Mr John Sparrow discusses the recommendations from the NICE guideline on the diagnosis and management of chronic open-angle glaucoma and ocular hypertension

NICE published its guideline on glaucoma and ocular hypertension in April 2009.1 Glaucoma is a common, serious, and potentially blinding eye condition that affects around 2% of people over 40 years of age,2,3 and ocular hypertension (OHT) affects another 3%–5% of individuals in that age group.4 Prevalence is strongly age dependent, and is higher in people of African descent and in those with a positive family history.1

In England, the eye service in hospitals currently delivers ~5.2 million or just under 10% of all NHS outpatient department visits.5 Of these, an estimated 25%–40% are related to glaucoma, and so annually there are 1–2 million glaucoma patient visits to the eye service in English hospitals. Around 10% of blindness and partial-sight certifications record glaucoma as the main cause of sight loss.6 In recent years, our ability to provide services for chronic diseases that require lifelong treatment and monitoring has been restricted by new patient-access targets, waiting-time targets for surgery, and fresh demands on the existing capacity of the hospital eye service for the urgent delivery of new treatments for eye diseases that cause blindness. For a condition such as glaucoma, this has led to variable standards of care with cancellations and long delays for follow-up visits that result in anxiety for many and harm for a minority of patients.7 This reappraisal of the effectiveness and cost-effectiveness of glaucoma treatment is needed to reposition glaucoma care in terms of its legitimate priority for the utilisation of NHS resources. As with all NICE guidelines, exceptions will arise and the intention is that the guideline should apply to 80% of clinical situations on 80% of occasions.4

The guideline covers people who develop chronic open-angle glaucoma (COAG) and OHT as adults, and specifically excludes congenital and infantile glaucoma. Also excluded is screening, which has recently been the subject of an NHS R&D Health Technology Assessment Programme report.3


Chronic open-angle glaucoma is the commonest form of glaucoma in white European and black African or black Caribbean populations. It is characterised by damage to the optic nerve with excavation of the optic nerve head (cupping), characteristic visual field loss, and elevated intraocular pressure (IOP) in a majority of those affected. Chronic open-angle glaucoma associated with elevated IOP is frequently termed primary open-angle glaucoma; when IOP is not elevated the terms normal- or low-tension glaucoma may be used.

Ocular hypertension is used to describe cases with elevated IOP and normal optic discs and visual fields. When the latter two findings are equivocal, the term ‘COAG suspect’ may be used. ‘Suspects’ may or may not have elevated IOP, so, for example, a person may be a normal-tension glaucoma suspect.4


Specialist procedures and equipment are required to establish a diagnosis. The NICE guideline recommends IOP measurement using Goldmann applanation tonometry (slit-lamp mounted), disc and fundus examination using stereoscopic slit-lamp biomicroscopy, peripheral anterior chamber configuration and depth assessments using gonioscopy, and central corneal thickness (CCT) measurement.1,4 A diagnosis of COAG and the establishment of a management plan should be undertaken by a consultant ophthalmologist or someone working under their supervision. A diagnosis of OHT may be made independently by a healthcare provider with a specialist qualification and relevant experience (e.g. a suitably qualified optometrist or nurse).1,4

Treatment for chronic open-angle glaucoma

The purpose of treatment is to maintain a sighted lifetime. For untreated COAG, the mean time to blindness in at least one eye has been estimated as 23 years compared to 35 years with treatment.3 The only treatment known to slow the progression of COAG effectively is to lower the IOP.4 Knowledge of the untreated IOP allows a ‘target pressure’ to be set, a dynamic concept of what the IOP should be to minimise or arrest future disease progression.4 For the majority of patients with mild-to-moderate glaucoma damage, pharmacological agents applied topically as eye drops are the only treatments needed. A prostaglandin analogue is recommended by NICE as the initial first-choice treatment; other commonly used topical agents include beta blockers, carbonic anhydrase inhibitors, and sympathomimetics.1,4 If IOP cannot be lowered sufficiently by topical agents (through lack of efficacy or intolerance) or if disease progression continues despite seemingly adequate pressure control, glaucoma-drainage surgery (trabeculectomy) should be offered to lower the IOP further.4 Patients who first present with advanced glaucoma damage should be offered surgery, since this is the most effective method of IOP control.4

