The IGA can help you set up a patient support group in your area.
For more information, please contact:
Subhash Suthar– London, East Anglia and the South East
Tel. 07810 48 47 47
David Harris – the Midlands the North
Tel. 07854 82 19 11
John Hughes – Scotland
Tel. 07889 10 21 89
Eryl Williams – Wales and the South West
Tel. 07856 68 79 31
65% of patients stop taking their eye drops within 12 months. One major reason is the difficulty in instilling the drops.
(Reardon G et al. Am J Ophthalmol 2004; 137:S3–12. Z Zhou, R Althin, B S Sforzolini and R Dhawan, Br. J Ophthlmol. 2004; 88, 1391–1394.)
People are more likely to follow treatment regimes that they understand and that have been chosen with an appreciation of their individual needs and life circumstances.
(The Association of the British Pharmaceutical Industry (ABPI) 2004)
The Vision of the IGA is "To ensure that all people with or at risk of glaucoma have the knowledge and access to care that will enable them to maintain a good quality of life." On that basis, it is logical the IGA should become more deeply involved in the education of patients in an effort to improve adherence and their long-term quality of life.
The IGA is in a unique position to be able to address this issue as an independent charity, with no allegiance to any manufacturer of topical drops or compliance aids.
To that end, the IGA aims to supply every prime ophthalmic department in the UK with an educational tool to assist health care professionals counsel their patients on their disease and the importance of adherence to both appointments and therapy.
The tool takes the form of a briefcase containing:
This briefcase is delivered to the ophthalmic departments on request by IGA staff, who will train the health care professionals on how to use the tool effectively.
This allows the health care professionals the freedom to simply pick up and transport it easily to satellite units or domiciliary visits.
To find out more, contact:
Subhash Suthur, London, East Anglia and the South East, tel. 07810 48 47 47 or email: firstname.lastname@example.org; David Harris, the Midlands the North, tel. 07854 82 19 11 or email: email@example.com; or John Hughes, Scotland, tel. 07889 10 21 89 or email: firstname.lastname@example.org.
Each year, the IGA grants committee awards grants of various amounts with the objective to fund research into early diagnosis, pathology, treatments and epidemiology of glaucoma. Over the past 10 years, this has helped funding many projects amounting to a total of £2.5million.
Grants are distributed via the UK & Eire Glaucoma Society, the Royal College of Ophthalmologists and following direct applications made to the Chairman.
Glaucoma in 2004 and Beyond, report by Rod McNeil
The IGA's inaugural professional symposium reviewed current issues and developments in glaucoma care, including epidemiology, patient examination and treatment approaches.The IGA hosted its first professional scientific symposium on June 14 at the Institute of Physics in London.
Attended by over 40 healthcare professionals including nurse practitioners, optometrists and orthoptists, the symposium faculty reviewed developments in understanding the epidemiology of glaucoma, practice recommendations in visual field testing and measurement of intraocular pressure (IOP), and current trends in the medical and surgical treatment of glaucoma.
Understanding the epidemiology of open-angle glaucoma
Stephen Vernon, consultant ophthalmologist at Queen's Medical Centre, University Hospital Nottingham, opened the symposium with a review of research on glaucoma epidemiology, covering prevalence and incidence data as well as major risk factors for open-angle glaucoma.
He presented a modern view of progressive open angle glaucoma, described as an optic neuropathy characterised by a progressive loss of nerve fibres leading to optic disc excavation and visual field loss. Glaucoma is typically not detected until there is significant loss of retinal ganglion cells. Also, patterns of disease vary enormously in glaucoma, although it's linked in part to IOP.
Summary prevalence estimates of open-angle glaucoma (OAG) in the United States, based on a meta-analysis of recent population-based studies in the United States, Australia, and Europe, found an estimated overall prevalence of OAG in the US population 40 years and older of 1.86% (95% confidence interval, 1.75%-1.96%).1 An estimated 1.57 million white and 398,000 black persons were affected. Owing to the rapidly aging population, the number with OAG will increase by 50% to 3.36 million in 2020. Black subjects had almost 3 times the age-adjusted prevalence of glaucoma than white subjects.
