Glaucoma: diagnosis and management

This guideline covers diagnosing and managing glaucoma in people aged 18 and over. It includes recommendations on testing and referral (case-finding) for chronic open-angle glaucoma and ocular hypertension and on effective diagnosis, treatment and reassessment to stop these conditions progressing.

# Recommendations
People have the right to be involved in discussions and make informed decisions about their care, as described in NICE's information on making decisions about 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.

# 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.
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)
-ptic 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 Goldmanntype 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. 
Do not base a decision to refer solely on IOP measurement using non-contact tonometry. 
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. 
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. 
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 Goldmanntype applanation tonometry. 
Provide results of all examinations and tests with the referral. 
Advise people with IOP below 24 mmHg to continue regular visits to their primary eye care professional. 
The following recommendations are for people planning and providing eye care services before referral.
People planning and providing eye care services should use a service model that includes Goldmanntype applanation tonometry before referral for diagnosis of COAG and related conditions. 
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. 

# Diagnosis
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
-ptic 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. 
Adopt professional or Department of Health and Social Care guidance to reduce the risk of transmitting infective agents via contact tonometry or gonioscopy.See the Royal College of Ophthalmologists' ophthalmic services guidance and the Department of Health and Social Care's guidance on minimising transmission risk of CJD and vCJD in healthcare settings. 
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). 
Obtain an optic nerve head image at diagnosis for baseline documentation (for example, a stereoscopic optic nerve head image or OCT). 
After referral, consider an early assessment appointment if there is clinical concern based on the information provided. 
At the time of diagnosis of ocular hypertension (OHT), assess the risk of future visual impairment, taking into account risk factors such as:
level of IOP
CCT
family history
life expectancy. 

# Standard practice for all assessments
Ensure that all of the following are 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 that could affect medicine choice
current systemic and topical medication
glaucoma medication record
drug allergies and intolerances. 
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). 
Ensure that all machines and measurement instruments are calibrated regularly according to the manufacturers' instructions. 

# Treatment
Take into account any cognitive and physical impairments when making decisions about management and treatment. 
Check that there are no relevant comorbidities or potential drug interactions before offering pharmacological treatment. 

## Treatment for people with OHT
Do not offer treatment to people with OHT who are not at risk of visual impairment within their lifetime. Advise people to continue regular visits to their primary eye care professional, at clinically appropriate intervals. 
Offer 360 selective laser trabeculoplasty (SLT) to people with newly diagnosed OHT with IOP of 24 mmHg or more (excluding cases associated with pigment dispersion syndrome) if they are at risk of visual impairment within their lifetime (see the recommendation on taking account of risk factors in the section on diagnosis). To help inform their decision, tell people:
that having 360 SLT can delay the need for eye drops and can reduce but does not remove the chance they will be needed at all
how long it may take for their IOP to improve after the procedure
about 360 SLTspecific side effects and complications and how long they are likely to last
that a second 360 SLT procedure may be needed at a later date. 
Consider a second 360 SLT for people with OHT if the effect of an initial successful SLT has subsequently reduced over time. 
For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on selective laser trabeculoplasty for people with ocular hypertension or chronic open angle glaucoma .
Full details of the evidence and the committee's discussion are in evidence review A: selective laser trabeculoplasty in ocular hypertension or chronic open-angle glaucoma adult patients.
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Offer a generic prostaglandin analogue (PGA) to people with OHT with IOP of 24 mmHg or more if they are at risk of visual impairment within their lifetime (see the recommendation on taking account of risk factors in the section on diagnosis) and:
they choose not to have 360 SLT or
 SLT is not suitable (for example, because they have pigment dispersion syndrome) or
they are waiting for 360 SLT and need an interim treatment or
they have had 360 SLT but need additional treatment to reduce their IOP sufficiently to prevent the risk of visual impairment.Demonstrate correct eye drop installation technique and observe the person using the correct technique when eye drops are first prescribed. 
See the recommendations on when to reassess for advice on when the next appointment should take place to assess the impact of any new treatments started.
For a short explanation of why the committee made this recommendation and how it might affect practice, see the rationale and impact section on generic PGAs for people with OHT or COAG .
Full details of the evidence and the committee's discussion are in evidence review A: selective laser trabeculoplasty in ocular hypertension or chronic open-angle glaucoma adult patients.
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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, and if this is not tolerated, offer a betablocker. If neither of these options is tolerated, offer a non-generic PGA, carbonic anhydrase inhibitor, sympathomimetic, miotic or a combination of treatments. 
Offer a medicine from another therapeutic class (beta-blocker, carbonic anhydrase inhibitor 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 medicines from different therapeutic classes may be needed at the same time to control IOP. 
Refer people to a consultant ophthalmologist to discuss other options if their IOP cannot be reduced sufficiently with 360 SLT or pharmacological treatment or both to prevent the risk of progression to sight loss. 
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. 

