current treatment is not reducing IOP sufficiently to prevent the risk of progression to sight loss. Topical drugs from different therapeutic classes may be needed at the same time to control IOP. [2009, amended 2017]

1.5.7 Refer people whose IOP cannot be reduced sufficiently with pharmacological treatment to prevent the risk of progression to sight loss to a consultant ophthalmologist to discuss other options. [2009]

1.5.8 Offer preservative-free eye drops to people who have an allergy to preservatives or people with clinically significant and symptomatic ocular surface disease, but only if they are at high risk of conversion to COAG. [2009, amended 2017]

Treatment for people with suspected COAG

1.5.9 Do not offer treatment to people with suspected COAG and IOP less than 24 mmHg. Advise people to continue regular visits to their primary eye care professional, at clinically appropriate intervals. [2017]

1.5.10 Offer a generic PGA[3] to people with suspected COAG and IOP of 24 mmHg or more, in line with the recommendations on treatment for people with OHT. [2017]

Stopping treatment for people with OHT or suspected COAG

1.5.11 Discuss the benefits and risks of stopping treatment with people with OHT or suspected COAG who have both:

  • a low risk of ever developing visual impairment within their lifetime

  • an acceptable IOP.

    If a person decides to stop treatment after this discussion, offer to assess their IOP in 1 to 4 months with further reassessment if clinically indicated. [2009]

Treatment for people with COAG

1.5.12 Offer a generic PGA[3] to people with COAG. [2017]

1.5.13 Offer people with advanced COAG, surgery with pharmacological augmentation (MMC[5]) as indicated. Offer them information on the risks and benefits associated with surgery. [2009, amended 2017]

1.5.14 Offer people who present with advanced COAG and who are listed for surgery, interim treatment with a generic PGA[3]. [2009, amended 2017]

1.5.15 Encourage people to continue with the same pharmacological treatment unless:

  • their IOP cannot be reduced sufficiently to prevent the risk of progression to sight loss

  • there is progression of optic nerve head damage

  • there is progression of visual field defect

  • they cannot tolerate the drug. [2009]

1.5.16 Ask about adherence to treatment and check the eye drop instillation technique in people with COAG whose IOP has not been reduced sufficiently to prevent the risk of progression to sight loss despite pharmacological treatment. If adherence and eye drop instillation technique are satisfactory offer 1 of the following:

  • a drug from another therapeutic class (a beta-blocker, carbonic anhydrase inhibitor[4] or sympathomimetic); topical drugs from different therapeutic classes may be needed at the same time to control IOP

  • laser trabeculoplasty

  • surgery with pharmacological augmentation (MMC[5]) as indicated.

    If the drug treatment option is chosen, after trying drugs from 2 therapeutic classes, consider offering surgery with pharmacological augmentation (MMC[5]) as indicated or laser trabeculoplasty. [2009, amended 2017]

1.5.17 Offer surgery with pharmacological augmentation (MMC[5]) as indicated to people with COAG who are at risk of progressing to sight loss despite treatment. Offer them information on the risks and benefits associated with surgery. [2009, amended 2017]

1.5.18 Consider offering people with COAG who cannot tolerate a treatment:

  • a drug from another therapeutic class (a beta-blocker, carbonic anhydrase inhibitor[4] or sympathomimetic) or

  • preservative-free eye drops if there is evidence that the person is allergic to the preservative or has clinically significant and symptomatic ocular surface disease.

    After trying drugs from 2 therapeutic classes, consider offering surgery with pharmacological augmentation (MMC[5]) as indicated or laser trabeculoplasty. [2009, amended 2017]

1.5.19 After surgery offer people with COAG whose IOP has not been reduced sufficiently to prevent the risk of progression to sight loss 1 of the following:

  • pharmacological treatment; topical drugs from different therapeutic classes may be needed at the same time to control IOP

  • further surgery

  • laser trabeculoplasty or cyclodiode laser treatment. [2009, amended 2017]

1.5.20 Offer people with COAG who prefer not to have surgery or for whom surgery is not suitable:

  • pharmacological treatment; topical drugs from different therapeutic classes may be needed at the same time to control IOP

