Diabetic Retinopathy Treatment

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

Background Diabetic Retinopathy

In diabetes, the retinal blood vessels can develop tiny leaks. Blood and fluid seep from the retinal blood vessels, and fatty material, called exudate, deposits in the retina. This causes swelling of the retina, and it is called nonproliferative diabetic retinopathy (NPDR). When this occurs in the central part of the retina (the macula), vision will be reduced or blurred. Leakage elsewhere in the retina will usually have no effect on vision.

A patient with a wet, swollen macula, or with exudate in the macula, will experience some loss of vision, including blurring, distortion, or darkening. If one eye is affected, the other eye is frequently affected also, though the problem may not be equally severe in both eyes. If the diabetic retinopathy has affected each macula severely, central vision may be lost from each eye. But even if the ability to see detail has been lost from both eyes, the person with severe NPDR will usually be able to get along fairly well by learning to use the area just outside of the macula to see some detail. This ability to look slightly off center usually improves with time, though the eyesight will never be as good as it was before the macula was damaged by the leakage of blood vessels. So patients who have NPDR will usually be able to see well enough to take care of themselves and continue those activities that do not require detailed vision.

Early Diagnosis of Nonproliferative Diabetic Retinopathy

It is important that patients be aware of what they are seeing with each eye. If a patient can detect a problem with vision very early, the chance of saving eyesight with laser surgery is much greater. Once the macula has been damaged, laser surgery is generally not as helpful. For this reason, everyone should test the vision in each eye, separately, each day.

One way to test vision in order to detect even small changes when they first appear is to use the Amsler grid. Follow these instructions:

1. Wear your reading glasses and hold the Amsler grid at a normal reading distance.
2. Cover one eye.
3. Look at the center dot and keep looking at it at all times.
4. While looking directly at the center, be sure that all the lines are straight and all the small squares are the same size.
5. If you should notice any changes on the grid such as distortion, blur, discoloration, or other abnormality, and it stays that way for a few days, call and see your eye doctor right away.
6. Be sure to test the other eye in the same manner.

Laser Surgery for Diabetic Retinopathy

The laser is used to stop abnormal retinal blood vessels from leaking fluid into the retina. Vision does not usually improve with a laser, but laser treatments can frequently stop further loss of vision. When the swelling of the retina or amount of exudate in the macula has reached a critical stage, laser treatments should be performed so that vision does not deteriorate further. Your own doctor can help you evaluate your chances with laser surgery and discuss the options with you.

There are two types of laser surgery for NPDR: Focal (or specific) surgery and Grid surgery. With focal laser surgery, the specific leaking spots in the retina are found by a fluorescein angiogram, which is then used as a guide for the laser in an attempt to stop the leakage. In some patients, all of the leaking spots may be properly treated. In others, all of the leaking spots may be properly treated, but they may continue to leak, or new ones may develop. In such cases, further leakage causes more swelling and worsening of vision. Additional laser surgery frequently needs to be done in order to stop new leakage, but again, the vision is not likely to improve. In other situations, further laser surgery is not helpful and should not be done.

In some cases of NPDR, blood vessels appear to be leaking everywhere in the macula and not just in a few specific areas. In such cases, a scatter of laser energy in a grid pattern is placed across the entire swollen macular area. Grid laser surgery has a fair chance of drying the macula and holding vision stable. Grid surgery, however, infrequently improves vision. Again your doctor will help you evaluate whether specific (focal) or grid surgery, or a combination of the two, is best.

Grid Laser of Diffuse Diabetic Macular Edema

After the laser surgery, the patient will often see the many small spots caused by laser burns. With time, the spots tend to shrink and fade, and the patient will be less bothered by them, though they will always be there.

Even when laser surgery has successfully sealed the leaking vessels, new areas of leakage frequently appear later, causing more swelling and more loss of vision. The patient who is treated with laser should continue to check the vision in each eye daily and tell the doctor immediately if there are new changes, such as a return of distortion or blurriness. Vision does not usually improve with laser surgery, but if NPDR is discovered early enough, laser surgery may stop further loss.

Anti VEGF therapy for Diabetic Macular Edema

VEGF (Vascular endotheilial growth factor) is the chemical in the retina that causes blood vessels to leak resulting in diabetic macular edema. Recent studies have shown that anti-VEGF injections of either Avastin or Lucentis into the eye are very effective in treating diabetic macular edema.  Thus, either Anti-VEGF alone or in combination with laser treatment appears to be the better treatment for macular edema.  Studies however are ongoing.