## Treatment for people with suspected COAG
Do not offer treatment to people with suspected COAG and IOP less than 24 mmHg unless they are at risk of visual impairment within their lifetime. Advise people to continue regular visits to their primary eye care professional, at clinically appropriate intervals. 

## Stopping treatment for people with OHT or suspected COAG
Discuss the benefits and risks of stopping treatment with people with OHT or suspected COAG who have both:
a low risk of developing visual impairment within their lifetime and
an acceptable IOP. If a person decides to stop treatment after this discussion, offer to assess their IOP in 1 month to 4 months with further reassessment if clinically indicated. 

## Treatment for people with COAG
In January 2022 the use of mitomycin-C (MMC) in recommendations 1.4.13 and 1.4.20 to 1.4.22 was off label. See NICE's information on prescribing medicines.
Offer people with advanced COAG, glaucoma surgery with pharmacological augmentation (MMC) as indicated. Give them information on the risks and benefits of surgery. 
Offer people who present with advanced COAG and who are listed for glaucoma surgery, interim treatment with a generic PGA. 
For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on selective laser trabeculoplasty for people with ocular hypertension or chronic open angle glaucoma .
Full details of the evidence and the committee's discussion are in evidence review A: selective laser trabeculoplasty in ocular hypertension or chronic open-angle glaucoma adult patients.
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Offer 360 SLT to people with newly diagnosed COAG (excluding cases associated with pigment dispersion syndrome). For people with advanced COAG see the section on treatment for people with advanced COAG and recommendation 1.4.24. To help inform their decision, tell people:
that having 360 SLT can delay the need for eye drops and can reduce but does not remove the chance they will be needed at all
how long it may take for their IOP to improve after the procedure
about 360 SLTspecific side effects and complications and how long they are likely to last
that a second 360 SLT procedure may be needed at a later date. 
Consider a second 360 SLT for people with COAG if the effect of an initial successful SLT has subsequently reduced over time. 
For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on selective laser trabeculoplasty for people with ocular hypertension or chronic open angle glaucoma .
Full details of the evidence and the committee's discussion are in evidence review A: selective laser trabeculoplasty in ocular hypertension or chronic open-angle glaucoma adult patients.
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Offer a generic PGA to people with COAG if:
they choose not to have 360 SLT or
 SLT is not suitable (for example because they have pigment dispersion syndrome) or
they are waiting for an 360 SLT and need an interim treatment or
they have previously had 360 SLT but need additional treatment to reduce their IOP sufficiently to prevent the risk of visual impairment.Demonstrate correct eye drop installation technique and observe the patient using the technique when eye drops are first prescribed. 
See recommendations on when to reassess for advice on when the next appointment should take place to assess the impact of any new treatments started.
For a short explanation of why the committee made this recommendation and how it might affect practice, see the rationale and impact section on generic PGAs for people with OHT or COAG .
Full details of the evidence and the committee's discussion are in evidence review A: selective laser trabeculoplasty in ocular hypertension or chronic open-angle glaucoma adult patients.
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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 medicine. 
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 with a generic PGA. 
Offer 1 of the following to people with satisfactory adherence to treatment and eye drop instillation technique whose IOP has not been reduced sufficiently to prevent the risk of progression to sight loss:
a medicine from another therapeutic class (a beta-blocker, carbonic anhydrase inhibitor or sympathomimetic); topical medicines from different therapeutic classes may be needed at the same time to control IOP or
 SLT or
glaucoma surgery with pharmacological augmentation (MMC) as indicated. 
Consider 360 SLT or glaucoma surgery with pharmacological augmentation (MMC) as indicated for people with COAG who are at risk of progressing to sight loss despite treatment with medicines from 2 therapeutic classes. Give them information on the risks and benefits of surgery. 
Consider 1 of the following for people with COAG who cannot tolerate a pharmacological treatment:
a medicine from another therapeutic class (a beta-blocker, carbonic anhydrase inhibitor 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 treatment with medicines from 2 therapeutic classes, consider 360 SLT or glaucoma surgery with pharmacological augmentation (MMC) as indicated. 
Offer 1 of the following to people with COAG whose IOP has not been reduced sufficiently to prevent the risk of progression to sight loss after glaucoma surgery:
pharmacological treatment; topical medicines from different therapeutic classes may be needed at the same time to control IOP or
further glaucoma surgery or
 SLT or
cyclodiode laser treatment. 
Offer 1 of the following to people with COAG (including advanced COAG) who prefer not to have glaucoma surgery or for whom glaucoma surgery is not suitable:
pharmacological treatment; topical medicines from different therapeutic classes may be needed at the same time to control IOP or
 SLT (for example in people with systemic comorbidities) or
cyclodiode laser treatment. 

