Tuesday, 27 May 2014
Friday, 23 May 2014
Australian researchers have successfully tested a gene therapy for age-related macular degeneration (AMD) which could mean the end of regular intravitreal injections for patients living with the condition.
The initial results of an ongoing trial in 40 patients with wet-AMD were presented at the recent annual meeting for the Association for Research in Vision and Ophthalmology in Orlando, Florida.
The first data from eight of the patients show that the therapy is safe and was well tolerated. Six of the eight who received the treatment (the other two received placebo) showed no loss of visual acuity, retinal detachment or systemic or intraocular inflammation up to a year after treatment.
The approach works by injecting a modified virus underneath the retina, which then delivers its genetic payload – which interferes with the production of a growth factor involved in the condition, VEGF.
Professor Ian Constable, of the Lions Eye Institute in Perth, Australia, and principle investigator, told Medical Xpress: “The gene therapy involves a single injection of a modified and harmless version of a virus containing a specific gene that stimulates supply of a protein which then blocks over-production of VEGF.”
The data also suggest that the gene therapy does not interfere with previous or subsequent injections of the widely used anti-VEGF treatment, ranibizumab. These positive initial results mean the treatment can advance to larger trials.
Professor Constable added: “After the Perth trial, multi-centre studies will have to be run in the United States and FDA (US Food and Drug Administration) approval sought, but we believe we are on track to test the investigational therapy in more patients, and, if proven safe and effective, make it widely available.”
Wednesday, 14 May 2014
9th - 15th June 2014
Action for sight - Book an eye health check
This year’s National Glaucoma Awareness Week 2014 is urging people to take Action for Sight, and have regular eye tests, particularly if they are at an increased risk of developing glaucoma.
People of African-Caribbean origin are four times more likely to develop the condition, and are more likely for it to appear earlier and for it to be more severe, when compared to people of European origin.
Early detection and treatment literally saves sight, as over 90% of individuals who are diagnosed early will retain useful sight for life. Despite such promising results, it is estimated that over 50% of cases of glaucoma remain undetected in the UK.
Awareness and regular eye health checks are critical. Glaucoma is one of the leading causes of preventable blindness. There are no early symptoms and it isn’t until the condition is fairly advanced that people recognise that there is something wrong with their vision. Once vision is lost, it cannot be recovered. A simple eye health check can pick up the condition early and treatment, which most commonly includes taking eye drops, means most people will maintain sight for life.
The IGA will be supporting the Action for Sight campaign through awareness packs which will be distributed via hospitals, opticians, and through our members and volunteers. Advertising at bus shelters in London and promotions with The Voice newspaper and Nigerian Watch newspaper and website will focus on the increased need for the African-Caribbean population to book an eye test. The campaign will also be supported by the launch of new research into general awareness and understanding of glaucoma.
For further information about the week, please write to Karen Brewer (by post or email email@example.com, or phone 01233 64 81 69- See more at: http://www.glaucoma-association.com/blog/national-glaucoma-awareness-week-action-for-sight-2014.html#sthash.HFg7ADrZ.dpuf
Matheson Optometrists also have a wealth of information about glaucoma at http://www.matheson-optometrists.com/glaucoma/glaucoma_what_is.html
Tuesday, 13 May 2014
Scientists mapping connections between neurons in a mouse eye may have discovered how the retina is able to detect movement.
Researchers have known since the 1960s that the retina can respond to motion before any signal is passed onto the brain, and that the mechanisms were sensitive to direction. But exactly how they worked remained unclear.
Now a team in the US believe it may be determined by how three types of cell are hardwired together in ‘motion detector’ circuits, which are able to detect movement in a ‘preferred’ direction.
A team of researchers, led by H. Sebastian Seung at the Massachussets Institute of Technology, used a crowdsourcing game to map the dense network of neural connections.
Crowdsourcing, or ‘citizen science’, is an increasingly popular ‘divide and conquer’ approach to large scale analysis and has been used previously to identify individual galaxies from maps of millions, and even to identify whale calls.
By breaking down intricate electron microscope scans of retinal tissue into smaller segments, bitesized blocks less than five microns across could be processed by volunteers using an online game they developed, called EyeWire.
