Age-related macular degeneration (AMD) is a deterioration or breakdown of the eye’s macula due to age or abnormal blood vessel growth. The macula is a small part of the eye located on the retina—the light-sensitive tissue lining the back of the eye. The macula is the responsible for your central vision, allowing you to see fine details clearly.
AMD destroys this central vision. If left untreated, it can cause blindness.
There are two forms of AMD, dry and wet. Dry AMD is the most common. The disease generally goes unnoticed until it is detected during an eye examination.
How is macular degeneration diagnosed?
Thorough eye exams, involving dilation of your pupil, and visual field tests are used to diagnose macular degeneration.
The earlier AMD is diagnosed, the better chance you have of preserving some or much of your central vision. That is why it is so important that you and your ophthalmologist monitor your vision in each eye carefully. Regular eye exams help diagnose macular degeneration early.
You can also monitor your central vision using the Amsler grid. Here’s how:
- Wear your reading glasses and hold the grid 12 to 15 inches away from your face in good light.
- Cover one eye.
- Look directly at the center dot with the uncovered eye and keep your eye focused on it.
- While looking directly at the center dot, note whether all lines of the grid are straight or if any areas are distorted, blurry or dark.
- Repeat this procedure with the other eye.
- If any area of the grid looks wavy, blurred or dark, contact your ophthalmologist immediately.
How is macular degeneration treated?
Laser Therapy: If a fluorescein angiogram shows that the abnormal blood vessels have not grown under the center of the macula, it may be possible to treat them with standard laser therapy. It is important to stop the spread of these vessels as quickly as possible, but depending on how close the vessels are to the center of the macula, the patient may experience some further permanent blurring or loss of vision after the procedure.
Photodynamic Therapy: If the abnormal blood vessels grow under the center of the macula, standard laser treatment would permanently damage the macula, worsening vision. In some of cases, Photodynamic therapy (PDT) may be an option. This therapeutic procedure uses a combination of a light-activated drug called a photosensitizer and special low-power or cool laser. The combination can be used to treat wet AMD right at the center of the macula. With PDT the photosensitive drug is injected into the patient and travels throughout all the blood vessels including the abnormal vessels behind the central macula. The drug attaches to molecules that are commonly found in rapidly growing cells such as those in wet AMD blood vessels. A low power laser light is focused directly on the abnormal vessels which activates the drug causing damage specifically to the unwanted blood vessels.