# Reassessment

## Reassessment tests
At each assessment, offer the following tests to people with COAG, people with suspected 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. 
When clinically indicated, repeat gonioscopy, for example, if a previous examination has been inconclusive or there is suspicion of a change in clinical status of the anterior chamber angle. 
When clinically indicated, repeat visual field testing using standard automated perimetry (central thresholding test) for people with COAG and those with suspected visual field defects who are being investigated for possible COAG (see table 2 and table 3 for recommended reassessment intervals). 
When clinically indicated, repeat visual field testing using either a central thresholding test or a supra-threshold test for people with OHT and those with suspected COAG whose visual fields have previously been documented by standard threshold automated perimetry (central thresholding test) as being normal (see table 1 and table 2 for recommended reassessment intervals). 
When a visual field defect has previously been detected, use the same measurement strategy for each visual field assessment. 
When clinically indicated, repeat assessment of the optic nerve head (for example, stereoscopic slit lamp biomicroscopy or imaging). 
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. 
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. 

## When to reassess
At each assessment, re-evaluate the risk of conversion to COAG and the risk of sight loss to set time to next assessment. 
At each assessment, ask about general health and, if appropriate, factors affecting adherence to treatment, including cognitive impairment and any treatment side effects. 
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 the risk of conversion to COAG, and
reassess according to table 1. 
Conversion from ocular hypertension to chronic open angle glaucoma
Control of intraocular pressure
Time to next assessment
Not detected or uncertain conversion
No
Review management plan and reassess between 1 month and 4 months
Uncertain conversion
Yes
Reassess between 6 months and 12 months
No conversion detected
Yes
Reassess between 18 months and 24 months
Conversion
No or yes
See recommendations on diagnosis and reassessment of chronic open angle glaucoma
Use clinical judgement to decide when the next appointment should take place within the recommended interval, including the need to assess the impact of any new treatments started.
Uncertain conversion includes having insufficient accurate information (perhaps because the person was unable to participate in the assessment).
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. 
Conversion to chronic open angle glaucoma
Control of intraocular pressure
Time to next assessment
Not detected or uncertain conversion
No
Review management plan and reassess between 1 month and 4 months
Uncertain conversion
Yes
Reassess between 6 months and 12 months
No conversion detected
Yes
Reassess between 12 months and 18 months
Conversion
No or yes
See recommendations on diagnosis and reassessment of chronic open angle glaucoma
Use clinical judgement to decide when the next appointment should take place within the recommended interval, including the need to assess the impact of any new treatments started.
Uncertain conversion includes having insufficient accurate information (perhaps because the person was unable to participate in the assessment).
For people with COAG:
use clinical judgement to assess risk of COAG progression to sight loss, and
reassess according to table 3. 
Progression of chronic open angle glaucoma
Control of intraocular pressure
Time to next assessment
Not detected
No
Review treatment plan and reassess between 1 month and 4 months
Uncertain progression or progression
No
Review treatment plan and reassess between 1 month and 2 months
No progression detected and low clinical risk
Yes
Reassess between 12 months and 18 months
No progression detected and high clinical risk
Yes
Reassess between 6 months and 12 months
Uncertain progression or progression
Yes
Review treatment plan and reassess between 2 months and 6 months
Use clinical judgement to decide when the next appointment should take place within the recommended interval, including the need to assess the impact of any new treatments started.
Uncertain conversion includes having insufficient accurate information (perhaps because the person was unable to participate in the assessment).

## Discharge back to primary care
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. 
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. 

