In the past couple of months there have been several news articles talking about optogenetics and its use as a treatment for eye conditions including Stargardt's, Retinitis Pigmentosa and Macula Degeneration. I hadn't come across the term so I thought I'd do some research into what exactly it is, since I am known to have to know everything about everything!
Optogenetics is a new technology, first discussed in 2004, using the ideas of neuroscience and microbial biology. The basic idea of optogentics is that light can activate and deactivate cells. It was observing algae that led to the lightbulb moment (excuse the pun). Algae would swim towards light, and scientists found a protein that was activated by the light and causing its behaviour.
Scientists then came up with the idea to remove the DNA (protein) from the algae, use gene therapy (attach it to a virus so it can be put into other animals) and then inserting into the animal cell. Once it was in the cell, it would replicate and fill the cell with these light sensitive proteins. They could then manipulate the cells using different coloured light. They also had the ability to add these viruses only to certain cells.
This technology is being investigated for brain diseases but also for vision conditions. Below is a TED talk that explains the discovery of optogenetics, how it is being researched and describes its use for vision conditions. Basically what it says is that even though the photoreceptor cells are damaged, light can still get into the retina. Optogenetics installs cells to act as a 'camera'. The video shows an experiment they have done with mice that, I must admit, got me a little emotional thinking about the possibility of seeing things again!
Below are links to optogenetics and vision articles.
Blindness and visual impairment seems to be in the media quite a bit lately. I've gathered the most recent updates for you all to check out.
A study in the UK has successfully inserted implants into three patients retinas. The patients treated had Retinitis Pigmentosa and saw immediate results once the implant was in use. This website has an amazing picture of the implant in the retina and also explains the technology.
I've previously mentioned Advanced Cell Technology and their stem cells trials. The latest on the trial is that they were given approval to increase the dosage of stem cells and recruit further Stargardt's patients. This is great news. This trial is a phase 1 study which is looking at finding the maximum dose that can be tolerated and the safety of the technology. All is looking positive for stem cells!
Gene therapy is another new treatment that is seeing exciting results. A US university has successfully treated 12 patients who have another inherited retinal disease - Leber's Congential Amaurosis (LCA). The treatment involved injecting a virus with copies of the 'normal' gene into the eye. The patients treated are reported to be able to make out shapes, recognise faces and read large print. This could also be a possibility for other inherited eye diseases.
I was kindly sent a powerpoint presentation from a university in the Netherlands about recent studies of gene therapy for Stargardt's Disease and another genetic disease. Coincidentally, I have been working with a dutch medical student (who is a great friend!) and we had some fun translating the presentation into English for you all to have a look at.
I've been following the Foundation Fighting Blindness (@gihtblindness) on Twitter over the past few weeks. This weekend they have held Vision 2011 conference in the US. They have been updating their posts regularly and I have found out some interesting facts. The following are the tweets that I found really interesting:
1. "Q: animal trials - any reversal of vision loss 4 Stargardt? A: going that direction, but nothing yet showing definite restoration." 2. "Dr. Jacque Duncan (involved in retinal disease clinical trial) said that retinal degeneration is usually slow so it's hard to detect changes in 2-3 year studies."
3. "From Stem Cell session panel - Must easier to save retinal cells than replace them."
4. "Gen etc testing and thorough exams important because many diseases look alike.. Cone rod, Stargardt, Best Disease can look similar."
5. "About 50% of cone rod dystrophy caused by ABCA4 - same gene that causes majority of Stargardt disease."
4. A quote from John Wellner - "It's a great time in history to be blind; way better than the 1400's". You'd hope so!! The link to the Foundation Fighting Blindness is below.
Check out the latest clinical trail being conducted in the US and France. The research into StarGen has been going on for some time, and below are some links following the progress.
StarGen is a gene therapy developed specifically for Stargardt's. If successful, it would consist of only one treatment directly into the retina which is great news.
Gene therapy involves treatment of the actual affected cells of the body. It can remove damaged genes, alter the genes or insert genes into a particular cell, in this case in the retina. Gene therapy studies are focusing predominantly on hereditary diseases, such as Stargardt's. Some problems noted with gene therapy include immunosuppresion and problems with viruses that may be used to carry the gene.
It is seeming like a treatment is inevitable and likely to be in the near future, so it is important for us all to keep our spirits up and focus on enjoying the experiences we are going through, whether they be positive or negative!!