Treatment for ocular hypertension

Treatment for certain patients with OHT who are at higher risk of progression is both effective and cost effective in preventing blindness in the long term.1 Risk strata for treatment eligibility are detailed in the guideline and depend on age (a proxy for future life expectancy), level of untreated IOP, and CCT.1,4 Patients with OHT may or may not have other features suggestive of possible glaucoma, and conversely some COAG suspects will have OHT and others will not. The treatment indications are based on the presence of OHT,1 and COAG suspects without OHT should not be treated. All these groups of individuals, however, should be monitored in accordance with their level of perceived risk: if a patient converts to definite COAG then management should change accordingly.1,4


Regular risk-based monitoring forms an essential component of care.4 Intraocular pressure control may slip unpredictably and, even with seemingly adequate control, there may be progression of optic disc and visual field damage. The assessments needed at monitoring visits are detailed in the guideline, and checking adherence to treatment and possible side-effects should form part of the routine.1,4 Monitoring intervals (ranges) are specified in the guideline for both COAG and OHT.1,4 Monitoring for COAG should be done either by or under the supervision of a consultant ophthalmologist, or by healthcare providers with advanced levels of training, specialist qualifications, and experience. Requirements for monitoring OHT and those suspected of possible COAG are less stringent and may, for example, be undertaken by optometrists with entry-level competency, provided a suitably qualified person has established a diagnosis and management plan.

Organisation of care

The underpinning principle for organisation of care is that the right care should be provided to the right patient by the right care provider. Those whose clinical risk is greatest should be cared for by the most-skilled specialists, while those at a lesser clinical risk may be cared for by individuals with lower levels of training, knowledge, and skill. Typically, patients at higher risk of progression remain under the supervising care of consultant ophthalmologists, while those at lower risk, for example those with OHT, can be cared for in the community in outreach settings or in participating high-street optometric practices. The guideline details various levels of skill (knowledge, qualifications, and experience) needed to care for different case-mix complexities.1,4

Provision of information

Patients with a better understanding of their condition tend to be more adherent to treatment requirements and may, as a result, have better outcomes.1 Provision of context-relevant information to patients that is appropriate for their condition, level of interest, and need, is important and it is recommended that a range of information sources be made available as necessary. A version of the guideline, Understanding NICE guidance,8 has been written specifically for patients and the public to help them understand the monitoring and care they should expect to receive.

Challenges for implementation

As general practitioners are usually not involved directly in the delivery of glaucoma care most of the challenges around implementation are dealt with by other healthcare providers. The new treatment indication for patients with OHT at higher risk of progression now means that affected individuals need to be identified and risk-assessed for possible eligibility for treatment. Identification of people with OHT should be done in accordance with the standard IOP measurement method, that is by Goldmann applanation tonometry (slit-lamp mounted).1,4 Optometrists who work in primary eye care are all required to be competent in this technique, although there is reluctance to use it as it needs a higher level of skill than required for air-puff tonometry, which can be delegated to a technician. Unfortunately, on the day of publication of the guideline, the body that provides optometrists with their professional insurance advised that they must immediately refer all patients with elevated IOP measurements, regardless of the instrument used to make these measurements.9 This advice ignores the recommended instrumentation as well as the 3-year implementation period proposed by NICE1 and has resulted in a flood of false-positive referrals. Primary care trusts are generally aware of the issue and many are setting up IOP triage clinics to deal with this problem.


