macular degeneration

macular degeneration Deterioration of the macula lutea, a common progressive disorder that causes partial or total loss of macular vision, causing difficulty in doing tasks that require fine frontal vision (such as reading and driving a car). Although some forms of macular degeneration affect young people, most macular degeneration occurs in people over 60 years of age and is termed age-related macular degeneration (AMD). There are two types of AMD: the dry type and the less frequent wet type. In dry AMD, loss of central vision occurs slowly due to the gradual breakdown of cells in the macula. Dry AMD may progress to wet AMD, which is sometimes referred to as advanced AMD. Neither type causes pain. An early symptom of wet AMD is that straight lines appear wavy. This happens because the newly formed blood vessels leak fluid under the macula. The fluid raises the macula from its normal place at the back of the eye and distorts vision. Another sign that a person may have wet AMD is rapid loss of central vision. In both dry and wet AMD, the person may also notice blind spots. A person who has any of these changes in vision should consult an ophthalmologist without delay. See also macular vision.