  • laser trabeculoplasty or cyclodiode laser treatment. [2009, amended 2017]

1.6 Organisation of care

1.6.1 Refer people with suspected optic nerve damage or repeatable visual field defect, or both, to a consultant ophthalmologist for consideration of a definitive diagnosis and formulation of a management plan. [2009]

1.6.2 Diagnosis of OHT and suspected COAG and formulation of a management plan should be made by a suitably trained healthcare professional with:

  • a specialist qualification and

  • relevant experience. [2009, amended 2017]

1.6.3 Be aware that holding an independent or non-medical prescribing qualification alone (without a specialist qualification relevant to the case complexity of glaucoma being managed) is insufficient for managing glaucoma and related conditions. [2017]

1.6.4 Healthcare professionals involved in the diagnosis of OHT and COAG suspect status and preliminary identification of COAG should be trained in case detection and referral refinement and be able to identify abnormalities based on relevant clinical tests and assessments. They should understand the principles of diagnosis of OHT and COAG and be able to perform and interpret all of the following:

  • medical and ocular history

  • differential diagnosis

  • Goldmann applanation tonometry (slit lamp mounted)

  • standard automated perimetry (central thresholding test)

  • central supra-threshold perimetry

  • stereoscopic slit lamp biomicroscopic examination of anterior segment

  • examination of the posterior segment using a slit lamp binocular indirect ophthalmoscopy

  • gonioscopy

  • van Herick peripheral anterior chamber depth assessment

  • CCT measurement. [2009]

1.6.5 People with OHT, suspected COAG or COAG should have monitoring and treatment from a trained healthcare professional who has all of the following:

  • a specialist qualification

  • relevant experience

  • ability to detect a change in clinical status. [2009, amended 2017]

1.6.6 Healthcare professionals involved in the monitoring and treatment of OHT, suspected COAG and established COAG should be trained to make management decisions on all of the following:

  • risk factors for conversion to COAG

  • coexisting pathology

  • risk of sight loss

  • monitoring and detecting a change in clinical status (for example, visual field changes, stereoscopic slit lamp biomicroscopic examination of anterior segment and posterior segment)

  • pharmacology of IOP-lowering drugs

  • treatment changes for COAG, suspected COAG and OHT (with consideration given to relevant contraindications and interactions). [2009]

1.6.7 People with a confirmed diagnosis of OHT or suspected COAG and who have an established management plan may have monitoring (but not treatment) from a suitably trained healthcare professional with knowledge of OHT and COAG, relevant experience and ability to detect a change in clinical status. The healthcare professional should be able to perform and interpret all of the following:

  • Goldmann applanation tonometry (slit lamp mounted)

  • standard automated perimetry (central thresholding test)

  • central supra-threshold perimetry (this visual field strategy may be used for monitoring OHT or suspected COAG when the visual field is normal)

  • stereoscopic slit lamp biomicroscopic examination of the anterior segment

  • van Herick peripheral anterior chamber depth assessment

  • examination of the posterior segment using slit lamp binocular indirect ophthalmoscopy. [2009]

1.6.8 Healthcare professionals who diagnose, treat or monitor independently of consultant ophthalmologist supervision should take full responsibility for the care they provide. [2009]

1.7 Providing information

1.7.1 Offer people the opportunity to discuss their diagnosis, referral, prognosis, treatment and discharge, and provide them with relevant information in an accessible format at initial and subsequent visits. This may include information on the following:

  • their specific condition (OHT, suspected COAG and COAG), its life-long implications and their prognosis for retention of sight

  • that COAG in the early stages and OHT and suspected COAG are symptomless

  • that most people having treatment for COAG will have good quality of life and not go blind

  • that once lost, sight cannot be recovered

  • that glaucoma can run in families and that family members may wish to be tested for the condition

  • the importance of the person's role in their own treatment – for example, the ongoing regular application of eye drops to preserve sight

  • the different types of treatment options, including mode of action, frequency and severity of side effects, and risks and benefits of treatment, so that people are able to take an active part in decision-making (see NICE's guideline on medicines optimisation)

  • how to apply eye drops, including technique (punctal occlusion and devices) and hygiene (storage)

