What is macular degeneration?
Macular degeneration is an eye disease that causes the loss of central vision but rarely results in total blindness. Aging individuals and the elderly are adversely affected and at a greater risk of developing age-related macular degeneration (AMD). Two types of macular degeneration can occur – wet or dry.
Dry macular degeneration is more common and accounts for approximately 80% of AMD cases, according to the American Academy of Ophthalmology. Wet macular degeneration, while less common, is acute, with symptoms and complications occurring suddenly and needing immediate attention. Both are difficult to contend with as vision loss drastically complicates daily life, however, prevention and early detection can help.
Similarities and Differences between Wet and Dry Macular Degeneration.
Both types of AMD share some symptoms, signs, and complications while also having key differences. They each are spurred by the same risk factors:
- Family history
- Lifestyle factors including smoking, obesity, and diet
- High cholesterol
- Race – caucasians are more likely to experience AMD
- Prolonged exposure to extremely sunlight
- High blood pressure
Dry age-related macular degeneration
Part of the retina, the macular is a 5mm component that is responsible for processing light, color, and the fine detail that our central vision provides. As we age, parts of the macula may grow thin and collect tiny clumps of protein known as drusen. The dry form of macular degeneration is a result of this process, which in turn causes harm to the central vision.
Symptoms of Dry AMD:
- Limited central vision in one or both eyes while peripheral vision remains normal
- Trouble working or reading in dim light
- Blurred vision
- Seeing wavy or bent lines around objects in central vision
- Poor night vision
- Experiencing low vision that can’t be corrected with glasses or contact lenses
- Colors appear less vibrant
Wet age-related macular degeneration
In a majority of wet AMD cases, the onset is acute. A much smaller percentage of people with macular degeneration will have this variation and, in many instances, the wet form becomes an advanced stage of dry AMD. Wet macular degeneration occurs when blood vessels in the retina become blocked, thus generating the growth of new, abnormal blood vessels. The blood vessels may burst and leak fluid, hence the name “wet AMD”.
As a secondary disorder related to dry AMD, drusen blocks the flow of nutrients, prompting the eye to grow new blood vessels. This overabundance of mass in a small area then can lead to leakage and bursting, causing acute wet AMD.
Symptoms of Wet AMD:
- Haziness in overall vision
- Normally straight lines can appear bent or wavy
- Blurry spots in central vision
- Sudden onset and worsening symptoms after noticing slight vision changes
Diagnosis and Treatment for Dry AMD
A routine eye exam performed by an ophthalmologist can detect AMD, regardless of the type. If dry AMD is suspected, additional testing will be performed. These tests may include:
- Visual acuity. Similar to your standard eye exam, a visual acuity test shows how well you can see the details of shapes or letters from a specific distance. If you’ve had previous eye exams and were able to see letters from a certain distance, but are now suddenly unable to make them out, your ophthalmologist may investigate further.
- Dilated eye exam. Your eye doctor will place drops in both eyes to dilate the pupil. He or she will then use a special lens to peer through your eye and take stock of the condition of the retina, macula, and other components.
- Amsler Grid. Another form of vision test, the Amsler Grid leads the patient through a series of questions related to the construct of the grid, allowing eye doctors to gauge whether an individual may be experiencing AMD.
- Fluorescein angiography. As an injected yellow dye moves through the bloodstream, opthamologists take pictures of the eye when it passes through. This dye helps detect leakage or broken blood vessels.
- Optical coherence tomography (OCT). This test uses light waves to snap pictures of the retina in a criss-cross pattern, allowing your ophthalmologist to examine the various retinal layers.
Prevention is key and maintaining overall health reduces the risk for developing age-related macular degeneration. Detection of early AMD can reduce severe vision loss. Those who have already had vision loss may need further, more intensive treatments.
- Vitamins. An AREDS2 study and clinical trials sponsored by the National Eye Institute showed that vitamins and minerals stave off progression of dry AMD. These vitamins include vitamins C, A, E, zinc, and copper. Learn more about this study via the American Macular Degeneration Foundation.
There is no cure for dry macular degeneration but, through treatment with vitamins, the risk for incurring additional vision loss can be lessened.
Diagnosis and Treatment for Wet AMD
Diagnosing wet AMD is similar to diagnosing dry AMD. Additional testing is usually conducted to determine whether an individual has dry or wet AMD. Typically, Ophthalmologists will use the following tests:
- Preferential hyperacuity perimetry. With this test, the macula is scanned with a succession of stimuli in order for an ophthalmologist to determine where distortions appear.
- Fluorescein angiography. Dye is injected into the bloodstream and monitored as it passes through the eye. Yellow coloration will leak out into the eye if broken or compromised blood vessels exist.
Because wet AMD occurs suddenly, treatments are more aggressive than those related to dry macular degeneration.
- Laser surgery. Lasers are used to seal off leaking blood vessels and stop further vision impairment.
- Photodynamic therapy. Using a combination of lasers and medication, photodynamic therapy also seeks to seal off broken blood vessels.
- Anti-VEGF Therapy. Originally used as cancer treatments, anti-VEGF drugs halt the growth of blood vessels, preventing new ones from forming in the eye and worsening the central vision. Injections of anti-VEGF drugs are administered into the eye and antibiotics are usually prescribed to prevent infection afterwards.
Living with AMD.
Prevention and early detection of both dry and wet macular degeneration are key to mitigating greater complications. Routine eye exams with an ophthalmologist in Orlando help individuals maintain good eye health. UCF Health provides valuable information to help patients take charge of their own health care and maintain a high quality of life. Visit our patient portal to access additional resources, use our online scheduling tool, or even compare cataract surgery costs. It is our goal to ensure that healthful resources are available to all.