Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia, Wikipedia.

macular degeneration

breakdown of cells in the macula lutea, resulting in a loss of central vision in the affected eye; peripheral vision is not affected. There are several varieties; most appear in persons 50 to 60 years of age (age-related macular degeneration), but one variety is congenital and is seen in younger people (stargardt's disease or Stargardt's macular degeneration). In about 75 per cent of cases the cause is not known, and nothing can be done to prevent, arrest, or reverse the process.
Patient Care. Since a large majority of cases of macular degeneration cannot be arrested or treated, care is aimed at making the most of the vision that the patient has. The condition does not progress to total blindness and usually is self-limiting. The inability to perceive detail can be compensated for in part by using large-type books and magazines and a magnifying lens for reading, and having adequate lighting whenever detail work is necessary.

Patients with macular degeneration are given a sheet of paper on which is printed a grid of horizontal and vertical lines. They are instructed to look at this grid daily and note whether there is any change in distortion of lines in the center of vision. This same technique can be used as a screening test to evaluate central vision. However, seeing distorted lines in the grid is not necessarily symptomatic of macular degeneration. Further examination by an ophthalmologist is necessary for a definitive diagnosis.
Grid for evaluating macular degeneration.
age-related macular degeneration (ARMD) a type having its onset between the ages of 50 and 60, the leading cause of blindness in persons over the age of 65. There are two main types, involutional and exudative age-related macular degeneration.

The involutional (dry or non-exudative) type accounts for 90 per cent of cases and is characterized by the gradual wearing out of the cells in the retinal pigment epithelium, resulting in a slow, progressive loss of central vision. Although visual acuity loss usually does not progress beyond the 20/200 level, this is a significant disability. Treatment is not generally available.

The exudative (neovascular or wet) type is characterized by the growth of a neovascular membrane within or very close to the macula, resulting in distorted and blurred vision. The vision loss from this type of macular degeneration may be only of hand movements. Laser photocoagulation of this form of macular degeneration is aimed at destroying the neovascular membrane; if diagnosed and treated very early when the membrane is small, significant loss of central vision may be avoided.
Patient Care. Health care providers can be of great help for early diagnosis of this devastating disease through ongoing patient education programs. After laser treatment, which is performed under a retrobulbar anesthetic, the patient should be instructed to leave the patch in place for at least six hours. Any increase in distortion or blurred vision should be immediately reported and followed up by an urgent outpatient exam. Low vision aids and services can improve quality of life for persons with this disorder.
Stargardt's macular degeneration Stargardt's disease.


Age-related macular degeneration, see there.

Age-related macular degeneration (ARMD)

Degeneration of the macula (the central part of the retina where the rods and cones are most dense) that leads to loss of central vision in people over 60.
Mentioned in: Cataract Surgery
References in periodicals archive ?
For the first, we included variables for age, time before initial diagnosis, number of periods since initial diagnosis of DM (for diabetic retinopathy) or ARMD, and ocular comorbidities.
For ocular comorbidities, we defined binary variables using the ICD-9-CM diagnosis codes in Table 1 for DM, background diabetic retinopathy (BDR), proliferative DR (PDR), and unspecified DR (UDR); suspected glaucoma, primary open-angle glaucoma (POAG), narrow-angle glaucoma (NAG), and other glaucoma; dry ARMD, wet ARMD, and unspecified ARMD; and cataract.
However, since treatments for DR were much more effective on average for DM than for ARMD during the observational period, this difference should be reflected in differences between the two conditions in the propensity to be examined.
What he and other doctors do know is that smoking, high blood pressure, poor diet and over-exposure to sunlight increase the risk of getting ARMD.
It can affect anyone, regardless of age, sex or nationality, but because it most often strikes people 60 and older, it is commonly referred to as "age-related macular degeneration" or ARMD.
ARMD sneaks up on its victims, robbing them of precious vision a fraction at a time.
High blood pressure and high cholesterol levels predispose you to ARMD, so have annual checks of both.
Wet ARMD requires urgent treatment because about two-thirds of people will have severe loss of vision within two years.
ARMD is the leading cause of blindness among older Americans.
The wet form of ARMD can often be successfully treated with laser therapy, if treatment is initiated when symptoms are first noticed.
He recommends, however, that people seek their optometrist's advice about using lutein to help prevent ARMD.