Age Related Macular degeneration, sometimes referred to as macular degeneration, is a chronic eye disease that affects the macula and causes diminished central vision. The macula is the central part of the retina which is responsible for visual acuity. It allows us to read and write, work on a computer or smartphone, recognize colours and faces, drive and view objects in fine detail. Researchers estimate that ARMD is responsible for about 5% of the global burden of blindness.
One can consider the eye to work like a camera wherein the light is focussed on the macula (the film). In normal circumstances, the light falling on the macula is collected in the form of images which are then sent to the brain for processing via the optic nerve. When the macula is damaged due to ARMD these images are not perceived properly.
Macular Degeneration Symptoms
ARMD usually produces a slowly progressive painless decrease in vision. Early signs of vision loss from ARMD include shadowy areas in the central vision with a characteristic waviness or fuzziness of the straight lines. As the condition progresses the decrease in visual acuity also increases leading to the presence of a dark black spot in the central visual field with the maintenance of peripheral vision. This can be likened to viewing a clock, wherein you are able to make out the numbers but not the hands of the clock.
Macular Degeneration Causes
Macular degeneration is generally associated with the normal ageing process. However, some risk includes:
- Having a cardiovascular disease, and
- Family history of macular degeneration
Macular Degeneration – Types
There are two basic types of age-related macular degeneration, the Dry form, and the Wet form. The majority of the cases belong to the Dry form of the disease, also referred to as the atrophic form. Wet ARMD or Exudative ARMD although less common leads to a more profound decrease in vision, wherein bleeding or edema is noted in the macula.
Macular Degeneration Diagnosis
The majority of macular degeneration cases are diagnosed during a routine eye examination. The initial test includes visual acuity tests and examination of the retina. The retinal specialist will conduct a dilated eye examination to notice edema or bleeding in the macula. Other tests include:
- OCT Angiography: It is a non-invasive test to pick up the bleeding or leaking vessels in the macula which are responsible for Wet ARMD.
- Fundus fluorescein angiography (FFA): It helps to identify the extent and pattern of leaking new choroidal vessels. Photographs of the retina are taken for 8-10 following an injection of a dye in the arm.
- Optical coherence tomography (OCT): This test offers a detailed cross-sectional retinal image.
Macular Degeneration Treatment
At the outset, there is no cure for ARMD. Depending on the type of the disease and extent of macular damage, your eye doctor may advise for medical management of surgical intervention.
In cases of Dry ARMD, the progression of the disease can be slowed by the use of specific multi-vitamins in the form of tablets. However, Wet ARMD does not respond to medical therapy and needs surgical intervention which may be in the form of intravitreal injections or laser therapy. When the injections are administered in the eye regularly, the drug can stop the growth of abnormal blood and leaking or bleeding under the retina. Another common treatment is Photodynamic therapy. In this procedure, a drug is injected into the patient’s arm. It then travels throughout the body and the new eye blood vessels. The drug sticks to the new blood vessels surface where it is activated by light of a specific wavelength. The new fragile blood vessels get destroyed as a result of drug activation.
Macular Degeneration After Effects
The main aim of intravitreal injections is to stabilize vision and to provide some improvement in visual acuity. The injections would be repeated at intervals so as to maintain the beneficial effect of the drug. Intravitreal injections of Anti-VEGF agents are the only treatment noted in clinical trials which provides a significant improvement in visual acuity.
Macular Degeneration Risks
Every treatment involves risks. The laser can further damage the macula. It may result in some blind spots or loss of vision. This risk is more likely when the leaking blood vessel is very near to or in the centre of the macula. The administration of intravitreal injections bears a risk of infection in the eye, the risk of which has been found to be extremely low.
Macular Degeneration Recovery
The benefit of macular degeneration surgery is that the procedure slows down the loss of the central vision. The recovery time is just a few weeks or months. However, the leaky abnormal blood vessels may appear back wherein retreatment may be needed.
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