Age Related Macular Degeneration The Facts
What is age related macular degeneration (ARMD) ?
ARMD is degeneration of the most sensitive part of the retina (sensory part of the eye) called macula. It is mostly seen in people over the age of 50 years. It is of two types the dry type and the wet type.
Dry type of ARMD is the more common type and leads to a slow atrophy of the macula.
Wet type of ARMD is the less common form and leads to formation of abnormal blood vessels and haemorrhage beneath the macula.
Can it lead to blindness ?
The dry form which is the more common variety generally does not lead to blindness, but can lead to a decrease in vision.
The wet form which is the less common variety can lead to a marked fall in vision and blindness. The loss of vision occurs because of damage to the most sensitive part (macula) of the retina by blood and exudation.
What are its symptoms ?
Early symptoms are metamorphopsia, i.e. straight lines appear to be wavy and appearance of a black patch infront of the eye. The patient says that he/she can perceive well around the patch but cannot see within the dark circle. There also might be a sudden painless loss of vision.
Can it be treated ?
The diagnosis in most cases can be established by clinical examination alone. For patients suffering from the dry type of disease only use of antioxidant medicines is recommended. There is no LASER or curative therapy for this form of disease at present.
In patients with the wet form of the disease early intervention is necessary to prevent loss of vision. The present day treatment modalities mainly aim at destruction of the abnormal subretinal new vessels by different forms of LASERs. Depending on the location of these vessels a different LASER has to be used. However, the aim of any kind of therapy is to prevent further deterioration of vision. Lost vision cannot be restored in most cases.
For lesions slightly distant from the center of the macula conventional green LASER can be done. This generally leads to complete destruction of the vessels. Recurrence can occur in some cases.
For lesions that are directly under the center of macula either a Trans-pupillary Thermotherapy (TTT) or a Photodynamic treatment (PDT) has to be done.
TTT This involves treating the vessels with a long duration low energy LASER which aims only to destroy the blood vessels and not the retina. It has been shown in various studies to prevent further loss of vision but not hundred percent effective. Upto 3 sessions of the LASER treatment may be required.
PDT This involves treating the vessels with a LASER after injecting a dye which selectively enhances LASER energy absorption by the new vessels only thus preventing damage to the overlying retina. The dye which is injected is imported and at present very costly. This therapy also may be required to be repeated upto 3 times or more. International studies using this dye have found it to prevent further loss of vision in many cases but it is also not hundred percent effective.
What should I go for TTT or PDT ?
Both PDT and TTT aim at stabilization of vision and not improvement in vision. There are international studies claiming success i.e. stabilization of vision with both LASERS. The prohibitive cost of PDT makes it out of reach of many. TTT on the other hand is much cheaper. There are certain points like visual acuity type of lesion and size of lesion which can to an extent help take a decision regarding therapy suitable for a particular case. If you are in doubt, mail us your angiograms and OCT images if available and we shall help you decide.
How can I be helped at ARC Telediagnosis ?
We have a highly experienced retina specialist capable of performing all kinds of LASERS for ARMD. He can help you take a decision regarding the form of therapy you should opt for after seeing your investigations. We can also provide you information on new alternative treatment options now becoming available for the disease.