Vitreo-Retinal Conditions & Procedures
Age-related Macular Degeneration and Nutritional Supplements
Age-related macular degeneration (AMD) is a disease caused by damage or breakdown of the macula, the small part of the eye's retina that is responsible for our central vision. This condition affects both distance and close vision and can make some activities (like threading a needle or reading) very difficult or impossible. Macular degeneration is the leading cause of severe vision loss in people over 65.
Although the exact causes of AMD are not fully understood, a recent scientific study shows that antioxidant vitamins and zinc may reduce the effects of AMD in some people with the disease.
Among people at high risk for late-stage macular degeneration (those with intermediate AMD in both eyes or advanced AMD in one eye), a dietary supplement of vitamins C, E, and beta-carotene, along with zinc, lowered the risk of the disease progressing to advanced stages by about 25% to 30%. However, the supplements did not appear to benefit people with minimal AMD or those with no evidence of macular degeneration.
Light may affect the eye by stimulating oxygen, leading to the production of highly reactive and damaging compounds called free radicals. Antioxidant vitamins (vitamins C and E and beta-carotene) may work against this activated oxygen and help slow the progression of macular degeneration.
Zinc, one of the most common minerals in the body, is very concentrated in the eye, particularly in the retina and macula. Zinc is necessary for the action of over 100 enzymes, including chemical reactions in the retina. Studies show that some older people have low levels of zinc in their blood. Because zinc is important for the health of the macula, supplements of zinc in the diet may slow down the process of macular degeneration.
The levels of antioxidants and zinc shown to be effective in slowing the progression of AMD cannot be obtained through your diet alone. These vitamins and minerals are recommended in specific daily amounts as supplements to a healthy, balanced diet.
It is very important to remember that vitamin supplements are not a cure for AMD, nor will they restore vision you may have already lost from the disease. However, specific amounts of certain supplements do play a key role in helping some people at high risk for advanced AMD to maintain their vision. You should speak with your ophthalmologist (Eye M.D.) to determine if you are at risk for developing advanced AMD and to learn if supplements are recommended for you.
Floaters and Flashes
Small specks or clouds moving in your field of vision as you look at a blank wall or a clear blue sky are known as floaters. Most people have some floaters normally but do not notice them until they become numerous or more prominent.
In most cases, floaters are part of the natural aging process. Floaters look like cobwebs, squiggly lines, or floating bugs. They appear to be in front of the eye but are actually floating inside. As we get older, the vitreous (the clear, gel-like substance that fills the inside of the eye) tends to shrink slightly and detach from the retina, forming clumps within the eye. What you see are the shadows these clumps cast on the retina, the light-sensitive nerve layer lining the back of the eye.
The appearance of flashing lights comes from the traction of the vitreous gel on the retina at the time of vitreous separation. Flashes look like twinkles or lightning streaks. You may have experienced the same sensation if you were ever hit in the eye and "saw stars."
Floaters can get in the way of clear vision, often when reading. Try looking up and then down to move the floaters out of the way. While some floaters may remain, many of them will fade over time.
Floaters and flashes are sometimes associated with retinal tears. When the vitreous shrinks, it can pull on the retina and cause a tear. A torn retina is a serious problem. It can lead to a retinal detachment and blindness. If new floaters appear suddenly or you see sudden flashes of light, see an ophthalmologist (Eye M.D.) immediately.
A retinal detachment is a very serious problem that usually causes blindness unless treated. The appearance of flashing lights, floating objects, or a gray curtain moving across the field of vision are all indications of a retinal detachment. If any of these occur, see an ophthalmologist (Eye M.D.) right away.
As one gets older, the vitreous (the clear, gel-like substance that fills the inside of the eye) tends to shrink slightly and take on a more watery consistency. Sometimes as the vitreous shrinks, it exerts enough force on the retina to make it tear.
Retinal tears can lead to a retinal detachment. Fluid vitreous, passing through the tear, lifts the retina off the back of the eye like wallpaper peeling off a wall. Laser surgery or cryotherapy (freezing) are often used to seal retinal tears and prevent detachment.
If the retina is detached, it must be reattached before sealing the retinal tear. There are three ways to repair retinal detachments. Pneumatic retinopexy involves injecting a special gas bubble into the eye that pushes on the retina to seal the tear. The scleral buckle procedure requires the fluid to be drained from under the retina before a flexible piece of silicone is sewn on the outer eye wall to give support to the tear while it heals. Vitrectomy surgery removes the vitreous gel from the eye, replacing it with a gas bubble, which is slowly replaced by the body's fluids.
Vitrectomy is a type of eye surgery used to treat disorders of the retina (the light-sensing cells at the back of the eye) and vitreous (the clear gel-like substance inside the eye). It may be used to treat a severe eye injury, diabetic retinopathy, retinal detachments, macular pucker (wrinkling of the retina), and macular holes.
During a vitrectomy operation, the surgeon makes tiny incisions in the sclera (the white part of the eye). Using a microscope to look inside the eye and microsurgical instruments, the surgeon removes the vitreous and repairs the retina through these tiny incisions. Repairs include removing scar tissue or a foreign object if present.
During the procedure, the retina may be treated with a laser to reduce future bleeding or to fix a tear in the retina. An air or gas bubble that slowly disappears on its own may be placed in the eye to help the retina remain in its proper position, or a special fluid that is later removed may be injected into the vitreous cavity.
Recovering from vitrectomy surgery may be uncomfortable, but the procedure often improves or stabilizes vision. Once the blood- or debris-clouded vitreous is removed and replaced with a clear medium (often a saltwater solution), light rays can once again focus on the retina. Vision after surgery depends on how damaged the retina was before surgery.
Face-Down Recovery After Retinal Surgery
The retina is a layer of light-sensing cells lining the back of your eye. As light enters your eye, the retina converts the rays into signals that are sent through the optic nerve to your brain, where they are recognized as images.
To repair a damaged or detached retina, your ophthalmologist may remove some of your eye's vitreous (the gel-like substance that fills the inside of your eye) and inject a gas bubble into the eye to take its place. This bubble holds the retina in place as it re-attaches to the back of your eye. With time, the bubble disappears and is replaced with your normal eye fluid.
You must keep your head facing downward or turned to a particular side for up to several weeks after surgery so that the bubble will remain in the right position. In some cases the positioning requirements are full-time, and in others it may be part-time. If you lie in the wrong position, such as face-up, pressure may be applied to other parts of the eye, causing further problems like cataract or glaucoma. To assist you in keeping your face pointed downward, special equipment is available, including adjustable face-down chairs, tabletop face cradles, face-down pillows, and mirrors.