Age-related macular degeneration (AMD) is the most common cause of legal blindness in Australia.
AMD has essentially two forms: “Wet” and “Dry”
Dry AMD
This is the most common form of AMD. Characteristic degenerative lesions called drusen are seen in the macula – the area of the retina that we use for fine, detailed central vision and reading.
Over time these drusen enlarge and can be associated with vision loss when they cause the light-detecting cells (called photoreceptors: rods and cones) in the overlying retina to die off.
Dry AMD tends to get very slowly worse over a long time, and most patients retain good vision.
However, dry AMD can get worse quickly, especially if it changes into the “wet” type.
Currently there is no proven effective treatment for dry AMD, but research is ongoing especially into injectable medications, and even oral medications.
Wet AMD
Although wet AMD is less common, we can now treat it effectively if detected in the early stages.
Wet AMD is characterised by the development of a “scarring” blood vessel, or choroidal neovascular membrane. This leaks plasma/fluid, blood fats, and can even bleed. It stimulates the formation of scarring and retinal tissue overlying the lesion dies off, leaving a grey spot or blur or distorted area right in the centre of your vision.
Left untreated, we know that wet AMD causes irreversible central vision loss over about 6 months.
However, treatment for wet AMD is effective: regular injections of special drugs can stop your vision from getting worse in 90% of patients. About 30% of people will experience improved vision (and this is typically maintained). A small percentage of people do not respond to treatment and their vision continues to slowly decline.
For all types of AMD, we recommend:
- stop smoking
- eat a diet rich in fish and green, leafy vegetables
- take regular exercise
- monitor your vision at home using an Amsler grid (ask our staff for one of these)
Early detection and treatment are crucial to preserving vision in the long term. How’s your macula?