Common Diseases

Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss worldwide and typically affects individuals 50 years of age or older. As life expectancy increases, the disease is becoming a significant problem. The disease affects the part of the retina called the macula, which is responsible for central vision. Central vision enables us to read, drive, sew and perform other tasks that require detailed vision. Vision loss from AMD typically occurs gradually and can affect both eyes at different rates. Even though macular degeneration can cause visual impairment, the disease usually does not cause peripheral (side) vision loss or lead to total blindness.

Types

The two common types of macular degeneration are "dry" and "wet."

  • "Dry" form - the most common form of macular degeneration is caused by aging and thinning of the tissues of the macula. It develops slowly and usually causes mild vision loss. As this form of the disease develops, people often notice a dimming of vision while reading.
  • "Wet" form - rare, and more severe. Less common than dry AMD, but with the potential to create a large blind spot in the center of the visual field. This progresses rapidly, causing significant central vision loss.

The causes of macular degeneration are not completely understood. Some scientists believe heredity may play a part, as well as UV light exposure, nutrition, and cigarette smoking. Studies are ongoing.

Symptoms

  • A dark area or a "white-out" appears in the center of vision
  • Blurred or fuzzy vision
  • Color perception fades or changes
  • Straight lines, such as sentences on a page or telephone poles, appear wavy or distorted

Treatment

  • "Dry" form - There is no proven effective treatment for dry macular degeneration. Low vision rehabilitation can help those with significant vision loss to maintain excellent quality of life. High dose antioxidant vitamin therapy may help prevent some patients with dry macular degeneration from developing the wet form of the disease.
  • "Wet" form - a variety of therapies are available for wet macular degeneration; including intravitreal injection, photodynamic therapy, and rarely laser photocoagulation.

Low Vision Rehabilitation

This can help people who have experienced mild to severe vision loss adjust to their condition and continue to enjoy active and independent lifestyles. Low Vision Rehabilitation may involve anything from adjusting the lighting in your home to learning to use low vision aids to help you read and perform daily tasks. RCH works with Dr. Stanley Woo, O.D. for low vision rehabilitation.

Diabetic Retinopathy

The cells in persons with diabetes mellitus have difficulty using and storing sugar properly. When blood sugar gets too high, it can damage the blood vessels in the eyes. This damage may lead to diabetic retinopathy.

Types Of Diabetic Retinopathy

  • Background or nonproliferative diabetic retinopathy - blood vessels in the retina are damaged and can leak fluid or bleed. This causes the retina to swell and form deposits called exudates.

    Many patients may not notice any change in their vision when they develop this early form of the disease, but it can lead to other more serious forms of retinopathy that severely affect vision. Fluid collecting in the macula is called macular edema and may cause difficulty with reading and other close work.
  • Proliferative diabetic retinopathy - new, fragile blood vessels grow on the surface of the retina. These new blood vessels are called neovascularization, and can lead to serious vision problems, because the new vessels can break and bleed into the vitreous. When the vitreous becomes clouded with blood, light is prevented from passing through the eye to the retina. This can blur or distort vision and frequently causes sudden and severe loss of vision. The new blood vessels can also cause scar tissue to develop, which can pull the retina away from the back of the eye. This is known as retinal detachment, and can lead to blindness if untreated. In addition, abnormal blood vessels can grow on the iris (the colored part in the front of the eye), which can lead to severe glaucoma.

Treatment of Diabetic Retinopathy

Good control of diabetes with intensive management and control of blood sugar will delay, and possibly prevent, both the development and progression of diabetic retinopathy.
Patients with diabetic retinopathy frequently need to have special photographs of the retina taken. This series of photos is called fluorescein angiography.

  • Laser photocoagulation is one of the most common treatments for diabetic retinopathy. Focal photocoagulation consists of laser directed at the retina to seal leaking blood vessels in patients with background diabetic retinopathy. Panretinal photocoagulation consists of laser spots scattered through the sides of the retina to reduce abnormal blood vessel growth (neovascularization) and help seal the retina to the back of the eye in patients with proliferative diabetic retinopathy. This can help prevent retinal detachment. There is little recuperation needed after laser surgery for diabetic retinopathy. Laser surgery may require more than one treatment to be effective.
  • Vitrectomy surgery is performed for patients with very advanced proliferative diabetic retinopathy or retinal detachment. In vitrectomy, the surgeon removes the blood-filled vitreous and replaces it with a clear solution. This allows light to pass through the clear fluid to the retina, where the images are conveyed to the brain.
  • Pharmacotherapy: Increasingly, a variety of medications are being used to treat the manifestations of background and proliferative diabetic retinopathy. These involve intravitreal injections of small amounts of medication into the eye.

The type of retinopathy, as well as the patient's general health and eye structure, will determine the kind of treatment needed and the type of anesthesia utilized.

Flashes & Floaters

Some people may occasionally see small specks or clouds moving in your field of vision. These are called floaters. Floaters are actually tiny clumps of gel or cells inside the vitreous, the clear jelly-like fluid that fills the inside of the eye. While these objects look like they are in front of the eye, they are actually floating inside.
When people reach middle age, the vitreous gel may start to thicken or shrink, forming clumps or strands inside the eye. The vitreous gel pulls away from the back wall of the eye, causing a posterior vitreous detachment. Posterior vitreous detachment is more common in people who:

  • Are nearsighted
  • Have undergone cataract operations
  • Have had YAG laser surgery of the eye
  • Have had inflammation inside the eye

When the vitreous shrinks, it tugs on the retina, creating a sensation of flashing lights. The flashes of light can appear off and on for several weeks or months. As we grow older, it is more common to experience flashes.
As the shrinking vitreous gel pulls away from the wall of the eye, it can cause a retinal tear in places where the vitreous gel sticks too tightly to the retina. This sometimes causes a small amount of bleeding in the eye that may appear as new floaters. A torn retina is always a serious problem, since it can lead to a retinal detachment.

Retinal Tear & Detachment

What is a retinal detachment?

As the vitreous gel in the back of the eye starts to liquefy, it can separate from the retina, a condition called vitreous detachment. If the vitreous gel adheres too firmly to the retina, a retinal tear can occur with a vitreous detachment. A retinal detachment occurs when fluid leaks through the tear and separates the retina from the back of the.

Symptoms:

Patients with a retinal tear or detachment often, but not always, have flashes and floaters as their first symptoms. This occurs as the vitreous gel detaches from the back of the eye. Other patients may have very few symptoms. Patients may describe a "curtain" being drawn across the peripheral vision or decreased peripheral vision. If untreated, most retinal detachments will cause progressive loss of vision and eventually total blindness.

Treatment:

In most instances, retinal tears are treated with laser photocoagulation which acts to "spot weld" the retina to the back of the eye. In some cases pneumatic retinopexy is used to treat retinal detachment in the office without the need of surgery. In most cases, however, surgery is usually required. This consists of scleral buckling, vitrectomy, or a combination of the two procedures. These are usually performed as outpatient surgeries and may involve using a gas bubble to help push the retina back into position.