Age-related Macular Degeneration (AMD) is a retinal disorder that is a leading cause of legal blindness in people in the western world.
Although AMD cannot be cured, severe vision loss in certain forms of AMD can be prevented by early diagnosis and prompt intervention. AMD has a progressive irreversible loss of central visual function. About 60% of people with AMD are therefore legally blind in both eye’s by the age of 75 years.
AMD is characterized:
- Gradual decrease in area’s of central visual function
- Patients are unaware of the extent of the changes unless a full visual evaluation is performed on a regular basis.
There are various types of AMD that provide different sign’s and symptoms of visual dysfunction.
- Dry AMD: Patients wil notice a gradual loss of central vision which is more noticeable with near related tasks.
- Wet AMD: Patients will notice a profound and rapid loss in central vision due to an accumulation of fluid in the macula causing:
- Dysmorphopsia: development of mal-shaped structures caused by the accumulation of fluid in the macula resulting in distorted vision.
- Scotoma: Loss of sight at a specific area due to retinal cell loss, therefore becoming a”blind spot”.
- Blurred Vision. This therefore leads to severe visual impairment. Treatment can slow down the rate of progress of the disease but will not stop the disease nor reverse the damage caused by the disease.
Risk factors for AMD
Numerous factors are implicated in the progression and development of AMD.
- Age. Patients over the age of 65 have a higher incidence of developing AMD
- Gender. Females tend to have a higher incidence of AMD than males
- Race. There is a higher incidence in Caucasians than Africans and Asians
- Various Ocular factors
- Hereditary Factors
- Systemic Factors
- Environmental Factors
Early detection and prevention
Studies have shown that the effects of aging on the retina may result from oxidative stress to the RPE brought on by the depletion of antioxidant enzymes. The activity of these enzymes decreases with age or from the cumulative phototoxic effects of exposure to UV radiation and blue light and this leads to macular damage.