When a layer of support cells die light sensitive cells in the macula are not able to function normally. Age related macular degeneration induced damage can significantly affect the retina’s ability to convert light into neural signals that trigger visual recognition and images. Beneath the retina yellow drusen deposit form causing blurred vision and distortion, which will increase in size and number with time that cause blood vessels to grow beneath the retina which leak blood damaging it. Peripheral vision may not be affected, ability to see directly ahead becomes lost late into age related macular degeneration.
Exact causes of age related macular degeneration are not known. There are links suggesting that being overweight, high blood pressure, and smoking increase risks of development. Family history can also be a factor, as close to 20 genes have been identified which can contribute to the risk of developing age related macular degeneration. Age related macular degeneration has been shown by studies to be more common amongst Caucasian populations. Maintaining a healthy balanced diet and regular physical activity are recommended to reduce the risks.
Symptoms do not usually present in early and intermediate stages. There are two forms of age related macular degeneration: wet neovascular age related macular degeneration, and dry atrophy age related macular degeneration. Wet progresses rapidly over a few weeks to months. Dry progresses more slowly over a number of years. It is possible to have both forms in one eye, and each type can appear in any order. Symptoms include: visual hallucinations, blurred or distorted vision, colours not being as vivid, inability to see anything in the center of vision, and straight lines appear as wavy.
Age related macular degeneration has three stages and can progress at different rates in each eye. Early AMD is diagnosed by appearance of medium sized drusen, typically vision loss is not reported. Intermediate age related macular degeneration is diagnosed by large drusen, and pigment changes in the retina may occur, vision loss may occur but not always. Late age related macular degeneration vision loss occurs due ti damage to the macula.
Detailed eye examinations can detect age related macular degeneration. By using eyes drops to dilate the pupils to provide clear view of the back of the eye, using magnifying lens to inspect the optic nerve and retina. A visual acuity test is conducted to measure ability to see distances. Amsler grid graph paper is used to identify vision distortion of straight lines. Fluorescein angiography records blood flow in the retina, dye injected intravenously passes through blood vessels in the retina to help identify abnormal blood vessels or damage. Optical coherence tomography is used to capture detailed images of cross sections of the retina measuring thickness of each layer of the retina.
Wet age related macular degeneration is treated with injections into the eye to control blood vessels in the retina. Photodynamic therapy is used occasionally to prevent further deterioration.
Dry age related macular degeneration is sometimes treated with supplements to slow progression. Vision aids such as magnifying glasses are suggested to reduce effects.
Home environmental changes must also be made such as brighter lights, and training techniques designed to show patients how to make the most out of remaining vision.
Age related macular degeneration does not always cause total blindness, but it does significantly hinder the ability to carry out everyday activities such as reading and writing, driving, working, and recognizing faces, anything requiring ability to see small details may also be impaired.
