Macular Degeneration
Macular degeneration, often called AMD or age-related macular degeneration, is a disease that destroys the sharp, central vision needed to see objects. The retina becomes severely damaged, but causes no pain. AMD affects the macula, the part of the eye that allows you to see fine detail and most sensitive part of the retina, by causing cells in the macula to die.
There are two types of macular degeneration: wet and dry. Wet AMD, which occurs when abnormal blood vessels grow under the macula, damages the macula quickly and causes blurred vision, an early symptom. The new blood vessels are fragile and leak blood and fluid, causing the macula to swell and damages and scares the retina. Objects also don't appear to be as bright, causing people to have trouble recognizing faces and reading. It is considered to be more severe because of the rapid damage it can cause. Straight lines appear to be wavy, and a blind spot usually develops, resulting in the loss of central vision.
Treatment for wet AMD include injections, photodynamic therapy, and laser surgery. Injections of vasular endothelial growth factor (VEGF) slow the progression of wet AMD by promoting the growth of new abnormal blood vessels. Then, the anti-VEGF injection blocks its effects. Multiple injections are needed for the treatment to work. Photodynamic therapy uses a laser to activate verteporfin, which is injected at the beginning of treatment. Once the drug is activated, it destroys the new blood vessels and slows the rate of vision loss. Laser surgery, a less common treatment, uses a laser to aim an intense beam of light at new blood vessels in the eyes to destroy them, but can also destroy surrounding healthy tissue and cause more blurred vision.
Dry AMD occurs when light-sensitive cells in the macula slowly break down, causing you to gradually lose your central vision. A common early symptom is that straight lines appear to be curved or crooked. It has three stages: early, intermediate, and advanced. Drusen, yellow deposits under the retina, are also early signs of dry AMD. However, drusen do not cause vision loss, but instead cause people who have large deposits of them to be more at risk to a severe form of AMD. Early AMD have small or few medium drusens and symptoms and vision loss has not occurred yet. Intermediate AMD have medium to large sized drusen, but still have no symptoms. However, some see blurred spots in the center of their vision and may require more light to read and do other tasks than normal. Advanced dry AMD have drusen and a breakdown of light-sensitive cells that support the tissue in the macula. The breakdown causes blurred spots in the center of a person's vision, called geographic atrophy. Over time, the spots grow, getting lager and darker until it takes away a large area of a person's central vision.
Treatment for wet AMD include injections, photodynamic therapy, and laser surgery. Injections of vasular endothelial growth factor (VEGF) slow the progression of wet AMD by promoting the growth of new abnormal blood vessels. Then, the anti-VEGF injection blocks its effects. Multiple injections are needed for the treatment to work. Photodynamic therapy uses a laser to activate verteporfin, which is injected at the beginning of treatment. Once the drug is activated, it destroys the new blood vessels and slows the rate of vision loss. Laser surgery, a less common treatment, uses a laser to aim an intense beam of light at new blood vessels in the eyes to destroy them, but can also destroy surrounding healthy tissue and cause more blurred vision.
Dry AMD occurs when light-sensitive cells in the macula slowly break down, causing you to gradually lose your central vision. A common early symptom is that straight lines appear to be curved or crooked. It has three stages: early, intermediate, and advanced. Drusen, yellow deposits under the retina, are also early signs of dry AMD. However, drusen do not cause vision loss, but instead cause people who have large deposits of them to be more at risk to a severe form of AMD. Early AMD have small or few medium drusens and symptoms and vision loss has not occurred yet. Intermediate AMD have medium to large sized drusen, but still have no symptoms. However, some see blurred spots in the center of their vision and may require more light to read and do other tasks than normal. Advanced dry AMD have drusen and a breakdown of light-sensitive cells that support the tissue in the macula. The breakdown causes blurred spots in the center of a person's vision, called geographic atrophy. Over time, the spots grow, getting lager and darker until it takes away a large area of a person's central vision.
Amsler grid
The Amsler grid was used since 1945, and is a grid of horizontal and vertical lines that are used to monitor a person's central visual field. It was developed by Marc Amsler, a Swiss ophthalmologist. To use it, a person looks at the the dot with each eye separately.