Many forms of sight loss are caused by degeneration of the layer of tissue at the back of the eye known as the retina. This can lead to variable levels of vision loss which is specific to each person, and depending on the condition they have, the variance can even be within the same families with the same gene type. Retina Australia believes it is vital to understand the condition that affects you or your family members, so that you can make informed decisions about your eye care and the supports that may be needed now and into the future.
Researchers all over the world are investigating inherited retinal diseases (IRDs), also referred to as retinal dystrophies. They are continuously identifying the causative genes and symptoms, with the intention of developing treatments and, ultimately, cures.
Some conditions, such as forms of age-related macular degeneration and diabetes related vision loss, can be successfully treated. For some rare, genetic and inherited conditions or IRDs as they are often described, we are still in the early investigative stages; for others we are moving towards human clinical trials, and even towards potential treatments.
Initially researchers were focused on gene therapies solely, but the development of innovative technologies and a better understanding of biology has meant that there are now many more pillars of research offering hope for treatment.
Genes and Gene Therapy
Gene therapies could treat inherited retinal disease by repairing the abnormal gene. The disease-causing faulty gene is replaced by putting a “normal” copy into an affected person’s cells. Often this can be done by using a harmless virus that has been genetically modified to carry human DNA.
The eye is an ideal organ for gene therapy as it is well protected from the body’s immune response. Early successes at clinical trial stage are paving the way for treatments for both inherited and non-inherited forms of blindness in the near future.
Stem Cell Therapy and Regenerative Medicine
Stem cell technology has great potential for improving the sight of people with a vision impairment. It would aim to replace defective photoreceptors that have been lost due to degeneration, so that useful vision could be restored.
A number of studies are being undertaken to develop new therapies to treat or prevent loss of vision. Researchers are developing our understanding of how different types of stem cells behave, and how best to harness their potential in the eye. Stem cells are not a one-stop, generic cure, but they do hold exciting potential for vision repair.
Retina Implant Technology or Artificial Vision
Retina implant technology involves the use of microelectronics and microchip electrodes surgically implanted into the back of the eye (retina) to restore the function of damaged photoreceptors. Photoreceptors respond to light and pass an electrical signal to nerve cells in the eye, and then to the brain where the signal is perceived as vision.
Various retinal implant technology projects are underway around the world, including the Australian Bionic Eye Project.
Novel Drug Therapy including Neuroprotection & Antioxidants
Scientific research has led to a better understanding of the causes of a large number of retinal dystrophies, and to the exploration of novel drug therapies to compensate for the defect causing vision loss.
Another approach involves using drugs to slow the death of photoreceptor cells, preventing further vision loss and preserving vision. Many of these drugs are repurposed drugs: they may already be used for a different disease and are being tested for their effectiveness in the eye. These therapies may have the potential to be administered to many different forms of IRD, because they focus on arresting the process of cell death.
Epidemiology or Population Studies
These include the study of individuals taken from the general population who share a common characteristic, such as a health condition. These studies help scientists to understand the course of disease in different people and populations.