Crystal Ball: Age related macular degeneration
IN BRIEF - 1ST DECEMBER 2016
Dr Clare O'Donnell, head of eye sciences at Optegra Eye Health Care, looks at how treatments for age related macular degeneration will evolve in the coming years.
The state of play
Age related macular degeneration (AMD) is a condition that affects a part of the eye called the macula, which is responsible for our fine vision. If the macula begins to degenerate, the sufferer’s ability to perceive fine details deteriorates over time. AMD is the leading cause of irreversible visual impairment in people aged over 60, with 10-15% of those affected suffering severe vision loss. In the coming decades, as life expectancy continues to rise, tackling this condition will become increasingly important.
There are two main types of AMD: ‘wet’ and ‘dry’. Wet AMD is more aggressive and can progress quite rapidly. Dry AMD tends to be less severe and progresses at a slower pace. For early stage dry AMD, monitoring and lifestyle changes such as modifying diet and stopping smoking are all that are needed. For wet AMD, however, things are different—and for many years the prognosis for those affected was poor. However, recent advances in treatment and non-invasive imaging technologies used for retinal diagnosis have begun to revolutionise the field. We can now see the macula at much higher resolutions than ever before, and even create virtual 3D scans to show what is going on below the surface of the retina. This has helped hugely in early diagnosis of the disease, which is absolutely vital.
One area of research that led to real progress in treatment involves a technique called intravitreal injections, in which we inject drugs into the jellylike substance in the eye known as the vitreous.
Wet AMD can cause the growth of new but weak blood vessels under the surface of the retina. These can leak fluid, which disrupts the workings of the macula, which has a serious impact on vision. Intravitreal injections allow us to treat this by injecting the necessary medicine straight into the eye.
One new and really exciting approach being developed involves a combination of intravitreal injections with other therapies, such as low dosage radiotherapy. These approaches are still in their early days but I believe there are some great treatments that will come from such innovation.
Other advances are being made through our ability to implant miniature telescopes into the eye, which help when the patient’s natural lenses have deteriorated through age or illness. Doing this dramatically increases the eye’s resolving power, which means that the macula is getting the best possible image to work with. The technology already exists, but it is still in its infancy.
On the horizon
If we are looking much further ahead, some of the most promising options we are exploring are based around gene therapy and stem cell therapy. Developing stem cell treatment is a complex and hugely challenging task, but the possibilities if we succeed will be remarkable. This will involve replacing the cells that have been damaged or lost due to AMD by reprograming healthy cells to take over their job. People get very excited about this type of therapy because the potential is enormous—but then so are the challenges in making it work!
Working with our genes also offers what for me would be the perfect long term solution—the ability to identify people at risk of developing AMD before they begin to present any of the symptoms. This might then allow us to develop the appropriate treatment or understand the type of lifestyle modifications required without the patient developing the symptoms at all.
We have started along that road and have made significant progress, but there is still a long way to go.
For more information, visit Optegra