Macular degeneration is a disease of the eye that causes destruction of the central vision. This vision is responsible for making things visible clearly and helps one carry out daily tasks like driving or reading.
Macular degeneration is a silent disease, that is, painless. It progresses gradually, such that the person affected never notices the failing vision. In some cases, the degeneration happens so fast that one suffers from loss of vision in both eyes. It affects the macula and is of two types, wet and dry.
What is the Macula?
The macula is a part of the retina. It is present at the back of the eye and is as small as a grain. It contains most of the photoreceptor cells that helps see the light. These cells send messages to the brain. This helps in interpretation of the object as an image. The macula is very important as it carries out some of the very important functions to facilitate the vision. These functions include:
- Responsible for central vision
- Ablility to see fine details of objects
- Most of the color vision
What is Macular Degeneration?
Age-related macular degeneration is a disease that is related to the normal wear and tear of an aging body. It leads to loss of vision and blindness in people over the age of 50. It makes it very difficult to read, recognize faces, drive, etc. However, the peripheral vision will allow the person to carry on with daily tasks.
What Happens in Macular Degeneration?
Age-related macular degeneration (ARMD or AMD) occurs as the person ages. One will observe yellow deposits (drusen) present in the macula. The person who develops dressing has a clear vision. Thus, one never notices the degeneration until they develop the advanced stage of macular degeneration.
Types of Macular Denegeration
There are two types of macular degeneration: wet and dry.
Dry Age-related Macular Degeneration
The gradual deterioration of the macula over the years leads to macular degeneration. The disease leads to thinning of the macular tissues. The drusen pigments too get deposited in and around the macula. These drusen pigments are thought to be the debris of the deteriorating tissues.
Slowly, the central vision is lost. This loss of vision is not as severe as the wet macular degeneration. There is no treatment available as of now for dry macular degeneration. Most of these treatments are conducted as clinical trials.
Wet Macular Degeneration
In case of wet macular degeneration, one observes the growth of new blood vessels under the retina. These blood vessels begin to leak blood and fluid, that causes permanent damage to light-sensitive photoreceptor cells. Thus, leading to blind spots in the central vision.
The new blood vessels grow due to choroidal neovascularization (CNV). This process is the body’s way to supply more oxygen and nutrients to the retina. However, the process leads to scarring and loss of central vision.
There are two types wet macular degeneration, occult and classic. In case of occult, the new blood vessels growing beneath the retina are not very specific. The leakage is thus not very evident and leads to less severe loss of vision. The classic condition where the blood vessel growth and scarring are clearly evident. This condition leads to severe vision loss.
Causes of Macular Degeneration
There are many factors that can lead to macular degeneration. However, the exact cause of macular degeneration is not yet known. Some of the factors that may contribute to the development of macular degeneration include:
- Age: The natural process of aging increases the risk of macular degeneration.
- Smoking: Smoking causes damage to the structure and blood vessels of the eye. Thus, increasing the risk of macular degenerating 3 times more in smokers than non-smokers.
- Blood pressure: High blood pressure increases the risk of developing age-related macular degeneration.
- Sunlight: Eyes are very sensitive to sunlight and UV rays. These rays from the sun can damage the eye cells leading to degeneration.
- Genetics: People who have a family history of degeneration are more likely to develop the same.
- Gender: It has been found women are more prone to macular degeneration than men.
- Diet: Poor diet lacking fresh fruits and vegetables increase the risk of AMD.
Symptoms of Macular Degeneration
The symptoms of macular degeneration do not appear in the early stages, especially when just one eye is affected. Some of the symptoms include:
- Blurry vision
- Gaps in vision
- Straight lines appear distorted or bent
- Problems adjusting from a dark environment to light
- Difficulty looking at the bright colors
- Disappearing words while reading
- Missing areas of vision
- Difficulty differentiating between dark colors from dark and light ones from light
An eye examination including fluorescein angiography helps in identification of the abnormal blood vessel growth. Other methods include an optical coherence tomography.
The dry macular degeneration has no treatment. In order to slow the vision loss, doctors recommend dietary changes. Include green leafy vegetables and low-fat foods in your diet. Some may also be prescribed nutritional supplements.
Wet macular degeneration can be treated with photocoagulation. This is a type of laser treatment. Here, Photodynamic therapy (PDT) is used. In this method, a medicated injection is given that is activated with help of laser shone into the eye. However, there is no permanent cure to prevent loss of central vision.
This was all about macular degeneration. This is a painless disease, thus, make sure you get your eyes tested regularly. Any changes can get noted on time and the doctor may suggest treatment that helps prevent loss of vision.
Written by: Saptakee sengupta
Date last updated: March 13, 2015