Macular Degeneration is eye diseases that affect the retina, causing progressive loss of the central (reading) vision. It does not cause total blindness as the surrounding (side) vision remains normal, but impairs a person’s ability to read, recognise faces, drive, and makes it difficult to recognise colours and contrasts.
Macular degeneration commonly affects people over 50 years of age and is referred to as ‘age-related macular degeneration’ or AMD. There is currently no cure for AMD, and treatment efforts are directed at maintaining useful central vision for as long as possible. AMD is the leading cause of vision loss in the western world, accounting for almost 50% of all visually impaired cases.
The causes of AMD are not fully understood, however the major risk factor is increasing age. The disease seems to cluster in certain families, suggesting that some are more genetically susceptible than others.
Types of AMD
There are two types of AMD, the dry form and the wet form.Both forms start in the Retinal Pigment Epithelium (RPE) – the layer of cells that nourish the retina.
Dry AMD is the most common, accounting for 85 – 90% of all cases. It develops gradually and doesn’t cause sudden vision loss or distortion. When RPE cells die the retinal cells above also die, leading to patches of ‘missing’ retina. Read more about our research in Dry AMD here: Dry AMD research at LEI.
Wet AMD is the most severe, accounting for 10 – 15% of cases. It develops when new blood vessels grow wildly beneath the retina. These vessels may bleed or leak fluid, causing scarring of the retina and loss of vision. When left untreated, rapid and severe loss of the central vision can occur within a short period of time.
The main symptom of AMD is blurring of the central vision, with many people experiencing difficulty when reading. People also experience blurred, dark, or empty spots, similar to the after effect of looking into a flashbulb. A frequent and important symptom is distortion, straight lines such as door frames or street poles may appear bent or wavy.
Regular eye examinations are the best way to detect AMD, this should be conducted by an Ophthalmologist. If you experience any of the symptoms above, please make an appointment as soon as possible.
Research suggests there are things that can be done to reduce the risk of developing AMD, including:
eat a diet rich in fresh fruit and dark green leafy vegetables,
increase your intake of fish and other omega rich foods,
supplement your diet with vitamins, minerals and antioxidants,
protect your eyes from ultraviolet light,
check your vision regularly with your doctor.
There is currently no cure for AMD, and treatment efforts are directed at maintaining useful central vision for as long as possible. Treatment varies depending on the type of AMD and individual characteristics of the condition.
Various treatments available for wet AMD include:
Ranibizumad (Lucentis), Aflibercept (Eylea) and Bevacizumab (Avastin)drugs are the most common treatments used. These drugs are injected into the vitreous cavity of the eye, reducing leakage from the blood vessels under the retina.
Photodynamic Therapy (PDT) is a specialised laser therapy combining injection of a photosensitive drug called Verteporfin into the blood stream followed by laser treatment.
Laser Photocoagulation is a concentrated beam of high energy laser light, directed onto the retina, to seal the leaky blood vessels.A consultation with an ophthalmologist will determine which treatment is appropriate for each case.
There are currently no proven treatments to reverse the effects of dry AMD. Some vitamins, minerals and antioxidants ‘may’ slow down the progression of early stage of AMD. There are also several clinical trials being conducted at the Lions Eye Institute examining new laser and drug treatments for dry AMD. These experimental options need to be discussed with an ophthalmologist involved in dry AMD clinical trial.