What Is Macular Degeneration And How Is It Treated?

The macula is a photoreceptor-dense area at the back of the eye just superior to the optic nerve. Photoreceptors are specialized nerve cells that respond to light and relay signals to the brain. The brain interprets these signals as images. What is Macular Degeneration? Conditions involving this important structure disrupt central vision.

The most common diseases of the macula are age-related macular degeneration (AMD), juvenile macular dystrophies, myopic maculopathy, macular holes, diabetic macular edema, and retinal vein occlusion. Juvenile macular dystrophies are a collection of rare, inherited conditions that damage central, but not peripheral, vision. Most are diagnosed in childhood, although some are not discovered until later.

AMD typically affects elderly people. They experience either blurred central vision or no vision at all. There are two subtypes of AMD: dry and wet. The severity of AMD is broken down into early, intermediate, and late types. The late types are further subdivided into wet and dry forms. Nine in ten cases of late AMD are the dry form.

AMD can be prevented by following a healthy diet and by not smoking. There is no cure for the condition once it develops and lost visual capacity cannot be regained, although there are treatments that can slow its progression. These include photodynamic therapy, laser coagulation, and the injection of antibodies to a specific growth factor, VEGF, into the retina. Dietary supplements may also retard the development of the disease.

In photodynamic therapy, non-toxic light-sensitive compounds become toxic to certain cell types when they are exposed to light. Among these cell types are malignant cells and other diseased cells, such as damaged macular cells. This treatment can kill viruses, bacteria, and fungi and it has been used to relieve acne. In AMD, it is used to treat the wet form.

In laser coagulation, a beam of laser light is used to cauterize the ocular blood vessels. In addition to AMD, it is used to treat diabetic retinopathy, retinal ischemia, and glaucoma, among others. It is also used in non-ophthalmic procedures, such as urological and gastrointestinal surgery.

Anti-VEGF therapy blocks the activity of a growth factor, vascular endothelial growth factor. VEGF is a peptide, which means that it must be injected to avoid their digestion by acids in the stomach. There are small molecules that may be taken orally to block the activity of tyrosine kinases (enzymes), that are stimulated by the production of VEGF. Cannabidiol may also be used to inhibit VEGF. It is also used in some cancers, like brain tumors.

Age-related macular degeneration affects tens of millions of people all over the world. It is the fourth most common cause of blindness. Loss of central vision affects the ability to distinguish faces, read, drive or engage in other activities of daily life (ADL). It may also impair the ability to distinguish colors. It is most commonly diagnosed in people over the age of 50. The good news is that AMD cannot cause total blindness. Regular annual eye tests can detect the condition early so that disease-modifying treatment can begin.

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