Research and possible future treatments for Usher
Sense's position on research into Usher syndrome and potential treatments
There is no cure for Usher syndrome. There are treatments available that protect or maximise the sight, hearing and balance that people do have.
Research is taking place into new treatments but it will take a long time and there is no guarantee about the results. Sense is in touch with lots of people with Usher syndrome. Some people are very interested in treatments and research – they want to see research activity and new treatments or cures. Others are not interested in new treatments or cures but may want to protect their existing sight, hearing and balance.
Sense wants people to make informed decisions about tests, treatments and research. For this to happen people must have really good information. Sense can make information available. Sense cannot give medical advice.
Sense thinks it is good news that research is taking place into Usher syndrome, and that some people with Usher syndrome (and their families) want to be involved. Individuals have the right to choose whether they take part in research. People with Usher syndrome, and their families, should be involved in discussions about what research takes place, and how it is carried out. The way a person communicates must not be a barrier to getting involved in research.
It is important that people with Usher Syndrome, and their families, can easily access the medical support they need.
About Usher research
There is a wide range of research going on into Usher syndrome – whether into the genetic causes of Usher or possible future treatments.
Information about some of the clinical trials currently being carried out is contained in this section. It is not an exhaustive list and there may be other research being carried out.
Typically, the development of a medical treatment or a particular drug takes many years. Promising news will often appear in the media during development, and often years before any human clinical trials, but this is often a long time before the treatment may be available.
Types of clinical trials relating to Usher syndrome
The focus of existing clinical trials relating to people with Usher is vision and the retina.
A number of research centres around the world are developing retinal implants. At its most simple level this can be considered to be the vision equivalent of cochlear implants.
The most common technique being trialled offers people with Retinitis pigmentosa (RP) a small video camera that is placed behind their glasses. This sends visual signals to a device implanted on the retina at the back of the eye. This device, in turn, electronically signals the remaining cells in the retina which passes the signals down the optic nerve for processing in the brain.
The first retinal implant is now commercially available in the USA but researchers are continuing to work on and trial improved, more effective devices.
One of the great advantages of retinal implants is that they could benefit people with advanced RP as it bypasses the photoreceptors affected.
The principle of gene therapy is that a gene is inserted into a patient’s retinal cells.
The intention is to inject a correctly working gene directly into the affected area of the retina. The cells should then begin to work properly and further damage to the retina will hopefully be prevented. It is important to know which gene causes Usher in each patient so that the right gene therapy is used. Gene therapy has not yet been designed for all the Usher genes.
There have been two clinical trials of gene therapy to treat Leber congenital amaurosis, a type of inherited degeneration of the retina very similar to RP, but which begins much earlier in life. Results have been encouraging so far and have shown improvements to vision over periods of up to three years in some, but not all, patients
There is a long way to go but gene therapy could become a useful treatment option for RP in the future.
Stem cell therapy
Stem cells are cells that can divide and give rise to other cell types, which could fulfil a variety of functions. They can potentially replace damaged and missing cells from different kinds of organs, including the eye. Tissues such as the retina do not divide to produce new cells and so retinal cells are not naturally replaced once damaged by RP.
Retinal stem cell therapy aims to use stem cells to replace damaged or lost cells in the retina. The intention is to ‘persuade’ the stem cells, by growing them in special conditions in a laboratory, to turn into the rod and cone photoreceptor cells that are affected by RP. including the rods and cones affected by RP. These new cells will then be transplanted into the retina.
Although human clinical trials have yet to begin for patients with RP, they have begun for those with another eye condition called Stargardt Disease. That involves cells which are easier to grow in the laboratory. There are a number of challenges to be overcome before clinical trials take place to replace the more complex rod and cone cells that are central to slowing or reversing RP take place.
Growth factors are naturally occurring chemicals that support cells to grow and repair themselves. Researchers are exploring the effective use of them on their own as well as combined with gene and stem cell therapies.
One of the growth factors being focussed on is called CNTF (Ciliary Neurotrophic Factor). The role of CNTF is to protect nerve cells. It is delivered to the retina via a tiny implanted device which releases the CNTF.
Early research has shown that CNTF can slow deterioration of the retina in animals with RP. Human clinical trials are now underway with patients with both early stage and late stage RP.
Created: February 2016
Review due: February 2018
First published: Wednesday 2 December 2015
Updated: Monday 16 January 2017