The inside layer of the back of the eye is called the retina. The retina is like the film of a camera. The central 10% of the retina is called the macula. The macula is responsible for sharp, central vision required for “straight ahead” vision activities, such as driving, reading, recognizing faces, and performing close up work.
Age Related Macular Degeneration (AMD) is a deterioration or breakdown of the macula and is one of the most common causes of poor vision in people over age 60. The visual symptoms of AMD involve the loss of central vision (reading, recognizing faces, etc.), while peripheral vision is unaffected. While age is the most significant risk factor for developing AMD, heredity, blue eyes, high blood pressure, cardiovascular disease, and smoking have also been identified as risk factors.
While AMD is one disease, it may be categorized into two forms.
The most common form of AMD is the dry form (called atrophic or non-exudative). Dry AMD is associated with thinning and slow deterioration of the retinal cells in the macula. It is usually slowly progressive and may take many years to develop. You may hear terms like drusen (white or yellow deposits), retinal pigment epithelial changes, and atrophy. These terms describe the appearance of the macula in dry AMD.
Some factors involved in the degenerative process of the macula, such as our gender and genetics, are beyond our control. However, clinical studies have shown that the effect of one important factor, free radicals, can be reduced to some extent.
Every day, our eyes are exposed to blue light waves that generate “free radicals” that can damage DNA and the light-sensing structures of the eye’s retina. Vitamins E and C, minerals zinc, copper, and selenium, and plant pigments lutein and zeaxanthin appear to have some protective value. Lutein and zeaxanthin, in particular, have been shown to be effective in reducing the effects of free radicals by helping the macula to filter out blue light.
Egg yolks and dark green, leafy vegetables such as spinach are rich in these minerals. Taking a nutritional supplement that contains these vitamins, minerals, and pigments can make it easier to include the proper amounts in your everyday diet. Use common sense and consult your physician before adding nutritional supplement to your diet, particularly if you are pregnant, breastfeeding, have a medical condition, or are taking a conflicting medications. Be aware that the concentration of zinc in these supplements has been shown to be effective in protecting eye health but may not be appropriate for everyone.
Steps to take:
- Ensure proper diet and nutritional supplement
- Protect your eyes from sunlight (sunglasses, hat, etc.)
- Don’t smoke
- If diagnosed with macular degeneration, monitor your vision with an Amsler grid.
Directions for Use of Amsler Grid
Click here to download the Amsler Grid
1. With your reading glasses on, test ONE eye at a time while holding grid at normal reading distance.
2. Look at the dot in the center of the page for three seconds with each eye.
3. All the lines should be straight.
4. If the lines become wavy, or if part of the grid is missing, notify our office immediately.
5. Test each eye for three seconds, once per week.
The wet form of AMD (called exudative) is much less common, but can produce rapid visual distortion and loss, and can be much more serious. This is not a separate condition, but is a complication of dry AMD. All patients with dry AMD should be monitored for the development of the wet form.
In this condition, abnormal blood vessels may grow into the macula from a layer beneath the retina, leaking fluid and blood, creating distortion or a large blind spot in the center of your vision.
Treatment of “Wet” AMD
If the blood vessels are not growing beneath the center of the macula, laser treatment is sometimes effective. In many cases, the location of the blood vessels make laser treatment unsafe. In these cases, treatment with anti-VEGF (vascular endothelial growth factor) intravitreal injections may be appropriate. These injections have shown a significant benefit in the treatment of wet AMD.
Low-vision high intensity reading lamps, magnifiers, iPads or other readers, and other low-vision aids help people with AMD make the most of limited vision. Also, consider large print reading materials and books on tape.