Macular Degeneration and Stem Cell Therapy
Macular degeneration is also referred to as age-related macular degeneration is the most common cause of permanent loss of vision in individuals over the age of 60. This condition leads to blurry or the entire loss of vision. Macular degeneration occurs when the macula of the eyes starts functioning less. The macula is the small middle part of the retina. The retina is the nerve-rich tissue, that can be found at the back of the neck. This condition is initially asymptomatic, however, some patients do have a progressive deterioration of their vision, which could either be in one, or in the two eyes. Even though this medical condition might not lead to total blindness, the loss of central vision could make it difficult to identify people, walk, drive cars, study, and other basic activities of life.
Macular degeneration occurs in adults, especially people above the age of 60. There are some factors that could play a role in the development of macular degeneration. Some of the factors include environmental and genetics. The damage to the retina macula is also a strong factor. This disease can be diagnosed by undergoing a full eye examination. In addition, this disease is classified according to a severity which is early, moderate or intermediate, and the late stage.
What Are the Signs and Symptoms of Age-Related Macular Degeneration?
Macular degeneration initially shows no symptoms, however, it starts presenting with symptoms as the disease progresses. Some of the symptoms of this disease are
- Reduction in visual acuity: Patients suffering from macular degeneration, usually experiences a sharp reduction in their visual acuity. As an illustration, their vision might drop from a 20/20 vision to a 20/80.
- Problem identifying colors: Macular degeneration patients generally have problems discerning between colors. For example, they might have problems differentiating between light tones, or light colors from the dark colors.
- Blurred vision: Macular degeneration can be divided into two. There are those that have exudative macular degeneration. This set of patients experience a rapid loss of vision. On the other hand, some patients have the non-exudative macular degeneration, which comes with a gradual loss of central vision.
- Difficulty in identifying straight lines: This condition presents like metamorphopsia. The patient sees straight lines as wavy, and might not even see some of the lines entirely. This becomes more evident when they try looking at poles that are arranged in a straight line, or just watching an army of more solid lined up in a straight line. They might also experience central scotoma, in which some areas of their vision is blank.
- Problems readjusting after exposure to bright light: Patient usually presents with difficulty adjusting after being exposed to bright light, such as the sun. This is one of the tests that could be used in diagnosing this condition. This test is called the photostress
- Lastly, patients might present with the loss of contrast sensitivity.
Age-related macular degeneration does not lead to total blindness, however, it’s capable of causing a lot of damage to vision. As a result of this, only a small number of people suffering from this disease eventually becomes totally blind.
What Are the Risk Factors of Macular Degeneration?
The risk factors of macular degeneration are the factors that predispose an individual to have this condition.
- Age: As the name implies, this disease occurs in people above the age of 60. So age is the most important risk factor for macular degeneration.
- History of the family: People who have a relative suffering from this medical condition have higher risks of having macular degeneration.
- Lifestyle: There are some activities and habits that increase the risk of having macular degeneration. Some of these are
- Smoking: Smoking cigarette, marijuana, and shisha increase the chances of having age-related macular degeneration by up to 2 or three times when compared to non-smokers. This is why it’s important to avoid smoking when you have a relative that has had this medical condition.
- Hyperlipidemia: This is the condition in which an individual has an excess amount of fat in the body. A high amount of fat and cholesterol in the body increases the risk of having age-related macular degeneration.
- Hypertension: According to studies, it has been observed that an elevated amount systolic and pulse pressure has a direct connection with late age-related macular degeneration. However, there is no strong evidence that an increased systolic and pulse pressure has a connection with the macular degeneration.
What Are the Types of Age-Related Macular Degeneration?
Age-related macular degeneration can be divided into two types. These are the dry and the wet form.
- Dry age-related macular degeneration: Dry age-related macular degeneration is characterized by blurred central vision. It might initially affect one eye but might affect both eyes as the disease progresses. This condition can lead to the loss of the ability to perform simple tasks, such as driving, cooking, reading and so on. There is the presence of drunsen in the macula. Drunsens are yellow deposits. A little quantity of these drunsens might not cause significant changes in the patient’s vision, however, they might reduce the patient’s vision as they get bigger in size. In severe cases of this condition, there might be atrophy of the macula, subsequently leading to the death of the macular
- Wet age-related macular degeneration: This form of macular degeneration is characterized by neovascularization. This is the growth of abnormal blood vessels from the choroid, beneath the macula. Blood leaks from the blood vessel into the retina, leading to the impairment of vision
How Is Macular Degeneration Currently Treated?
The dry form of macular degeneration has no treatment. On the other hand, the wet form of macular degeneration can be treated with medications. In addition to this laser, coagulation is also an effective treatment method.
Stem Cell Therapy of Macular Degeneration
Active research is currently ongoing on how to replace rods and cones. For example, induced pluripotent cells are used to grow rods and cones. These project when successful might be a good alternative for the replacement of the macula tissues. The stem cells are capable of regenerating and repairing the damaged tissues of the macula.
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Ratnapriya, R. and Chew, E. (2013). Age-related macular degeneration-clinical review and genetic update. Clinical Genetics, 84(2), pp.160-166.
Visionaware.org. (2018). The First Stem Cell Clinical Trial for Wet Macular Degeneration Is Underway in London – VisionAware Blog – VisionAware. [online] Available at: https://www.visionaware.org/blog/visionaware-blog/the-first-stem-cell-clinical-trial-for-wet-macular-degeneration-is-underway-in-london-2093/12 [Accessed 12 Jan. 2018].