info@safwalaservision.com +2(03) 4222227
info@safwalaservision.com +2(03) 4222227
Age-related macular degeneration (AMD) is caused by the loss of retinal photoreceptor cells in the center of the retina where vision is the sharpest (the macula). The underlying cause of macular degeneration is still unknown.
There are two forms of age-related macular degeneration.
The most common symptom of dry AMD is slightly blurred vision and the need for brighter lights for reading. Many patients also report an inability to recognize faces at a distance. Initially, dry AMD may be limited to one eye and go unnoticed because of the ability of the other healthy eye to see clearly. As dry AMD progresses, a blurry spot develops in the center of the vision. With time, the spot may get bigger and darker, reducing central vision. There is no pain associated with any form of AMD.
Symptoms of wet AMD include rapid central vision loss or distortion. Straight lines, such as sentences on a page, may appear wavy. Patients may also notice a blurred or blind spot in the center of vision.
Macular degeneration is diagnosed through a dilated exam of the retina by an ophthalmologist. During this exam, the ophthalmologist may:
Ask the patient to look at a pattern of straight horizontal and vertical lines, known as an Amsler grid. (Patients with AMD may see wavy lines, distorted or missing lines, or a black spot in the center of the grid)
Perform a dilated examination of the retina to look for evidence of retinal photoreceptor damage.
Perform imaging tests such as optical coherence tomography (OCT) and fluorescein angiography to determine the extent of AMD.
Once a patient is diagnosed with dry AMD, they should be vigilant to check the vision in each eye, one at a time, at least once a day. By staring at the central point on an Amsler grid, patients can detect distortion of the grid surrounding the central point. These distortions may represent wet macular degeneration, which requires urgent treatment.
Age Related Eye Disease Study (AREDS) demonstrated that vitamin supplementation slowed the progression of dry AMD. This study demonstrated the benefits of taking Vitamin C, Vitamin E, beta-carotene, and zinc along with copper. Several preparations containing the appropriate amounts of these vitamins and micronutrients are currently available and we encourage patients with AMD to discuss these various vitamin preparations with their eye care specialist. Smoking is detrimental to patients with AMD, so quitting is recommended. All smokers should avoid beta-carotene, and instead take a vitamin formulation that contains lutein.
In eyes with wet AMD, a chemical called Vascular Endothelial Growth Factor (VEGF) causes abnormal blood vessels to grow under the retina. These blood vessels leak and bleed, causing damage to central vision. With these medicines, it is possible to improve vision and convert wet AMD back into the dry form.
Bevacizumab (Avastin) was the first effective treatment in clinical practice that had the potential not only to stop further deterioration in vision from wet AMD, but bring about significant improvement in vision for these patients.
Ranibizumab (Lucentis) In June 2006, the FDA approved Lucentis for the treatment of the wet form of AMD. Lucentis and Avastin are both manufactured by Genentech, Inc. and both drugs are derived from the same monoclonal antibody against VEGF and virtually perform the same function. Lucentis was engineered specifically for the eye and tested in rigorous Phase III trials. Like Avastin, Lucentis can improve visual acuity with over 35% of patients experiencing significant improvement.