All prevalence studies show an increase with age. Major risk factors for primary OAG include age, race, family history and intraocular pressure. Other risk factors, noted Mr Vernon, include hypertension, diabetes, migraine and Raynaud's, nocturnal hypotension and refractive error. The Baltimore Eye Study found an incidence of POAG of 7.1% in blacks and 3% in whites. It also found that risk rises with increasing IOP at baseline: risk was 7 times greater if the original IOP was greater than 30 mmHg (vs. IOP <21 mmHg).
Mr Vernon commented that prevalence studies help define the pattern of disease in the community, define the known cases to occult cases ratio, help in the selection of potential screening tests and define a baseline for future studies on incidence. However, such studies do not tell us about the natural history of disease subgroups or the outcome of future screening programmes.
Measurement of intraocular pressure
In another presentation on measurement of IOP, Mr Vernon emphasised that all 'measurements' are estimations of true IOP. Also, the intraocular pressure follows a circadian cycle, often with a maximum between 8 a.m. and 11 a.m. and a minimum between midnight and 2 a.m. The diurnal variation can be between 3 and 5 mmHg and is wider in untreated glaucoma.
Goldmann applanation tonometry remains the gold standard measurement, but care is required. Confounding variables include increased venous pressure, muscle contraction and eye position. For example, valsalvas can produce up to 80% increase in pressure and accommodation can reduce IOP by up to 4.5 mmHg. Non-contact tonometry can be reliable if used appropriately but pneumo-tonometry using the OBF is not reliable for IOP readings. Mr Vernon noted that it was essential to measure central corneal thickness in suspects and normal tension glaucoma cases. Thick corneas can give an artificially high pressure reading, while individuals with normal tension glaucoma tend to have thinner corneas than normal.
Glaucoma tests: visual fields
Michael Miller, consultant ophthalmologist at Moorfields Eye Hospital, presented a series of case illustrations to demonstrate common mistakes that occur when testing visual fields. He stressed the need to recognise the causes of artefactual defects (i.e., not true visual defects) when using automated perimetry, underscoring the inherent variability in patient responses. According to Mr Miller, if you are not producing quality data, it is not worth doing the test (table 1).
Potential causes of artefactual defects include incorrect fixation, slow starters, early finishers and overpressing. Poor field performers are another concern: some patients produce consistently poor results, despite best efforts. In such patients, manual perimetry may be a more helpful alternative to avoid incorrect diagnosis and inappropriate interventions. Mr Miller explained that gross lens rim artefact is a common cause of inappropriate referrals. This is due to the poor position of the lens in front of the patient, such that the lens rim obscures the patient's view of the perimeter. It will also occur if the patient's head drops back from the forehead rest during the test.
Ted Garway-Heath, consultant ophthalmologist at the Glaucoma Research Unit, Moorfields Eye Hospital, discussed the importance of assessing the optic nerve head and retinal nerve fibre layer. He explained that assessing the optic disc is at least as important as visual field testing and IOP measurement. The pupil should be dilated to allow stereoscopic examination of the optic nerve head (rather than direct ophthalmoscopy), with the use of a narrow slit beam of moderate light intensity. The examiner should draw the disc and nerve fibre layer, recording the illustration in the patient notes.
Glaucoma is characterised by progressive thinning of the neuroretinal rim. The pattern of loss of rim varies and may be marked by diffuse thinning, localised notching or both. Thinning of the rim, while occurring in all disc sectors, is generally greatest at the inferior and superior poles, leading to a loss of physiological rim shape so that the infero-temporal rim is no longer the thickest. The optic cup often enlarges in all directions, but usually becomes vertically oval. As well as assessing the contour of the neuororetinal rim, other factors to watch for include optic disc haemorrhages and parapapillary atrophy. It was noted that parapapillary atrophy is least frequent in normal eyes in the nasal disc sector.
