AGE RELATED MACULAR DEGENERATION
If your eye were a camera, the front part of the eye is the lens of the camera and the back part of the eye is the film of the camera. The lens of the camera is similar to the lens in the eye. The lens develops cataracts. The film of the camera is similar to the retina. The center of the retina is called the macula and it does most of the detailed vision. The macula develops macular degeneration. Dry Macular degeneration is wear and tear to the retina like cracks in the sidewalk. Wet macular degeneration is when blood vessels grow up through the retina like weeds through the cracks in the sidewalk.
The inner layer of the eye is the retina, which contains nerves that communicate sight, and behind the retina is the choroid, which contains the blood supply to the retina. In the dry (non-exudative) form, cellular debris called drusen accumulate between the retina and the choroid, and the retina can become detached. In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid behind the retina, and the retina can also become detached. It can be treated with laser coagulation, and with injectable medication that stops and sometimes reverses the growth of blood vessels.
Age related macular degeneration is a condition usually of older adults which results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. At first it may be difficult to tell the difference between a 6 and an 8. It may make it difficult to read or see details. If it advances, it is a major cause of blindness in the elderly. Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.
Although some macular dystrophies affecting younger individuals are sometimes referred to as macular degeneration, the term generally refers to age-related macular degeneration (AMD or ARMD).
Age-related macular degeneration (AMD) is the most common cause of vision loss in individuals over the age of 50. The name of the condition derives from its cause: damage to the macula, the most sensitive spot on the retina, required for clarity in the center of the visual field. The macula transmits electrical signals through the optic nerve to the brain. Damage to the macula results in retinal tissue degeneration that gradually worsens, diminishing or destroying central vision.
The speed at which AMD advances is variable. In some patients, the condition progresses slowly and the changes in vision are imperceptible for some time. In others, the disease moves at an accelerated pace, leading relatively quickly to loss of central vision in one or both eyes. While AMD does not result in complete blindness because some peripheral vision always remains, it does make ordinary activities, particularly those that require close visual acuity, increasingly difficult.
Stages and Types of AMD
There are three stages of AMD. These stages are designated both by signs detected by the ophthalmologist and symptoms experienced by the patient.
Early Stage AMD
During early AMD, Dr. Perozek can diagnose the illness by the presence of more than the usual number of drusen, yellow deposits under the retina, These drusen of medium size. Typically, patients with early AMD are not yet experiencing any loss of vision.
Intermediate Stage AMD
When a patient is in the intermediate stage of AMD, Dr. Perozek observes large drusen as well as possible changes in retinal pigment. While some patients at this stage may experience small gaps in vision, most patients with intermediate AMD do not experience any significant vision loss.
Late Stage AMD
During late stage AMD, patients have enough damage to the macula to experience significant vision loss. The two types of late AMD are:
- Dry, or geographic, in which macula tissue degenerates
- Wet, or neovascular, in which abnormal blood vessels grow
In the wet type of AMD, which progresses more rapidly than the dry, the newly developed blood vessels may leak blood and fluid. Visual loss in dry AMD usually occurs more gradually. Ninety percent of patients diagnosed with AMD have the dry variety, but approximately 10 percent of these patients later develop the wet variety of the disorder. Although patients with either type may experience vision loss, wet AMD not only progresses more rapidly, but usually results in greater visual damage.
Risk Factors for AMD
Individuals over the age of 50 with a family history of the disease are at increased risk of developing AMD. Environmental factors may also increase risk. These include:
- Poor diet
- Lack of exercise
- Excessive exposure to sunlight
- Elevated blood pressure
- Elevated cholesterol levels
Females and people with light skin or eyes are at greater risk of developing this condition.
Symptoms of AMD
Just as there are a number of signs that indicate the presence of AMD to the ophthalmologist, there are a number of symptoms experienced by the patient. Visual symptoms of macular degeneration may include:
- Wavy lines
- Gradual lessening of color perception
- Distorted or blurry vision
- Dimmed vision, especially when reading
- Dark spots in the center of the visual field
In a great many cases of AMD, even when the central field of vision has been lost, patients retain enough visual acuity to navigate their daily lives.
Diagnosis of AMD
In order to definitively diagnose AMD, any or all of the following are necessary:
- Visual acuity test
- Physical examination of the back of the eye after dilation
- Amsler grid test for central vision
- Fluorescein angiogram, in which dye highlights the blood vessels
- Optical coherence tomography (OCT/HRT)
During the physical examination of the eye, Dr. Perozek takes particular care to look for pigment changes under the retina, as well as for drusen.
TREATMENT OF AMD
While there is not yet a cure for AMD, many patients have been helped greatly by recent innovations in treatment. Regular eye examinations with SEE RIGHT NOW with TIMOTHY PEROZEK, MD to facilitate early detection of AMD are essential, since most therapies work best when started at an early stage of either type of the disorder. Even though treatments cannot reverse the disease process, they are often able to stop the progression of symptoms so the patient can maintain as much vision as possible.
Recommended treatments for AMD may include one or more of the following, each of which approaches controlling AMD in a somewhat different way:
Vitamin and mineral supplementation known as AREDS II
Amsler Grid monitoring
Injections of anti-VEGF (vascular endothelial growth factor)
Laser submacular surgery
Use of low vision aids
Be sure to call Dr. Perozek at 702-982-1360 to make an appointment to determine if you have any signs of Macular Degeneration.