Diabetic retinopathy is a complication of diabetes mellitus. Diabetes damages the normal circulation of the body. That is why diabetics have problems with the circulation to their legs, kidneys, heart, brain and eyes. Initially, diabetes causes the retinal vessels to leak resulting in retinal swelling (macular edema) and vision loss. The leaking vessels can be sealed with a laser to resolve the swelling and prevent further vison loss. Significant macular edema may be present even if your vision is excellent.

As diabetic retinopathy advances, the normal retinal vessels close (retinal ischemia). The retina now is not receiving adequate blood nourishment. In an effort to compensate for the lack of normal circulation, the retina grows new, abnormal blood vessels (proliferative diabetic retinopathy). The abnormal vessels are not helpful and can lead to severe loss of vision with bleeding, scar tissue growth, and retinal detachment. The abnormal blood vessel growth can be halted with timely laser treatment or surgical removal (vitrectomy surgery).

Just like macular edema, you can have severe abnormal blood vessel growth in your eye and still have excellent vision. It is important for diabetics to have at least a yearly eye exam to monitor for significant retinopathy. Early and aggressive treatment of diabetic retinopathy is extremely successful in preventing severe vision loss. In order to maximize the health of your retinal circulation, as well as the circulation to the heart and kidneys diabetics should lower their vascular risk factors: don't smoke, control hypertension, exercise, lower your cholesterol, eat a low fat diet and follow your family doctor's instructions.

Current Treatment Options for Vision Loss due to Diabetic Macular Edema

Diabetic macular edema (DME) causes vision loss due to two basic mechanisms:

1.  Edema: leakage from the damaged retinal vessels causes edema (swelling) of the macula (the center of the retina). Macular edema may damage retinal photoreceptors, sometimes permanently. Retinal surgeons often are able to restore vision lost due to DME.
2.  Ischemia: loss of circulation or blood supply is called ischemia.   Vision loss due to ischemia is permanent and not likely to be restored with any therapy. Most patients with severe vision loss due to DME have a combination of edema and ischemia.
The primary goal of treatment is to eliminate macular edema (swelling) in order to prevent additional vision loss.  Most patients (more than 50%) will achieve improved vision with successful treatment of their macular edema (though the vision is not likely to be 100% restored). The extent of the vision improvement depends on the extent of the edema, the degree of the vision loss and the underlying macular ischemia.

Laser only:  This is a well established treatment for DME. Laser treatments are very safe and offer good rates of vision stabilization. Often times multiple laser treatments are necessary to resolve all macular edema. Only a small percentage of patients will experience improved vision with just laser treatment. This is an ideal treatment option for patients who have DME that does not yet involve the center of the vision. Insurance plans cover this well established treatment.

Injections into the eye (intravitreal injection) with Anti-VEGF drugs in combination with laser: Recent clinical trials show that specialized biotechnology drugs may effectively relieve macular edema. Avastin and Lucentis injections have a very low risk profile. Typically, these injections are given on an every 4-6 week basis (you may require 10 injections a year for two years) until all macular edema (swelling) has resolved. Repetitive and aggressive treatment with Avastin or Lucentis is necessary to achieve the goal of visual improvement. Retinal laser in combination with intravitreal avastin or lucentis may increase the benefit of these injections. This is a relatively new and safe therapy. Insurance plans may not cover payment for intravitreal Avastin and Lucentis.

Intravitreal injections with long-acting steroids in combination with laser: This is a highly effective means of resolving DME. Typically, patients require 2-4 injections several months apart to resolve all retinal edema. Laser is used to combination with these steroid injections to increase benefit and duration of beneficial effect. Cataracts often worsen following steroid injections. In addition, there is a 25% chance of eye pressure elevation following steroid injections. Insurance plans cover this treatment plan.

Please consult with your retina specialist to determine the best course of treatment for you.