# Organisation of care
Refer people to a consultant ophthalmologist for consideration of a definitive diagnosis and formulation of a management plan if:
they have suspected optic nerve damage or repeatable visual field defect, or both, or
SLT treatment is suitable (see recommendation 1.4.4 and recommendation 1.4.15 for people with newly diagnosed OHT and COAG). 
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. 
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. 
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 slit lamp binocular indirect ophthalmoscopy
gonioscopy
van Herick peripheral anterior chamber depth assessment
CCT measurement. 
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. 
Healthcare professionals involved in monitoring and treating OHT, suspected COAG and established COAG should be trained to make management decisions on:
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 and stereoscopic slit lamp biomicroscopic examination of anterior segment and posterior segment)
pharmacology of IOPlowering medicines
eligibility for 360 SLT
treatment changes for COAG, suspected COAG and OHT (with consideration given to relevant contraindications and interactions). 
Healthcare professionals should discuss with the responsible consultant ophthalmologist the decision to offer 360 SLT and how it will be performed. Healthcare professionals undertaking 360 SLT should be given support by the responsible consultant ophthalmologist. Training should include:
the suitability of the procedure
laser safety and procedures
benefits and risks of 360 SLT, and how to discuss these with patients and their family members or carers (as appropriate)
patient consent. 
For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on organisation of care .
Full details of the evidence and the committee's discussion are in evidence review A: selective laser trabeculoplasty in ocular hypertension or chronic open-angle glaucoma adult patients.
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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 the 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. 
Healthcare professionals who diagnose, treat or monitor independently of consultant ophthalmologist supervision should take full responsibility for the care they provide. 

# Providing information
Ensure that people are offered the opportunity to discuss their diagnosis, referral, prognosis, treatment and discharge so they can take an active part in decision making (see NICE's guideline on shared decision making). Provide them with relevant information in an accessible format at initial and subsequent visits. This should include telling them:
about 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
the different types of treatment options, including mode of action, frequency and severity of side effects, and risks and benefits of treatment
that glaucoma can run in families and that family members may wish to be tested for the condition
the importance of their role in their own treatment  for example, the ongoing regular application of eye drops to preserve sight. 
Ensure that people are given practical information and advice on:
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)
how to contact the eye clinic liaison officer (ECLO) and what information and assistance they can provide
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. 

# 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.

## MMC
MitomycinC is an antimetabolite used during the initial stages of trabeculectomy to prevent excessive postoperative scarring and therefore reduce the risk of failure.

## 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 2tier 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 unaware 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 must 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 that cannot be corrected with standard glasses or contact lenses and reduces a person's ability to function in a visual environment.# Recommendations for research
The guideline committee has made the following recommendations for research.

# Key recommendations for research

## Risk tools to identify risk of developing chronic open angle glaucoma and risk of sight loss
What is the predictive value of risk tools for identifying people in the community who are at increased risk of developing chronic open angle glaucoma (COAG) and identifying people with COAG who are at increased risk of sight loss?

## Long-term effectiveness of selective laser trabeculoplasty
What is the long-term effectiveness and cost effectiveness of selective laser trabeculoplasty as a first-line treatment compared with intraocular pressure-lowering eye drops in ocular hypertension or COAG in adults?

## An instrument to measure quality of life in people with glaucoma
What instrument should be used to measure health-related quality of life in people with glaucoma?

## Optical coherence tomography for glaucoma
What is the effectiveness and cost effectiveness of optical coherence tomography for diagnosing and monitoring glaucoma?

## Referral filtering
What is the effectiveness and cost effectiveness of the different models for glaucoma filtering (pathways from case-finding to assessment in secondary ophthalmic care) for detecting glaucoma and glaucoma-related conditions (ocular hypertension and suspected glaucoma)?

# Other recommendations for research

## Treatment for people with an intraocular pressure of 22 mmHg or 23 mmHg
What is the clinical and cost effectiveness of treating an intraocular pressure of 22 mmHg or 23 mmHg in people with normal optic discs and visual fields?
For a short explanation of why the committee made the recommendation for research, see the rationale section on selective laser trabeculoplasty for people with ocular hypertension and chronic open angle glaucoma .
Full details of the evidence and the committee's discussion are in evidence review A: selective laser trabeculoplasty in ocular hypertension or chronic open-angle glaucoma adult patients.
Loading. Please wait.# Rationale and impact
These sections briefly explain why the committee made the recommendations and how they might affect practice.

