Macular Degeneration – 2

Causes
Macular degeneration in young age – Although this condition rarely shows up in younger people, but when it does the most common cause is by inherited genetic disorder. These disorders include –
Best’s disease which is a progressive type
Stargardt’s disease affects macula
Sorsby’s dystrophy which occurs around 30-40 years of age and causes partial vision loss.
Dry age-related macular degeneration (AMD) –
With old-age, the retinal pigment epithelium (RPE), the layer which surround the retina, begins to break-down and becoming thin. This layer provides nutrition to the retina and clears it waste, so when it breaks down, it does not perform its exchange functions effectively. The waste products begin to get collected in the retina in the form of small deposits called drusens. The coupled effect of lack of nutrition and building up of drusens, damages the light cells of the macula, making central vision hazy and less defined.
Wet age-related macular degeneration (AMD) –
The wet AMD has the same initial process of break down of RPE, but it also has small new blood vessels growing under the macula, which can leak blood or fluid. This causes serious complications like blind spots and visual distortion. It is sometimes understood that the cause of these new blood vessels to come up is to get rid of the waste products collected due to RPE damage, however, there is no certainty to this thought.
Risk factors – There are certain risk factors which cause the condition:
Age – risks increase with age, most affected people are over 50 years.
Gender – women are at greater risk than men.
Genetics – inherited faulty gene may play a role, however, the specifics of this gene are not clear yet.
Smoking
Sunlight – excessive exposure to bright sunlight increases risk.
Diagnosis
If you experience symptoms of macular degeneration, you must see your GP, and if the GP also suspects the same, you will be referred to an ophthalmologist.
He will do a routine eye check-up and some tests to confirm the diagnosis. A magnifying glass is used to check the retina and macula at the back of your eye to identify any abnormalities. The tests include:
Amsler grid – this is the initial test done to diagnose macular degeneration. The person is asked to look at a special grid of vertical and horizontal lines, called Amsler grid. A person having macular degeneration will find some of the lines faded or distorted or broken, especially the lines nearest to the center. The eye specialist can gauge the extent of macula damage by seeing which lines are found to be distorted or broken.
Fluorescein angiography – this test confirms the type of AMD – dry or wet – that the person suffers from. A special dye is injected into the arm and the retina and macula of the eye are observed for any dye leakages using magnifying glass and special camera images. If the dye is found leaking from the blood vessels behind the macula, the person has wet AMD.
Coherence tomography – this technique uses special rays of light to scan the retina and produce image of it, indicating any abnormalities around the retina or thickening of macula.