Low Vision News

For low vision specialists and those who consult them

Monthly Archives: January 2010

Local or centralised – which is the best model for low vision care?

Would you rather have a low vision clinic near your house which sees a handful of people with visual impairment every year, or would you prefer to travel many miles to attend a clinic which sees dozens of people every week?

This interesting point of debate came up whilst I was examining a PhD thesis last week. The thesis was in part describing the new community low vision service in Wales (see here for more information) where optometrists in the community receive extra training in low vision and are able to prescribe and dispense low vision aids locally. The scheme has dramatically reduced waiting lists and travel time to low vision appointments, but does mean that people with low vision are seeing practitioners who, whilst trained, are not as experienced as their colleagues in hospital departments who may see low vision patients exclusively.

Travel can be arduous for people with visual impairment, and older people in particular may not be enthusiastic about travelling into a large city where bigger low vision clinics are often located. Having a service in a local area – possibly within walking distance – is extremely useful and may well allow people who will not travel into a specialist centre to be seen.

As long as people are trained, does it matter if they don’t see many patients? There is very little evidence in the low vision field which addresses this topic apart from more specialist techniques (such as the prescription of Peli prisms which are more successful in centres which see more patients). In other areas of medicine, paediatric cardiac surgery is known to have a better outcome with a more experienced surgeon, but there are not clear documented benefits in other areas. Of course this may well be because of the ethical and logistical difficulties in constructing a study to evaluate this.

So would I suggest to a close friend with visual impairment that they see a local optometrist with less experience in low vision, or a city-centre specialist centre where they will see people with more experience in low vision? Of course, I am biased because I work in probably the largest low vision clinic in the world, but my answer would be that it would depend on what my friend’s needs were. If they just needed refractive correction and conventional hand or stand magnifiers I would definitely suggest the local service. However, if they needed spectacle mounted telescopes, field expansion devices, minifiers, or other complicated devices, or if they were a child or had specific employment difficulties, I would suggest they were seen in a larger clinic.

I think it is true that ‘the more the better’ applies when referring to low vision services: we really need more people providing services and easier access for patients to our clinics. The ideal model would involve local “basic” low vision care with onward referral to regional specialist centres for more advanced care. I think the Welsh scheme is pretty close to optimal.


Causes of visual impairment in children

I have just read an interesting research article in Eye, the journal of the Royal College of Ophthalmologists in the UK. The authors look at the cause of visual impairment in children who have been registered as sight impaired in one specialist paediatric ophthalmology clinic in North West England.

The most common cause of vision loss was cortical visual impairment (27%) and optic atrophy (16%). These figures are very similar to other reports from Europe or the USA.

Of the 256 children who were registered as sight impaired (previously called partially sighted in the UK) or severely sight impaired (previously registered blind), only 7 cases were thought to be avoidable. These were two cases of retinopathy of prematurity (which can be treated if detected and managed early enough); two cases of amblyopia (usually treatable with glasses and/or patching if caught early enough); two cases of trauma and one case of non-accidental injury (child abuse).

Only 10 of the children (4%) had no sight at all. This is an important figure as it shows that the overwhelming majority of children registered as sight impaired in the UK could potentially benefit from a low vision assessment. I am aware that as a low vision specialist I am biased, but I would like to have seen some discussion of this in the paper (and some check on whether these children did all receive low vision intervention).

The authors show that children with visual impairment are more likely to come from deprived areas than their peers with good vision. This is not really discussed further by the authors and I would like to know why they feel this should be the case, and (more importantly) whether targeted public health education programmes in areas of greater deprivation would be wise.

This paper is most interesting when the numbers are compared to the global picture, and the authors summarise some of these data well. It is sobering to remember that 95% of sight impaired children in the world are born in Africa, Latin America or Asia, and that many of these children will have treatable or avoidable causes of visual loss such as vitamin A deficiency, corneal scarring or cataract.

The authors show a small increase in the number of children who are registered as sight impaired in their clinic although the numbers are probably too small for meaningful analysis. They do speculate that as neonatal care for premature babies improves there may be an increase in the number of children with cerebral visual impairment surviving, so it is possible that the number of children visually impaired may increase. However, the number of children with visual problems in Europe and the USA remains tiny when compared to the developing world.

2010 conference previews

At the start of the year, I like to plan which events and conferences I intend to visit in the coming year. Although we’ll have to wait until 2011 for the once-every-three-year International Conference on Low Vision, there are several interesting meetings coming up.

In May, the Association for Research in Vision and Ophthalmology (ARVO) annual meeting will take place in Fort Lauderdale, Florida. This is by far the biggest vision meeting of the year – typically there are 8,000 presentations and 12,000 delegates. This conference covers all areas of clinical vision research but tends to have three or four low vision poster and paper sessions. It is also an excellent conference for networking and for finding out about the latest research trials of treatment of eye disease: for example, in 2008 the results of the gene therapy trials for Leber’s amaurosis were both first presented there.

I have been invited to speak at the Canadian Ophthalmology Society in Quebec City in late June. This is a conference which I have not visited before (being neither Canadian nor an Ophthalmologist) but is sounds as if this meeting will also have a substantial low vision content.

As frequent readers will know, I very much enjoyed the Envision conference in 2009. This year’s Envision meeting will be in San Antonio, Texas, from September 22nd-25th. Envision has a mix of clinical teaching and research seminars, and although it’s a relatively small meeting there are parallel sessions so the programme is very busy. More information on this meeting can be found at www.envisionconference.org.

I am very excited by a new European low vision meeting which is taking place for the first time in Valladodid, Spain, this October. Although there are not many details on their website yet, I think this could be an excellent meeting. (Note their website defaults to Spanish: the English button is towards the top right of the screen; and see disclaimer below).

More locally, I think it’s about time I made another visit to Sight Village in July (link) – the largest British trade fair of low vision aids and electronic devices – in order to check out new developments in this field.

Looking ahead to 2011, I’m slightly concerned that the organisers of the Vision 2011 meeting haven’t yet prepared their website or sent a call for abstracts yet, but I’m sure that will follow soon…

As always, I’ll update my blog with news from each of these meetings. Who knows, in between going to conferences (and collecting thousands of air miles, by the look of things) I may even get some work done!

Disclaimer: I am on the scientific committee for the European low vision meeting, but have no commercial connection with it.