Glaucoma 2007 (page 4)

December 7, 2007

blah

1, 2, 3, 4, 5

Raising awareness
So we've looked at the newest and most popular treatments for glaucoma, but how are we doing in raising awareness of the disease amongst the general public? "Glaucoma as a disease is very badly understood by the public but it is up to us to use patients as a communication tool," urged Dr Shaarawy. "One of the most effective yet the simplest method for improving glaucoma management and referrals is for the doctor to put some effort into passing the message to the public through the patient, who will then transmit information about the disease and treatments to their friends and family."

In order to raise public awareness of glaucoma, the World Glaucoma Association has announced World Glaucoma Day, to take place on the 6th March 2008. Dr Shaarawy is enthusiastic about this and is involved in organizing a number of events. "In Geneva, for example, we are planning an open day at our clinic, where patients can have a free, simplified examination where we will look at their optic nerve head, optic nerves, visual acuity and IOP," he explained. "In the city centre we are going to run a mobile unit offering the public an examination onsite and we have contacted the local media who will run articles in newspapers highlighting the importance of glaucoma screening. We are also going to run interviews with specialists in the local and national press and we have a team taking part in the Geneva marathon to raise awareness," he enthused.

                      

      

Whether other countries will follow the Swiss example remains to be seen. It will certainly be interesting to see what impact the various initiatives arising from World Glaucoma Day will have.

Are we reaching the right patients?
The practice of screening and referral is consistently under scrutiny, largely because a large proportion of glaucoma sufferers are still undiagnosed. Dr Mermoud, however, believes that the Swiss system is effective as it stands, "In Switzerland, patients are very well followed by their own ophthalmologist and are sent to the glaucoma centre when they need further investigation or surgical treatment."

However, in the UK, for example, a very different picture is being portrayed by some. In an article published in Ophthalmology Times Europe9 earlier this year, Dr Asa Ibraheim from the Rotherham Foundation NHS Trust & Sheffield University highlighted the fact that insufficient resources and increasing demand for visual field screening present the biggest obstacles to good glaucoma practice management in the UK. "Visual field screening is an indispensable tool and a prerequisite for proper glaucoma management. However, the current financial constraints within the UK National Health Service (NHS), often means that district hospitals can only afford to train and employ one perimetrist for the task and can only afford one item of equipment (for example one Humphrey Analyser)," he said. With glaucoma accounting for 15% of registered blindness in the UK alone, this is clearly a problem that needs addressing.

Dr Ibraheim believes that adherence to agreed guidelines for field referrals would help enormously and suggests a possible set of useful guidelines:

  • At least one, but preferably two, visual fields should be performed in the first year for all glaucoma patients.

  • More frequent testing may be required for those who have uncontrolled glaucoma.

  • If vision is less than 6/18, reliable field testing is unlikely to be successful and so should not be performed.

  • The age and wellbeing of patients should be considered. Although age discrimination is not allowed, some older patients may not have the necessary capacity to undergo testing.

  • If two or more visual fields show 20% or more false positives, there is little to be gained by re-referring for further testing.

Dr Ibraheim also believes that the UK's current system of prioritization needs improving. "Known cases of glaucoma, which are not well controlled, should take priority and be 'tagged' as appointments that should not be deferred or cancelled," he suggested.

Dr Shaarawy also believes that there are improvements that should be made regarding glaucoma screening, "Instead of screening the public in general, we should probably target those at high risk of glaucoma, such as high myopes, diabetics and patients with a family history of glaucoma."

Diagnosis: the key to success
Having stressed the importance of early screening we also need to look at the instruments used for this purpose. This year there have been some exciting new diagnostic technologies introduced to the market. For example, Heidelberg Engineering's Heidelberg Edge Perimeter (HEP), was launched at this year's World Glaucoma Congress in Singapore. The HEP uses a new stimulus called Flicker Defined Form, which targets M-cells and has been shown to be highly sensitive to functional loss due to early glaucoma. The company believes that, not only does it target early glaucoma, but it is also more comfortable for patients resulting in a higher test-retest reliability than conventional methods.

"…OCT of the anterior segment
has helped to better analyse
some angle pathologies"

Elsewhere, a 3-D computer automated threshold Amsler grid test has been developed which is able to identify abnormalities characteristic of glaucoma in glaucoma suspects whose achromatic Humphrey visual field test was normal. The 3-D test exhibits a grid on a computer screen at a pre-selected greyscale and angular resolution, and allows the subject to trace those areas on the grid that are missing in their visual field using a touch screen. The test's creators, Paul Nazemi and colleagues from Doheny Eye Institute, University of Southern California, USA believe that it is able to pick up on abnormalities that are not found with normal achromatic visual field testing, therefore suggesting that the test could prove useful for early screening.

Despite these new advances, this year has undoubtedly been 'the year of the OCT'. "The introduction of anterior segment OCT (optical coherence tomography) has been very useful for glaucoma diagnostics," remarked Dr Shaarawy and this is confirmed by Dr Mermoud who said, "The OCT of the anterior segment has helped to better analyse some angle pathologies."

1, 2, 3, 4, 5