# Selective laser trabeculoplasty for people with ocular hypertension or chronic open angle glaucoma
Recommendations 1.4.4 and 1.4.5 and recommendations 1.4.15 and 1.4.16

## Why the committee made the recommendations
The committee agreed that the key outcome for adults with ocular hypertension (OHT) or chronic open angle glaucoma (COAG) was visual field progression that, in the long-term, could affect people's vision. Intraocular pressure (IOP) was considered to be a relevant surrogate outcome because lowering IOP can prevent the risk of optic nerve damage and sight loss. High-quality evidence showed that there is no meaningful difference between 360 selective laser trabeculoplasty (SLT) and eye drops in achieving a target IOP, health-related quality of life, risk of total adverse events, and treatment adherence. The evidence did show that that there were transient adverse events associated with SLT such as transient discomfort, blurred vision, photophobia and hyperaemia. It was also highlighted that there are rare complications associated with SLT. While rare events were not highlighted in the evidence, corneal failure is possible after SLT procedures. In people who have first-line treatment with eye drops compared with first-line 360 SLT, more people used eye drops and more people have more than 1 eye drop medication at 12 months.
The cost-effectiveness evidence showed that first-line treatment with 360 SLT was more effective and less costly compared with eye drops, with at least 90% probability of being the more cost-effective option. For costs, this result was driven by treatment involving 360 SLT costing less overall compared with eye drops alone. This is because the additional upfront costs of 360 SLT were outweighed by the accumulating costs of eye drops over time. For quality of life, 360 SLT resulted in a longer period without eye drops, or with fewer eye drops, and slightly slower estimated progression rates for glaucoma. Although no statistically significant direct benefit on quality of life was found in the trial, additional data on the natural history of glaucoma, which was incorporated into the cost-effectiveness analysis, suggests that quality of life was likely to be improved. The cost-effectiveness analysis included the costs and benefits of a second 360 SLT if the clinicians deemed it necessary. Even if 360 SLT was assumed to have the same clinical effectiveness as eye drops, it would still be a highly cost-effective treatment, because of the estimated reduction in overall costs.
Based on this evidence and their clinical experience, the committee recommended 360 SLT as first-line treatment for people with newly diagnosed OHT or newly diagnosed COAG. The recommendation excludes cases associated with pigment dispersion syndrome. This was because there was no evidence on the use of 360 SLT in people with pigment dispersion syndrome and the committee agreed that eye drop treatment is more suitable for those people. The recommendation lists information to give to people to help them make a decision on having SLT as first-line treatment, including telling them about 360 SLTspecific side effects and complications and how long they are likely to last.
The committee noted that SLT may need to be repeated. This was included in the cost-effectiveness analyses (with approximately 15% of people in the SLT arm having a second procedure within the first year), which gave the committee more confidence in the result, as it reflected their expectations of how the treatment would be used in practice. The committee recommended that a second 360 SLT could be needed if the effect of an initial successful 360 SLT has subsequently reduced over time. This means that the IOP level has gone up and clinicians need to decide if there is risk of progression of COAG or conversion of OHT to COAG. The second 360 SLT should be given at the discretion of the responsible consultant ophthalmologist. This follows the procedure used in the main UK randomised trial (the LiGHT trial).
The committee further highlighted that in general, treatment to reduce IOP has to work for at least 6 months to be considered successful. However, this can also be based on clinician discretion.
The committee highlighted that there was a lack of long-term evidence on progression of glaucomatous visual field defect and progression of optic nerve head damage. The committee also highlighted that patients care more about vision outcomes than other outcomes such as IOP. A research recommendation was developed to cover this gap in the evidence on the long-term effectiveness of 360 SLT (with follow-up times of 3 years or more, 5 years and 10 years).

## Impact on other recommendations
The committee considered the impact of recommending 360 SLT on other recommendations in the guideline. Recommendations were amended as necessary, taking into account the original evidence for each recommendation and the committee's knowledge and experience.