EyeWire has already recruited more than 120,000 members of the public to help map the connections. The volunteer ‘citizen neuroscientists’ colour coded branches of the connections between neurons, guided by artificial intelligence as they go.
So far, the result is the highest resolution of the branching connections between the different types of neurons in the eye, in particular, starburst amacrine cells (SACs) and two types of bipolar cells (BPs).
Clusters of these neurons are arranged like circuits in the retina, with the two types of BPs connected to an SAC at the centre. The researchers say that the structure reveals an inbuilt time-delay switch which could account for motion detection, with the two BPs needed to fire to activate the central SAC.
Time delay switch
The innermost (slow) BP cells have a slight delay when firing, whereas the outermost (fast) BP cells do not. It is only when the signals from the both BP cells reach the centre of the circuit, the SAC, at the same time that they activate it.
If the direction of motion corresponds to the orientation of the neurons (ie which direction the circuit is ‘pointing’) then the signal moves from the centre outwards. The slow BP is activated first – like a slow-burning fuse – followed shortly after by the fast BP, and both signals arrive at the same time, activating the SAC.
The team think that this mechanism could explain how the retina is able to detect motion, although experiments are now needed to confirm the theory. They are also cautious that other neuron types may be involved.
Speaking to Scientific American about the project late last year, Professor Seung said: “Neurons come in many cell types, and one of the important tasks in neuroscience today is to identify and enumerate all these different types of neurons in the brain. Nobody knows how many there are... we have to combine human intelligence and artificial intelligence in order to solve this problem.”
The research is reported in Nature.
IMAGE: Rachel Prentki/Eyewire
A strict regimen of monthly injections may not be necessary to counteract the effects of AMD, according to new research.
Researchers looking at 231 patients with the the neovascular, or ‘wet’, form of the condition found that they were able to reduce the number of injections a patient received over a three-and-a-half year period.
Using a Treat and Extend Regimen (TER) approach, they adapted the number of injections a patient received based on their response to the therapy. The number of intravitreal injections was reduced from one per month to an average of just over eight injections per year.
The research was presented at the annual meeting for the Association for Research in Vision and Ophthalmology (ARVO), in Orlando, Florida, earlier this week (May 5)
Two research groups have successfully generated retinal cells using non-embryonic stem cells. The techniques could advance regenerative medicine by providing the cells and tissues needed to treat a range of degenerative eye conditions.
Both groups presented their research at the annual meeting for the Association for Research in Vision and Ophthalmology (ARVO), in Orlando, Florida, earlier this week (May 5).
A Chinese team reported they reprogrammed cells taken from the front of a patient’s eye to generate induced pluripotent stem cells (iPSCs). They were then able to instruct these reprogrammed cells to develop into retinal progenitor cells, the precursors for the different types of cell that make up the retina.
The second group, from north east England, reported how layered retinal tissue can be generated from different types of stem cells with the addition of a growth hormone, insulin-like growth factor (IGF).
Using reprogrammed adult cells (iPSCs), as well as embryonic stem cells (ESCs), they were able to reliably generate layered retinal tissue. Introducing IGF as the cells matured created proto-structures ‘reminiscent of developing human retina’. The researchers report that these ‘ocular-like structures’ included RPE cells and neural retina, as well as other elements such as cells of the lens and cornea.
The group say that the approach offers ‘exciting new opportunities to study retinal development and disease’ as well as providing a source of basic materials for transplant and further research.
Saturday, 10 May 2014
Anne Preston, the editor of the the St Lukes Church in Grayshott handed over £95 raised at “Lent Lunches” this year to Andrew Matheson at our grayshott practice on tuesday 6th May
These funds will be used towards the cost of supplying new spectacles which will be taken on the Returning Vision trips to Malawi, Romania and Moldova in the near future. All donations and second hand spectacles can be left at the Matheson Optometrists practice in Grayshott, or at any of our other 6 practices in Hampshire .
Matheson Optometrists recently were presented with the Optometrist of the Year Award in the Optician Awards ceremony in London in April this year
Wednesday, 7 May 2014
Hosted by the Macular Society Andrew Matheson will be holding a talk/ presentation at the Haslewey Centre in Haslemere on Friday 6th June 2014 at 2pm. The Macular Society have booked a larger room, so there should be space for all who are interested to come along and find out what makes us different!