Good vision is essential to our quality of life.
We need it for nearly everything we do. When vision deteriorates, this could be a major source of anxiety.
Understanding the how’s and why’s of a particular condition are therefore important. One of the main causes of poor vision in people over 65 is , ‘Age-related macular degeneration’. To understand how this condition can affect your vision, it is important to understand how the eye works.
Light rays penetrate the eye through the cornea, pupil and lens. These light rays are projected onto the retina, a light-sensitive tissue at the back of our eye.
The retina consists of two parts: the peripheral part, and the central part. The central part houses the most sensitive area of the retina, called the “yellow spot” or “macula”. The peripheral part of the retina is much larger than the central part. The yellow spot or macula is responsible for central sharp detail vision, which we need to drive a car, to recognise people, and to read.
Macular degeneration is a common problem in patients from a certain age onwards. Although the real cause is still unknown, we learn more and more about it each day. We know for example that this condition occurs frequently within families, and less frequent in African patients. Some studies also show that smoking and high blood pressure may increase the risk of macular degeneration.
Researchers are also studying the benefits of nutritional supplements as part of the treatment and also use it to test new medical, surgical and laser treatments.
In general you could say that there is little we can do to cure this condition. But with early diagnosis, we may retain central vision. Therefore it is of utmost importance to go to your ophthalmologist for a routine check up on a regular basis.
A good understanding of the disorder is essential, an accurate monitoring of your sight with the Amslerchart also. Despite macular degeneration your quality of life can often still be preserved.
There are two types of age-related macular degeneration:
The retina consists of several layers that are very close to each other. Due to this close collaboration we are able to see properly
In patients with the dry form of age-related macular degeneration, cellular debris called “drusen” accumulates between the retina and the choroid, and the retina can become detached. Therefore, the quality of vision declines.
Many patients do not even realize that there is a problem until their central vision gradually diminishes, or until we discover a problem during a routine eye check.
This is an Amsler chart. It’s a simple test that you can use to detect changes in your central vision as soon as possible. How to use this text at home? Place yourself in a well lit area and keep the amsler chart at a comfortable distance. If you need reading glasses, feel free to wear them. Cover one eye, and look at the point in the middle of the grid. As you are looking at this point, ask yourself if the horizontal and vertical lines around this point run smoothly. If you perceive a squiggly line, or if you see spots or dark areas, this may mean that something is wrong. So, please contact your ophthalmologist immediately. Afterwards the test should be repeated with the other eye.
Many people develop age-related macular degeneration as they age. In most cases the disease only affects vision mildly. At this stage, no treatment is needed. However regular checkups using the amsler chart are required, in order to mark any commencing degradation. If changes occur in the amsler chart, this can be a tell tale sign that it may be evolving in to the wet or exudative form of age-related macular degeneration. Early diagnosis of this type is extremely important.
Age-related macular degeneration begins with characteristic yellow deposits (drusen) in the macula. Fluid leaks through the walls of these blood vessels, causing central vision to be affected even more. 10% of patients with age-related maculopathy develop the wet form.
Probably the most important factor in the treatment of this form is early detection. We must stress the importance of using the amsler chart regularly to discover this form as soon as possible. Once we suspect a problem, we use a diagnostic technique called fluorescein angiography and OCT-scanning in order to discover what is going on between the different layers of the retina.
In fluorescein angiography a coloured dye is injected into a vein of the arm. This dye passes to the blood vessels of the eye. The coloured blood vessels are then photographed with a special digital camera. These images can give us some idea of what is going on. This allows us to plot a treatment plan.
For some of the patients with the wet form of age-related maculopathy, treatment is possible. It is not a cure, but it can often slow down the growth of blood vessels. If this stage is not detected and treated early, it will often lead to severe impairment of the central vision.
If the abnormal blood vessels are not located right under the macula, we can attempt to treat them with the standard argon laser. Although it is very important to treat these blood vessels as quickly as possible, this treatment sometimes causes additional loss of vision.
When treating the wet form of age-related maculopathy, it is important to understand that an improvement of vision in many cases will no longer be possible. However, we can try to save the vision that is left.
Half of the patients who undergo treatment for the wet form of age-related maculopathy will re-need treatment within 3 to 5 years.
Intravitreal injections
For some time the “American Academy of Ophthalmology”, (see ref.) intravitreal (the vitreous, gel-like portion at the back of the eye), has been recommending intravitreal injections to treat conditions similar to the condition that you may have – like – new blood vessel formation in the vitreous fluid – oedema or fluid accumulation in the retina – age-related macular degeneration (ARMD) – retinal detachment, retinal abnormalities due to diabetes and other similar conditions.
This new treatment provides spectacular results in a significant number of cases for which no treatment was possible. Sometimes this treatment needs to be repeated after one or several months.
Various products – are used such as : Bevacizumab (Avastin) – Ranibizumab (Lucentis) – Pegaptanil (Macugen) – Kenacort. The injection of Avastin (the most active product) is off label, i.e. it does fall within the indication of this product. However if there are no alternatives (if there is no other treatment), it is proven that the condition you suffer from, can be treated by it, although it is not reimbursed by health insurance.
The risks of such an intravitreal injection are limited, but present – intraocular infection (1/2.000) – cataract (1/1.000) – general side effects (thrombo-embolic conditions) – intraocular pressure rise (rare and usually transient) – retinal detachment and vitreous haemorrhage (very rare). All of these potential complications can be treated if the need arises.
How does an intravitreal injection work?
The maximum stay will be two hours: preparation, treatment, and follow-up after one hour. The injection itself only takes a few seconds and is not painful, you may feel just a little sting.
Afterwards, you may experience seeing floaters for one to three days. For 3 days after treatment you should use Trafoxal (antibiotic drops) 3x/day. A few weeks after the treatment, you will receive a check up, and an OCT scan will be performed to evaluate the effect.
In this text we discussed the most common forms of age-related maculopathy. There are several factors that may be applicable for each individual patient. Understanding what is happening to your vision can help you adapt to this new situation.
If you have any additional queries about this condition, do not hesitate to ask any questions during the consultation.