Imaging, for example using optic disc photography or scanning laser polarimetry, is likely to play a role in the future for longitudinal follow-up. A good rule of thumb is to take at least two baseline images to improve the chance of detecting progression, said Mr Garway-Heath. Confirmed worsening of the optic nerve head or retinal nerve fibre layer parameters is a strong sign of glaucoma progression.
Mr Garway-Heath reviewed guideline recommendations for managing glaucoma, including indications for medical treatment and the importance of compliance with prescribed medication. The aim of treatment is to slow the rate of progression by modifying the risk factor intraocular pressure.
Target pressure was described as the range of pressure that the treating physician judges is sufficient to prevent functional visual impairment within the patient's lifetime. It is a moving target, he said. Under revised guidelines from the European Glaucoma Society (EGS), target pressure should be determined following determination of the amount of glaucoma damage, life expectancy and the initial IOP level at which damage started to occur.
Factors to consider when choosing glaucoma drops are efficacy, safety, topical tolerability, compliance, drug interactions and cost. All high-pressure glaucoma cases are due to problems with aqueous drainage, and all drugs approved to treat glaucoma are licensed as IOP lowering agents. Available mechanisms of action include reduction of aqueous production, for example with beta-blockers or carbonic anhydrase inhibitors, increased aqueous outflow through the trabecular meshwork, for example with cholinergic drugs, or increased uveoscleral outflow with prostaglandin-related ophthalmic drugs.
Mr Garway-Heath discussed the main features of the various classes of commonly used antiglaucoma agents (figure 1). The EGS recommend that the least amount of medication and side effects to achieve the therapeutic response should be a consistent goal. He noted that prostaglandin-related antiglaucoma medications are the most potent pressure lowering eye drops available, while beta blockers, the most frequently used agents until recently, may cause ill health and can, in rare cases, cause sudden death.
Factors influencing patient compliance with prescribed medication include memory, topical and systemic side effects of treatment, manual dexterity (some bottles are easier to use than others), the simplicity of the treatment regime and the degree of understanding of the disease (table 3). In the case of multiple drug regimes, fixed combination preparations should be chosen wherever possible. According to the EGS, when available, combined drug preparations are generally preferable to two separate instillations of the same agents, due to improved compliance and positive influence on dosing schedule and quality of life. The simpler the treatment regime, the greater the likelihood of good patient compliance.
Current surgical and laser treatments in glaucoma
Mr Peter S Phelan, consultant ophthalmologist at Sunderland Eye Hospital, outlined current surgical and laser treatments in glaucoma. It is first of all vitally important to decide whether any intervention is required, he advised. But having decided that additional or alternative intervention besides medical treatment is required or may be beneficial, treatment should be tailored according to patient and surgeon preferences.
Surgery may be considered where there is progression despite medical treatment, or there is a lack of compliance, a need for a lower IOP or coincidental cataract. The current operation of choice in primary open-angle glaucoma is trabeculectomy, which produces a 'guarded' fistula between the anterior chamber and the subconjunctival space. Long-term IOP control is achieved in many cases, although some patients do require further therapy or repeat surgery. It was noted that trabeculectomy does not cure glaucoma, does not improve vision and can make the eye red and sore. Also, it may cause cataract in years to come.
The possible benefits of combined cataract removal and trabeculectomy were highlighted, although there were decreasing numbers of phako trabeculectomies with the advent of newer antiglaucoma medications. Argon laser trabeculoplasty had its greatest popularity in the UK in the early 80s, but limited success and the possibility of compromised future drainage procedure has limited its popularity in the UK.
