Age-related macular degeneration, often called AMD or ARMD is the degeneration of the macula, which is the part of the retina responsible for the sharp, central vision needed to read or drive. Because the macula is affected in AMD, central vision loss may occur. Macular degeneration is diagnosed as either dry or wet.
Dry Macular Degeneration (non-neovascular) is an early stage of the disease and may result from the aging and thinning of macular tissues, depositing of pigment in the macula or a combination of the two processes. Dry macular degeneration is diagnosed when yellowish spots known as drusen begin to accumulate in and around the macula. Gradual central vision loss may occur with dry macular degeneration but usually is not nearly as severe as wet AMD symptoms.
click to watch animation (Dry macular degeneration)
Wet Macular Degeneration (neovascular). Dry AMD may progresses to the more advanced and damaging form of the eye disease. The wet form of ARMD is where new blood vessels grow beneath the retina and leak blood and fluid. This leakage causes permanent damage to light-sensitive retinal cells, which die off and create blind spots in central vision. Both dry and wet AMD cause no pain.
For dry AMD the most common early sign is blurred vision. As fewer cells in the macula are able to function, people will see details less clearly in front of them, such as faces or words in a book. Often this blurred vision will go away in brighter light. If the loss of these light-sensing cells becomes great, people may see a small--but growing--blind spot in the middle of their field of vision.
For wet AMD the classic early symptom is that straight lines appear crooked. This results when fluid from the leaking blood vessels gathers and lifts the macula, distorting vision. A small blind spot may also appear in wet AMD, resulting in loss of one's central vision. Slowing dry AMD's progression from the intermediate stage to the advanced stage will save vision from progressively worsening. The management involves taking specific high-dose formulation of antioxidants and zinc significantly to reduce the risk of advanced AMD and its associated vision loss. Wet AMD can be treated with laser surgery and injections (ie. Lucentis or Eylea) into the eye. None of these treatments are a cure for wet AMD. The disease and loss of vision may progress despite treatment.
Although there are no drugs to restore vision lost to macular degeneration, there are some available that help prevent vision form getting worse or even improve the remaining vision. One of the latest advancements in treatment of macular degeneration is Lucentis / Eylea. This drug targets the VEGF (vascular endothelial growth factor) protein, which is responsible for later stages of MD("wet") by promoting growth of abnormal vessels in the retina. Lucentis/Eylea blocks this VEGF, which results in the reduction of abnormal vessels in the retina. Lucentis blocks VEGF, which results in the reduction of leaking and swelling in the retina.
Lucentis is administered through an injection into the eye. It is a procedure that can be performed in the clinic, which is done under a local anesthetic.
Avastin is a monoclonal antibody that was developed for use in the treatment of certain cancers. Like Lucentis, it blocks the transmitter called VEGF, which is involved in growth and development of blood vessels. In the eye, Avastin has been found to be useful in treating certain conditions where VEGF is thought to be involved. These conditions often involve leaking or bleeding blood vessels. Examples of such conditions include age-related macular degeneration, diabetic retinopathy, occluded retinal blood vessels, macular oedema. By blocking the action of VEGF, leakage and swelling in the retina can be reduced and even shut down.
Avastin is also given via an injection into the eye. It is a dry procedure, which is done under a local anesthetic.
Triamcinolone is a steroid, which is usually given via an injection into the eye. It is done under local anesthetic, and as a day procedure. After the injection, an antibiotic drop is used in the eye for a week. Triamcinolone injections are used to treat macular oedema (swelling of the macula). The cause of the macular oedema may be related to macular degeneration, diabetic eye disease or post operative inflammation. The steroid acts to reduce the amount of accumulated fluid thus settling the inflammation. Immediately after the injection you will most likely notice a "black blob" in your vision. This is the triamcinolone suspended in the vitreous gel of the eye. Within two weeks the steroid will break up, and you may notice smaller "blobs" floating through your vision.
The main risks of injections into your eye include bleeding, infection and retinal detachment. Overall the risks are low, and probably less than 1 in 1000. Some patients experience a rise in eye pressure following the triamcinolone injection. This can usually be treated with drops medications to lower the pressure.