This week is Macular Degeneration Awareness Week, a week dedicated to educating and providing information on Macular Degeneration and how to reduce the incidence and impact that it has on daily life.
As the name implies, macular degeneration is the degeneration or destruction of the macula which is the light sensitive tissue present near the centre of the retina. The tissue lines the back of the eye and is responsible for sharp, central vision that helps us see the finer details of the object that is straight ahead. Once your central vision is affected, it becomes difficult to perform important tasks such as reading, driving or even recognising faces. As damage to the macula occurs gradually as we get older, it is also known as age-related macular degeneration (AMD). Affecting usually the older age groups of 50 or more, AMD is a major cause of severe vision loss and blindness in Australia.
Types of Macular Degeneration
There are two types of AMD:
- Dry AMD: A more common form of AMD affecting about 90% of patients, dry macular degeneration results from normal aging processes causing thinning of the macular tissues. Apart from thinning, small yellow or white pieces of fatty protein called drusen may also be deposited in the macula hampering its normal functioning. As the thinning or deposition occurs gradually with advancing age, the visual changes are also gradual and can be detected at an early stage by careful monitoring and observation. Some of the early symptoms of dry AMD include blurry or hazy vision and difficulty in recognising faces until they are very close. Early diagnosis can prevent the progression of the disease into the more severe wet form described below.
- Wet AMD: Though less common with only about 10% of those diagnosed with AMD affected, wet AMD is a much more severe form of macular degeneration and is characterised by the formation of abnormal blood vessels beneath the retina. It is also referred to as neovascular AMD due to the formation of new blood vessels under the retina (neo=new). These new blood vessels tend to leak fluid or blood below the macula causing permanent damage to the cells and creating blind spots. The permanent damage occurs at a much faster rate compared to the dry form and thus, early diagnosis and treatment is essential to preserve as much vision as possible. Symptoms include a straight line that appears wavy or black spots in your vision.
High risk factors:
- As aging is the most common cause of macular degeneration, if you are over the age of 50, you should get regular eye check-ups with your optometrist to detect the disease at the earliest possible time as symptoms may not be very obvious in the early stages.
- Smoking: Smoking almost triples the risk of developing AMD, especially the fast progressing wet form.
- Genetics: Family history of AMD tends to increase the risk of the disease in subsequent generations.
- Race: Caucasians are more prone to macular degeneration than Africans or Americans.
- Gender: Females are believed to be at a higher risk as compared to males.
- Other risk factors include hypertension, obesity, high cholesterol, lack of exercise and diets rich in unsaturated fats.
Manifestations of macular degeneration
Apart from the initial symptoms mentioned above, other signs and symptoms of macular degeneration are:
- Both the types of AMD- dry or wet are painless and lead to blurred or hazy vision.
- Particular symptoms of dry AMD include black or grey blind spots in the centre of the visual field and in the case of advanced disease, decreased night vision, inability to read or drive, decrease in the brightness of colours and quality of life affected due to inability to perform useful tasks.
- Specific symptoms related to wet AMD are larger spots of black or grey colour in the central visual field, distorted vision and the size of objects may appear to be different for each eye.
To diagnose macular degeneration, your optometrist or ophthalmologist will perform a complete eye exam in addition to the following diagnostic tests:
- Visual acuity test to check your vision clarity.
- Amsler grid: The straight lines of the checkerboard pattern of this grid appear wavy, missing or distorted to patients having AMD. The Amsler grid is an exam that you can conduct at home on a regular basis. Pick up a grid from your optometrist or through the Macular Disease Foundation Australia
- Angiography to detect abnormal, leaking blood vessels in case of wet AMD.
- Other extensive diagnostic techniques include optical coherence tomography and retinal photography.
Although no cure is yet known to reverse the permanent damage caused to the macular cells, treatment can be aimed to prevent the progression or advancement of the disease to preserve as much vision as possible.
- Wet AMD is best treated with anti-VEGF medication. Anti-VEGF is delivered to the macula region via injection and may need to be administered every 3 months in the early stages to prevent further vision loss. Anti-VEGF works by stopping new blood vessel growth into the macula. New blood vessels leak causing fluid in the area, hence the ‘wet’ prefix.
- Dry AMD may be prevented from advancing to the wet form by taking certain nutritional supplements of Vitamin A, C and E, antioxidants and zinc. In addition, eating a balanced diet with lots of fruits and vegetables and fish high in omega3 can also be beneficial in slowing down the advancement of the disease. Usually one eye is more affected in the dry form so patients may be able to lead a near-normal life by following certain lifestyle changes.
A healthy lifestyle of eating a balanced diet, regular exercise, no smoking, keeping a check on your weight and blood pressure, proper and regular eye examinations can help in preventing this disabling disease.
To help manage your visual loss, ask your eye care professional for available low vision devices such as magnifiers, high-powered reading glasses, talking watches and calculators that may assist with everyday tasks.
As AMD affects all aspects of day to day living, those with AMD may also develop lowered self-esteem or depression and require constant support of their family and friends to cope up with their visual disability. For more information on AMD, visit the Macular Disease Foundation Australia
Article written by Jen-Ni Quante - General Manager, eContactLenses