Through a combination of intervention and prevention, the NICE guideline recommendations will improve the chances of a sighted lifetime for people with COAG, OHT, and those suspected of possible COAG in the medium and long term. Evidence-based treatments and timely monitoring should focus on the needs of affected individuals, with an emphasis on integrated care pathways unimpeded by organisational boundaries.

Note about the article

This article presents the personal views of the author, who chaired the Guideline Development Group (GDG), and does not necessarily represent those of NICE or the other members of the GDG.

NICE implementation tools

NICE has developed the following tools to support implementation of its guideline on Glaucoma: diagnosis and management of chronic open angle glaucoma and ocular hypertension. They are now available to download from the NICE website:

Costing tools
National cost reports and local cost templates for the guideline have been produced:

  • costing reports are estimates of the national cost impact arising from implementation based on assumptions about current practice, and predictions of how it might change following implementation of the guideline
  • costing templates are spreadsheets that allow individual NHS organisations and local health economies to estimate the costs of implementation taking into account local variation from the national estimates, and they quickly assess the impact the guideline may have on local budgets.


Slide set
The slides are aimed at supporting organisations to raise awareness of the guideline and resulting implementation issues at a local level, and can be edited to cater for local audiences. This information does not supersede or replace the guidance itself.

Audit support
Audit support has been developed to support the implementation of the NICE guideline on glaucoma. The aim is to help NHS organisations with a baseline assessment and to assist with the audit process, thereby helping to ensure that practice is in line with the NICE recommendations. The audit support is based on the key recommendations of the guidance and includes criteria and data collection tools.

  • The NICE guideline and the advice from the optometrist’s professional insurance body to refer all patients with raised intraocular pressures have already caused a surge in ophthalmology referrals
  • This is unnecessary and PBC consortia should ensure that they have a community specialist optometry service to address this issue immediately
  • This service could just triage referrals or carry out the recommended specialist assessment to define whether a consultant ophthalmologist opinion is needed
  • OHT and suspected COAG can be treated and monitored in community optometrist-led clinics but under specialist supervision and thus at less than full tariff price
  • Ideally local PBC leads, PCT commissioners, community optometrists, and ophthalmology consultants should agree a local care pathway to ensure patients with OHT or COAG receive their care in the most effective and cost efficient manner
  • Tariff price: ophthalmology outpatient = £110 (new), £53 (follow up)a
  1. National Institute for Health and Care Excellence. Glaucoma: diagnosis and management of chronic open angle glaucoma and ocular hypertension. Clinical Guideline 85. London: NICE, 2009. Available at:
  2. Rudnicka A, Mt-Isa S, Owen C et al. Variations in primary open-angle glaucoma prevalence by age, gender, and race: a Bayesian meta-analysis. Invest Ophthalmol Vis Sci 2006; 47 (10): 4254–4261.
  3. Burr J, Mowatt G, Hernandez R et al. The clinical effectiveness and cost-effectiveness of screening for open angle glaucoma: a systematic review and economic evaluation. Health Technol Assess 2007; 11 (41): iii–iv, ix–x, 1–190.
  4. National Collaborating Centre for Acute Care. Glaucoma: diagnosis and management of chronic open angle glaucoma and ocular hypertension. London: NCCAC, 2009. Available at:
  5. HESonline. Outpatient data—main specialty 2007–2008. (accessed 28 August 2009).
  6. Bunce C, Wormald R. Leading causes of certification for blindness and partial sight in England & Wales. BMC Public Health 2006; 6 (58): 1–7. Available at:
  7. National Patient Safety Agency. Rapid response report: preventing delay to follow up for patients with glaucoma. NPSA, 2009. Available at:
  8. National Institute for Health and Care Excellence. Understanding NICE guidance: information for people who use NHS services. London: NICE, 2009. Available at:
  9. Association of British Dispensing Opticians, Association of Optometrists, Federation of Ophthalmic and Dispensing Opticians. Advice on NICE glaucoma guidelines. London: ABDO, AOP, FODO, 2009. Available at: G