Diabetic Retinopathy Treatment

• Background Diabetic Retinopathy
• Proliferative Diabetic Retinopathy
• Traction Retinal Detachment
• Vitreous Hemorrhage

Proliferative Diabetic Retinopathy

Dr. Moises A. Chica, MD, and Dr. Calvin E. Mein, MD offer treatment for diabetic retinopathy and other vitreoretinal conditions at Retinal Consultants of San Antonio, serving San Antonio, Kerrville, New Braunfels, Castle Hills, Converse, Schertz, Hollywood Park, Kirby, Somerset, Castroville, Alamo Heights and the surrounding area. In PDR, retinal blood vessels close off, and large areas of retina lose their source of nutrition. When this happens, peripheral or side vision is usually reduced, and the patient’s ability to see at night and to adjust from light to dark is often diminished.

As a result of this loss of nourishing blood flow, the retina responds by developing new blood vessels that are abnormal and are called neovascularization. The development of neovascularization is the retina’s method of coping with the closing of its own blood vessels and the loss of nourishment. Many people with diabetes have some closing of retinal blood vessels without ever developing neovascularization. But the problem is that when neovascularization develops, it is never always a problem. It is, in fact, dangerous to the eye. Neovascularization does not nourish the retina properly, and it may cause other problems. One problem is bleeding into the vitreous cavity (called vitreous hemorrhage). A second problem that occurs when neovascularization develops is the growth of scar tissue on the retina; the scar tissue can pull the retina off the back wall of the eye (called a traction retinal detachment). Either of these serious problems, vitreous hemorrhage or traction retinal detachment, can lead to severe loss of vision or even total blindness.

A third problem that can occur is when neovascularization grows on the iris, the colored part of the eye, rather than just on the retina. When neovascularization grows on the iris (called rubeosis), it may close off normal flow of fluid out of the eye and cause the pressure in the eye to rise to dangerously high levels. The high pressure (called neovascular glaucoma) can cause permanent changes, resulting in visual loss, pain, or even loss of the eye.

It is very important to understand that the closing of retinal blood vessels and the development and growth of neovascularization may occur without any noticeable change of vision. So, it may be impossible for the person with diabetes and early PDR to know that such changes are occurring. For this reason, it is essential that every person with diabetes be examined regularly by a specialist who is familiar with diagnosing diabetic retinopathy. Such examinations should occur regularly–probably every six to twelve months, or more or less frequently–for the lifetime of the person with diabetes. The earlier neovascularization is discovered, the better the chance that laser surgery will save vision. The later neovascularization is discovered, the greater the chance for blindness.

All people with diabetes should be examined regularly to be sure that neovascularization is not developing. When neovascularization does develop, if the amount is not severe, laser surgery is not necessary as long as the patient is examined regularly.

If the amount of neovascularization is great, laser surgery can often prevent loss of vision. The type of laser surgery that is done when there is a lot of neovascularization is called pan retinal laser photocoagulation. This type of laser surgery is usually done in two or more separate sessions. The idea is to use the laser to destroy all of the dead areas of retina where the blood vessels have been closed. When these areas are treated with the laser, the retina stops manufacturing new blood vessels, and those that are already present tend to decrease or disappear.

Pan Retinal Photocoagulation

There are side effects of pan retinal laser photocoagulation and, for this reason, this surgery is not done when only a small amount of neovascularization is present. It is important to remember, however, that when the amount is great enough to warrant laser surgery, the longer the eye remains untreated the more likely vision will be lost and blindness will occur. The earlier severe neovascularization is discovered and the eye is treated with laser, the more likely blindness can be prevented. If you have developed neovascularization, your doctor will advise you about when pan retinal laser photocoagulation should be done.

Pan retinal laser photocoagulation does not improve vision, however, it is the best possible means of holding vision stable to prevent further loss. After laser surgery, patients may still have reduced vision or may continue to lose more vision. But if pan retinal laser photocoagulation is indicated, the chances are that it will prevent severe loss of vision.

Pan retinal laser photocoagulation is placed on the side (periphery) of the retina, not on the center, and side (peripheral) vision will definitely be diminished to some extent. These side areas are sacrificed in order to save as much of the central vision as possible and to save the eye itself. Night vision will also be diminished. After laser, blurred vision is very common. Usually, this blur goes away, but in a small number of patients, some blur will continue forever.

Because diabetic retinopathy can occur at any time, the patient who is treated with laser for either NPDR or PDR should have regular retinal examinations by an eye specialist.