lowvisionnews.org – the first six months

As the year draws to a close, I have been looking at the stats for this blog. Since starting on June 24th 2009, there have been 2,021 visits to the blog posts – an average of 58 readers per post.

The top five most visited posts (excluding the ‘about’ page) were:
2008 Journal impact factors
Sony Reader: a missed opportunity for low vision users
Opinion piece: Low vision care in a state funded health system
What is the future of assistive devices for the visually impaired?
2009 Conference previews

I have had some very interesting emails and discussions with people who have read the blog: professionals and service users; researchers and clinicians. In 2010 I will continue posting research and conference news of interest to low vision specialists and people with visual impairment.

Any suggestions for future posts, or comments on the frequency of posts (initially two posts per week, now generally one post each week) will be gratefully received – the “comments” section is open.

Finally, I wish every reader of lowvisionnews.org a very happy new year.

Crystal ball gazing: gene therapy, stem cells or retinal prostheses?

There is a nice trio of papers in the current issue of the journal Eye which review the current state of research in gene therapy, stem cell therapy, and retinal prostheses. They are all well written and offer a balanced view of the likelihood of each of these techniques being useful for people with retinal disease.

The gene therapy paper, by Jim Bainbridge of the Moorfields/UCL Institute of Ophthalmology centre, summarises the principles behind gene therapy and briefly describes the results of the Moorfields, University of Pennsylvania and Childrens Hospital of Philadelphia trials. These trials were all for people with a rare but well understood degeneration called Leber’s Congenital Amaurosis. Each of the groups report improvement on some measures of function, although not visual acuity. Bainbridge suggests that the treatment will be most effective when applied very early in the disease process when there are still a large number of cells which can be “rescued”. He also claims it will be easier to treat diseases which affect the retinal pigment epithelium than the photoreceptors, so for example Stargardt disease will be less easy to treat with this technique.

The stem cell paper is by Johnson and colleagues from Cambridge. They describe some of their laboratory work on animals with induced glaucoma. Whilst these results are encouraging there are many technical issues which need to be addressed, which they discuss. Of course there are also very large ethical and regulatory issues with stem cell therapy, particularly for embryonically derived stem cells.

The final paper summarises some of the work on retinal prosthesis (“artificial retinas” implanted into people with no vision from diseases such as retinitis pigmentosa. There are several different technologies which are described in this paper, and the authors state that three different commercial products are likely to appear by the end of 2010 (from Second Sight, Intelligent Medical Implants and from Retina Implant). They also describe a very interesting approach used by a group at Imperial College, London, where viral engineering can make retinal ganglion cells or bipolar cells light sensitive (i.e. which can make nerve cells act like photoreceptors). This sounds very exciting, although no in vivo animal trials of this technology have yet been performed, let alone human trials.

Together the three articles provide an interesting overview of cutting edge science at present. I imagine that in the next 5-10 years all of these methods will be used more and more for people with eye disease. I wouldn’t like to guess which will end up being the most successful approach, but think we should all watch these emerging fields of science with interest.

Book review: “Low Vision Rehabilitation: A practical guide for occupational therapists” by Scheiman, Schieman and Whittaker

This is an excellent overview of low vision rehabilitation which is intended for the Occupational Therapist but would be of equal benefit to educators, low vision support workers, ophthalmic technicians, clinicians new to low vision rehab, or families of people with visual impairment.

It starts with a very clear introduction to epidemiology of visual impairment, basic anatomy and optics, and the pathophysiology or common causes of low vision. Whilst this overview would be insufficient for an optometry student revising for exams, it ensures that the intended reader is not left behind by terms in the rest of the book.

The second section presents the optometric and occupational therapy models of low vision evaluation. The bulk of the book, rather optimistically entitled “treatment”, covers optical low vision devices, nonoptical devices, electronic magnifers, environmental modifications and computer technology in low vision rehab. It also includes an excellent chapter on diabetes self-management which is often overlooked in other textbooks. The final section describes pratice management for the low vision practitioner.

I have some reservations over the section entitled “treatment”; as low vision professionals we are able to ameliorate some of the difficulties people with visual impairment experience but I really don’t think it’s fair to say that we treat anything. This may sound like a pedantic point, but I think it is misleading to our clients/patients/service users if they think they are being referred for a low vision “treatment”. I was also disappointed to see quite heavy used of low vision simulation photographs in the text: I think it is now reasonably well accepted that a photo of a scene with a black pattern in the middle is not a realistic simulation of vision with a macular scotoma, for example.

However, these are minor gripes about what remains an extremely readable, useful overview of low vision rehabilitation which may well find readers beyond its intended audience.

Links: amazon.com amazon.co.uk amazon.ca