Age Related Macular Degeneration (Yellow Spot Disease)
Yellow Spot disease, like in Turkey, is one of the main diseases causing visual loss on the people over the age of 55-60 in the whole world. People with the yellow spot disease have problems in the daily tasks such as reading, driving, spotting faces, watching TV and so on. However, in the advanced stage of this disease people would not go into a state of complete amourosis; they continue to see, but with the visual field outside the visual center.
What Is Yellow Spot Disease ?
Retinal layer of the eye is the layer consisting nerves that realizes the coming light and sends it to the brain. If we consider the eye as similar to a photographic apparatus, retinal layer would be the film strip inside it. Macular region is located right on the middle of this layer, and in the very middle of this region, fovea region is located. Fovea region is in the size of a pinhead. Fovea region, or colloquialy, “yellow spot”, is the most important region responsible of the central and detailed vision of the retinal layer. In the Yellow Spot disease the individual has distortion and visual loss while looking at objects.
Yellow Spot (fovea) is the most important part providing visual function
No matter how the retinal layer contains vascular layers inside, it greatly feeds from the rich vessel layer located right under it.
There is a thin membrane between these two layers and it functions as a barrier filter. During the whole life, the waste materials accumulating by the toxic effect of light, is cleared from this region by a certain mechanism and they are transmitted to the rich layer through the underlying vessel and removed via blood.
In Yellow Spot disease, commonly on some people over the age of 50 – 55, the toxic material can not be removed for an unkown reason and trigger a series of unfavored events by accumulating in this region. This way the disease starts.
Yellow Spot disease has two categories: dry type and wet type. In the dry type due to the accumulating waste material cell loss emerges in a certain amount. In the wet type unfavored vessel sprouts emerge between the layers right under the yellow spot. Leakage and hemorrhage emerges in a very short time after the vessels sprout and visual loss starts. 90% of the Yellow Spot diseases are dry type, however the wet type is responsible of 90% of the visual losses. That means it causes visual loss even though it is more rare. A dry-type Yellow Spot disease could later turn into the wet type. That’s why frequent examination is required.
Dry type Yellow Spot disease Wet type Yellow Spot disease
What are the symptoms of Yellow Spot disease ?
When the disease turns into the wet type, the early symptoms show themselves as distorted vision, and a visual loss in straight lines.
In wet type Yellow Spot disease, Visual loss at the very center
visual loss emerges firstly in straight in wet type Yellow Spot disease
lines, then it effects the very center.
To determine the distortion while looking at straight lines, the patients are regularly given a simple, grill – type card to test. This card is called Amsler card. The patient (if using), should wear his/her reading glasses, look at the middle of the Amsler card by closing the eyes one by one, and test whether there is a distortion on the straight lines on the card. In wet type Yellow Spot disease the distortion on straight lines can be determined this way. If there is an unusual image, a retinal examination should take place without losing time.
Amsler Card Amsler Card test
Sample of distortion that could be perceived by the patient on Amsler card in wet type Yellow Spot disease.
Does the other eye get affected from Yellow Spot Disease ?
Yellow Spot disease affects both eyes. However it is common that the effect of disease is higher on one of the eyes than the other.
Is there any protective precaution ?
Although it is not completely possible to prevent the transformation from dry type to wet type, a series of changes in lifestyle and nutrition decrease the risk of progression of the disease through more advanced stages.
The role of smoking is proved to progress the disease. If the patient is a smoker, he/she should quit as immediate as possible. The studies is also proven that the green fibrous vegetable and fruit consumption slows down the process of the disease.
Along with that, these multicentral and wide studies about this disease proved that some antioxidant vitamins and mineral – containing drugs decrease the risk of the transformation from dry type to wet type, therefore the visual loss. The vitamins recommended in these studies are as follows:
Before takin the vitamin/mineral combinations it is of extreme importance to consult your ophthalmologist. He/she may have a group of additional recommendations (such as smokers should not use beta-carotene, vitamin E should not exceed 400 IU).
Risk Factors for Age Related Macular Degeneration (Yellow Spot Disease)
What should be done for the protection against Yellow Spot disease ?
How is Yellow Spot disease treated ?
When there is a transformation from dry type to red type in Yellow Spot disease, urgent treatment is required. Until recently the treatments applied in this disease were not satisfactory, however today with the technology and new treatment methods, a huge success is obtained.
The aim of treatment in wet type Yellow Spot disease is to dry the vascular sprouts, fluid leakages and hemorrhages between the layers causing the disease. Different options are available for this.
It is the earliest treatment method applied in yellow spot disease. The situations in which laser treatment can be made are limited today. Approximately 15% of the Yellow Spot disease patients are suitable for laser treatment. Vessel sprouts can reactivate in 50% of the patients who had laser treatment.
Photodynamic Treatment (PDT)
It is a treatment method developed after the standart laser treatment and used for approximately 10 years. In PDT, by injecting a substance called verteporfin (Visudyn) this medicine is connected to the damaged tissue in the eye. Then a specific laser treatment is applied to the eye for 83 seconds. It is effective in certain types of wet type yellow spot disease. It generally does not provide visual gain, and the rate of protection of the current vision is 50 – 60% during 1 year treatment. This rate decreases in the forthcoming years. Today it is used rarely, for only suitable cases. Besides that, it can be used by combining the new injected medicine mentioned below.
Anti – Vascular Endothelial Growth Factor Treatment
It is the most recent and most effective method of treatment for wet type Yellow Spot disease today. It consists of active ingredients such as Bevacizumab (Avastin, Altuzan), ranibizumab.
In wet type Yellow Spot disease, unfavored vessel sprouts emerge between the layers that form rear wall of the eye (see “What is Yellow Spot Disease”). During the formation of those vessel sprouts, the growth factors affecting that region take part. With anti – vascular endothelial growth Factor treatment, theese growth factors are disabled and the emerging vessel sprout is removed, leakage and hemorrhage is prevented. In this treatment the drugs such as bevacizumab (Avastin, Altuzan) are directly injected to the eye.
With this treatment for the Yellow Spot disease the rate of protection of the current vision is above 90% in one year period. In the same period the rate of visual gain is around 30%s. To prevent visual loss and obtain visual gain these injections are repeated frequently.
Anti – VEGF treatment in Yellow Spot Disease
What should be done in the tracking stage ?
Dry type or wet type, the Yellow Spot disease requires regular tracking. In the stage of diagnosis and in the tracking ophthalmic angio (FFA- fundusfluoresceinangiography) retinal tomography (OCT – opticcoherencetomography) should be made.
Ophthalmic Angio Scan Optical Coherence Tomography