Glaucoma care in the future
The symposium closed with a lively debate on the implications of the latest recommendations from the Department of Health encouraging extended management of chronic eye diseases including glaucoma in community settings. A key recommendation from the National Eye Care Services Steering Group was that it is preferable for many individuals with glaucoma and most of those with suspect glaucoma to be managed within their own community, where this can be achieved equitably and effectively. It also concluded that [specially trained] optometrists and ophthalmic medical practitioners were best suited to independently manage glaucoma and its related conditions in the community.
1. Friedman DS, Wolfs RC, O'Colmain BJ et al; Eye Diseases Prevalence Research Group. Prevalence of open-angle glaucoma among adults in the United States.
Arch Ophthalmol. 2004;122:532-8.
Table 1: Practicalities on visual field examination*
Most patients become more proficient after their first examination. This effect shows as an improvement in the test and is called 'learning effect'. The first tests in a perimetrically naïve subject should be considered with caution or discarded.
To be clinically significant, a visual field defect must be real. To be real, it must be confirmed on repeated examinations.
Media opacity and miotic pupils worsen the mean deviation through a generalised depression of sensitivity.
Disc features must match the visual field defects.
Rule out other ocular causes of visual field defects, i.e., retinochoroidal lesions.
* The European Glaucoma Society. II Edition: Terminology and Guidelines for Glaucoma 2003.
Table 2: Main properties of commonly used antiglaucoma pressure-lowering agents
Parameter: Comparative properties
Efficacy: Prostaglandins > beta blockers/alpha2 agonists/cholinergic drugs > carbonic anhydrase inhibitors
Safety: Prostaglandins/cholinergics > topical /alpha2 agonists > beta blockerscarbonic anhydrase inhibitors
Topical tolerability: Beta blockers > prostaglandins > topical > alpha2 agonists > cholinergic drugscarbonic anhydrase inhibitors
Compliance: Beta blockers/prostaglandins > topical /alpha2 agonists > cholinergic drugscarbonic anhydrase inhibitors
Table 3: Characteristics of glaucoma leading to poor compliance
Chronic disease requiring long-term therapy
Expense of treatment
Inconvenience of treatment
Benefits of treatment not apparent
Local side-effects of treatment
Systemic side-effects of treatment
There are three types of professional memberships:
- Free professional membership
- Associate professional membership
- Full professional membership
>> Free Professional Membership
This membership is open to all professionals with an interest in glaucoma.
As a free professional member, you will
- be able to order our literature free of charge and receive news from us when new leaflets are published or when awareness campaigns and other projects are launched,
- receive copies of our quarterly IGA News (magazine) to put in your waiting area.
The only requirement for continued free professional membership of the IGA is the use of our services.
>> Associate and Full Professional Memberships
As a professional member, you will receive:
- a full professional information pack including a membership card (you will be able to order our literature free of charge)
- news about new patient materials, awareness campaigns and other projects
- quarterly editions of the IGA News
- an invitation to attend the Annual General Meeting of the IGA in March,
- the opportunity to vote in the election of the Council Members of the Association and on the resolutions before the meeting
You will also be able to place resolutions before the Annual General Meeting, help define the policies of the Association and submit your application to become a Trustee.
Associate Professional Member £25.00
This type of IGA Professional membership is intended for members of professional bodies allied to ophthalmology such as the Royal College of Nursing or the Royal College of General Practitioners.
I would like to become an Association Professional Member of the IGA
Full Professional Member Annual Subscription £45.00
Full professional membership of the International Glaucoma Association is intended for members of ophthalmic and optometric professional bodies such as the Royal College of Ophthalmologists or the College of Optometrists.
I would like to become a Full Professional Member of the IGA
All Professional Memberships of the International Glaucoma Association are voting memberships and as such each member must agree to take on a maximum £5 liability in the event of the Association becoming insolvent.
If a member does not wish to take on this liability (which results from the International Glaucoma Association being a company limited by guarantee), s/he may request removal from the register of voting members, which will remove the liability.