  • the need for regular monitoring as specified by the healthcare professional

  • methods of investigation during assessment

  • how long each appointment is likely to take and whether the person will need any help to attend (for example, driving soon after pupil dilatation would be inadvisable)

  • the eye clinic liaison officer (ECLO)

  • support organisations and support groups

  • compliance aids (such as dispensers) available from their GP or community pharmacist

  • Letter of Vision Impairment (LVI), Referral of Vision Impairment (RVI) and Certificate of Vision Impairment (CVI), registration

  • Driver and Vehicle Licensing Agency (DVLA) regulations. [2009, amended 2017]

Terms used in this guideline

COAG and related conditions

These include COAG, OHT and suspected COAG.

Enhanced case-finding

Enhanced community case-finding services use slit lamp mounted Goldmann-type applanation tonometry, dilated slit lamp indirect biomicroscopy and other tests deemed necessary by the healthcare professional.

Hospital-based triage

A hospital-based risk assessment shortly after referral. Initial tests are performed to determine what happens next. For example, people at a low risk following initial testing by a nurse or technician may be discharged whereas those at higher risk may be directed to a more senior member of the assessment and diagnostic team, such as a consultant ophthalmologist.

Primary eye care professionals

These include optometrists, GPs with a special interest in ophthalmology and community orthoptists.

Referral filtering

A general term for any type of accuracy checking before referral to hospital eye services. Referral filtering may take the form of 'repeat measures', 'enhanced case-finding', 'referral refinement', 'hospital-based triage' or 'administrative paper-based triage'.

Referral refinement

A 2-tier assessment in which initial evidence of abnormality found during case-finding or screening is validated by an enhanced assessment, which adds value beyond that achieved through a simple 'repeat measures' scheme. A referral refinement service performs tests to diagnose OHT and suspected COAG and interprets the results in the light of clinical findings. Specialist practitioners who deliver this service independently have the qualifications and experience set out in the recommendations on organisation of care. Practitioners providing a referral refinement service should be qualified to make a diagnosis of OHT and suspected glaucoma, and to carry out gonioscopy to exclude angle-closure glaucoma.

Repeat measures

The repeated measurement of parameters related to the diagnosis of glaucoma. A simple repeat measures scheme may involve repeat measurement of IOP only. Other repeat measures schemes may also include repeated measurement of visual fields and other relevant ocular parameters when clinically necessary.

Sight loss

Sight loss in glaucoma is visual damage that manifests as blind spots in the field of vision. Early on these are mostly asymptomatic with many people being unware of a problem. Sight loss may progress to visual impairment and eventually become symptomatic.

Sight test

A sight test determines whether or not a person has a sight defect, and if so what is needed to correct, remedy or relieve it. An optometrist performing a sight test has to conduct the examinations specified in the Sight Testing (Examination and Prescription) (No 2) Regulations 1989. These include an internal and external examination of the eyes and any other examinations needed to detect signs of injury, disease or abnormality in the eye or elsewhere.

Visual impairment

A severe reduction in vision, which cannot be corrected with standard glasses or contact lenses and reduces a person's ability to function in a visual environment.



[1] See Royal College of Ophthalmologists' Ophthalmic Services Guidance.

[3] At the time of publication (November 2017), not all generic PGAs had a UK marketing authorisation for first-line treatment. The prescriber should follow relevant professional guidance, taking full responsibility for the decision. Informed consent should be obtained and documented. See the General Medical Council's Prescribing guidance: prescribing unlicensed medicines for further information.

[4] At the time of publication (November 2017), some carbonic anhydrase inhibitors were licensed for use only when beta-blockers were not tolerated or were contraindicated. The prescriber should follow relevant professional guidance, taking full responsibility for the decision. Informed consent should be obtained and documented. See the General Medical Council's Prescribing guidance: prescribing unlicensed medicines for further information.

[5] At the time of publication (November 2017), MMC did not have a UK marketing authorisation for this indication. The prescriber should follow relevant professional guidance, taking full responsibility for the decision. Informed consent should be obtained and documented. See the General Medical Council's Prescribing guidance: prescribing unlicensed medicines for further information.

  • National Institute for Health and Care Excellence (NICE)