## How the recommendations might affect practice
The recommendations are likely to result in a significant change in practice, because more people with newly diagnosed OHT or COAG could be offered 360 SLT as their first treatment. The committee also noted that larger centres may see more referrals, resulting in an increase in the number of clinics per week. The committee highlighted that, although the increase should not be significant, any increase means there will be a change to the organisation of care. Overall, this is not likely to have a substantial cost impact because evidence shows that first-line 360 SLT (including the purchase and maintenance of the SLT machine) was less costly than first-line use of eye drops. However, there will be changes in the types of costs incurred, with significant reductions in the cost of eye drop prescriptions but increases in costs for SLT devices and staffing.
Return to recommendations 1.4.4 and 1.4.5
Return to recommendations 1.4.15 and 1.4.16

# Generic PGAs for people with OHT or COAG
Recommendation 1.4.6 and recommendation 1.4.17

## Why the committee made the recommendations
The 2017 guideline recommended prostaglandin analogue (PGA) eye drops for OHT or COAG. The committee amended this to reflect the new 2022 recommendations on using 360 SLT. They agreed that people who prefer not to have 360 SLT or for whom it is not suitable should be offered generic PGA eye drops. This was because PGA eye drops were used for first-line treatment in the 2017 guideline and in the LiGHT trial.
The recommendations were also amended to highlight that eye drop installation technique should be demonstrated and that healthcare professionals should observe the person to confirm that their installation technique is correct. It is recommended that this be done when eye drops are first prescribed.
Return to recommendation 1.4.6
Return to recommendation 1.4.17

# Organisation of care
Recommendations 1.6.6 and 1.6.7

## Why the committee made the recommendations
The committee noted that the first-line use of 360 SLT to treat OHT or COAG might lead to a significant change in practice that requires different organisation of care and the establishment of a multidisciplinary team. The committee wanted to make clear that if 360 SLT is suitable for a person, that person should be referred to a consultant ophthalmologist. They also discussed the safety of the 360 SLT procedure and agreed that healthcare professionals should discuss with the responsible consultant ophthalmologist the decision to offer it and how it will be performed. This means that with support from a consultant ophthalmologist, healthcare professionals such as specialty doctors, associate specialists, specialist nurses, optometrists and allied health professionals can perform 360 SLT.
The committee also noted that healthcare professionals who provide 360 SLT should be given support and have relevant training on the suitability and safety of the procedure, including its benefits and risks. They should also be trained in discussing these points and patient consent with patients and their family members or carers. A similar approach was taken in the LiGHT trial, in which training was given to all treating surgeons before recruitment, and the chief investigator, who was a consultant ophthalmic surgeon, observed each surgeon perform at least 1 laser treatment. Based on these discussions, new recommendations were added to provide further clarification on organisation of care.

## How the recommendations might affect practice
The recommendations are likely to result in a significant change in practice because training and support will be needed for healthcare professionals performing the 360 SLT procedure.
Return to recommendations 1.6.6 and 1.6.7# Context
The scope of this NICE guideline on diagnosis and management of glaucoma was extended to cover referral in 2017. This included the most effective service models for referral filtering schemes (repeat measures, enhanced case-finding and referral refinement), the tests to be used for finding people with chronic open angle glaucoma (COAG), suspected COAG and ocular hypertension (OHT), and thresholds for onward referral. In 2017, the guidance was also updated on tests for diagnosis and reassessment, pharmacological treatments for lowering intraocular pressure (IOP) and preserving visual field, and reassessment intervals, which depend on prognosis.
The 2017 update provided an opportunity to re-evaluate the clinical effectiveness, cost effectiveness and indications for treating OHT. Knowledge of corneal thickness is no longer needed to decide whether to treat OHT and a single threshold of 24 mmHg is now recommended for both onward referral and treatment. Changes in the costs of pharmacological treatments, acknowledgement of short- and long-term variations in IOP and the uneven relationship between rising pressure and increased risk have allowed a simplification of the indications for OHT treatment.
Control of IOP remains critical to the therapeutic approach. Intensity of treatment and ongoing management are guided by disease severity and progression as shown by visual field change, morphological change in the optic disc, and the likelihood of progressive sight loss. Reassessment at each visit is emphasised, encouraging flexible clinical judgement about the frequency of visits and options for treatment, including stopping treatment when the perceived lifetime risk of developing visual impairment is low.
Since the update in 2017, there has been new evidence on the use of 360 selective laser trabeculoplasty as a first-line treatment for OHT and COAG. Therefore, recommendations on treatment for people with OHT or COAG were updated.
Sections of the guideline on accuracy of visual field tests, surgical interventions, and information, education and support needed for adherence to treatment have not been updated because no new evidence was found.