DIABETIC RETINOPATHY: LEADING CAUSE OF BLINDNESS IN WORKING AGE ADULTS
From Washington University Physicians, posted February 21, 2012, written by Mary Jo Blackwood, RN, MPH
Diabetic retinopathy, damage to the eye’s retina, is caused by complications of diabetes and can eventually lead to blindness.
Eye changes occur in up to 80 percent of patients who have had diabetes for ten years or more. Until the late1900s, diabetic retinopathy lead to blindness almost 100 percent of the time.
Washington University ophthalmologist and vitreoretinal surgeon Dr. Rajendra Apte says there are now excellent treatments for this condition, and more are being discovered all the time, potentially reducing that risk to just ten percent or less.
Because diabetes mellitus is a systemic disease, the retina is less likely to be affected with good blood sugar control and adequate management of co-morbidities such as hypertension. People with both Type 1 and Type 2 diabetics are at risk: type 1 because the disease starts earlier and tends to be harder to control; and type 2, because poor control of blood sugar, blood pressure and cholesterol significantly increase the risk for eye problems.
Diabetic Eye Changes
Apte says the main threats from diabetic retinopathy include damage to the small blood vessels in the retina causing swelling of the macula (central part of the retina), development of abnormal compensatory blood vessels which bleed, and ultimately, retinal detachment.
Every diabetic patient should have a comprehensive biomicroscopic eye exam to determine level and severity of the condition; the results will then dictate frequency of future evaluations and possible treatment.
Don’t take these eye exams lightly, he says. While wet macular degeneration, which also affects the retina, is the main cause of blindness in adults over 60, diabetic retinopathy is the leading cause of blindness in working-age adults who have decades to live, making the quality-of-life issues significant.
Says Apte, “Newer treatments are so much less traumatic to the eye and so much more effective that we can, in many cases, restore lines of vision on the eye chart and head off dire complications by acting promptly.
Coordinated diabetes care involving both the internist and the ophthalmologist significantly reduces the chance of blindness and death from other diabetes complications. It is not uncommon to identify diabetes on an eye exam in an individual unaware of it.
Intravitreal pharmacotherapy for both decreasing edema (swelling) in the retina’s macula and stopping blood vessel proliferation is similar to treatment for macular degeneration. For both, drugs are injected directly and painlessly into the eye. Several agents are being intensively studied in clinical trials.
Laser photocoagulation: A laser can be used at different powers to address different problems. Used at a lower power it can stimulate certain tissues in the eye to normalize swelling, often very effectively when used in conjunction with the eye injections.
When diabetes damages the lining of blood vessels, reducing the amount of oxygenation and nutrients to the retina, the body responds by growing new blood vessels that are abnormal and can leak into the eye, leading to scar tissue formation and retinal detachment. A higher power laser is used to destroy these sick areas in the retina and decrease the signals to produce new blood vessels. In combination with injections, it can cause regression of those vessels.
These treatments don’t work for everyone, especially if they come to the doctor late in the disease process. There may be so much bleeding into the eye the body can’t clear it and these treatments aren’t effective. In those cases, surgery may be needed to clear the blood from the eye or to prevent retinal detachment.
Vitrectomy is a surgical procedure that cuts out the vitreous, the gel that fills the back of the eye, removing the blood in it that is obscuring the vision and any scar tissue that could pull the retina loose. Apte uses this analogy: “Like the appendix that is important when we are young but a liability sometimes as we age, the vitreous helps the eye develop correctly, but later on can become a scaffold for abnormal blood vessels. We can remove the gel and treat the walls of the eye with lasers and injections, removing any scar tissue and making sure the retina is firmly attached. Patients can end up with better vision after surgery.”
Just being in a clinical trial seems to help diabetes control. Clinical trials are underway at the University for diabetic retinopathy treatment. Referring physicians may have patients who qualify.