What is the Macula?
The macula is a sensitive region of the retina at the back of the eye. It contains many nerve cells that detect visual stimuli, allowing the eye to perceive the details of the objects of focuses in the central vision. When you read or recognize faces, you are using your macula. For reasons that are not fully understood, as certain people age, the macula breaks down and drusen deposits develop. When this occurs, it interferes with vision. Over time, macular degeneration can even cause blindness. In fact, according to the CDC, the leading cause of permanent vision impairment in people over 65 is macular degeneration.
AMD Risk Factors
The most significant risk factor for developing AMD is age. Pre-symptomatic signs can sometimes be detected as early as 40 using advanced diagnostic eye care technology, but we say macular degeneration mostly affects people over 60. Everyone in this age group should have a comprehensive eye exam yearly including a screening for AMD. This eye disease is hereditary, so people with a family history of AMD or vision loss of an unknown cause have a much higher risk of developing it, and they are encouraged to begin annual eye exams at a younger age to screen for macular degeneration. Smoking greatly increases the chances of developing AMD. The American Academy of Ophthalmology recently noted that obesity and high blood pressure have also been shown to be associated with higher incidences of macular degeneration.
Dry AMD and Wet AMD
There are two catagories of Macular Degeneration: Dry and Wet. Dry macular degeneration is more common and less severe. It leads to more gradual blurring of central vision. If dry AMD is caught and treated early, the progression toward vision loss can be prevented to some extent. Recent studies (AREDS 2) show that taking nutritional supplements with high doses of certain vitamins and antioxidants like lutein, zeaxanthin were able to reduce macular degeneration.
Wet macular degeneration, while less common, is often much more devastating. It tends to progress more quickly and lead to more profound vision loss. Wet AMD is characterized by the overgrowth of abnormal blood vessels behind the retina under the macula. These blood vessels leak fluid and blood, and cause scarring of the sensitive eye tissue. Early symptoms include straight lines that appear wavy. Untreated advanced wet AMD leads to blindness.
At this time, there is no cure for macular degeneration. However, there are treatment options for AMD. As mentioned above, we usually treat dry macular degeneration with supplements that can reduce disease progression, and lifestyle changes such as quitting smoking and managing systemic risk factors.
Wet macular degeneration often requires more aggressive treatments, including:
- Anti-angiogenic medications that are injected directly into the eye to prevent angiogenesis and hemorrhaging (abnormal growth and leaking of blood vessels) at the back of the eye. Some patients have even regained some eyesight after having this treatment. However, it may need to be repeated.
- Laser therapy can destroy actively growing blood vessels and prevent subsequent bleeding, leaking, and scarring of the retina. A related technology, called photodynamic laser therapy includes injecting a light-sensitive drug intravenously, and then activating it in the eye using a laser.
Beyond invasive interventions, we seek to help people with macular degeneration cope with symptoms like vision loss. Low vision aids are special devices that make the best of remaining eyesight. These may include lighting adjustments, high contrast enhancements, specialized lenses, magnifiers and a number of other approaches.
On the horizon, there are many groups researching macular degeneration treatment and prevention. Some of these experimental treatments for AMD include various forms of eye surgery, laser treatments, and radiation therapy. Oral medications may also be an option for treating macular degeneration in the future. Others practitioners are testing the effectiveness and safety of certain cancer medications for use in macular degeneration patients. Early clinical trials are looking at injecting antibodies in to the eye to target abnormal blood vessel growth and inflammation. There may be eye medications that will be able to be applied to the surface of the eye either as an eye drop or a spray which will be able to restore healthy blood flow to the retina. Stem cell treatment, gene therapy, and artificial or transplanted retinas may one day open doors to those with vision loss from macular degeneration.
In the meantime, our Practice focuses on early detection of macular degeneration and treatments that have been well-researched and proven to be safe and effective.