Diabetes and your eye

At Mid-North Eye Center in Chicago, for our treatment of diabetic eye disease, we want you to be well-informed about diabetes and your eye health.   Although we are eye specialists and not internal medicine doctors, we are concerned about your general health as well as your eye and we’ll make inquiries into your diet, weight loss or gain, sugar and cholesterol levels and blood pressure.  Consider us an integral part of your health care team!

·         The condition of your eyes is a window into your overall health.  Any signs of serious eye problems from diabetes or high blood pressure often serve as wake up call for you to better manage your disease.  We want you to see well and to live a healthy fulfilling life.

·         Thinking of your eye like a camera, the “film” of the eye is called the retina.   This critical structure can get damaged if your diabetes is not under good control for an extended period of time. Having poorly controlled high blood pressure worsens the situation.

·         Think of it this way.  If you run high levels of sugar in your system, the sugar is eventually broken down into a number of substances that are bad for your body. One such substance is strepkinase B, but there are many others.   Streptokinase B can damage the very small blood vessels of your body called capillaries. The retina receives its blood supply from these capillaries.

·         Two things are bad for capillaries. One thing that can happen is that the capillary wall can become leaky.   A structure called a pericyte lines the capillary wall and acts like cement to hold the capillary wall cells intact.  The streptokinase can damage the pericytes and then the capillaries can leak fluid into the retina.   The retinal does not function as well when it is “wet” so vision inevitably declines.  This is called retinal edema.  The center of the retina is called the macula. If the edema affects the macula and causes vision reduction, then clinically significant macular edema (CSME) is present.

·         Macular edema a form of non-proliferative diabetic retinopathy (NPDR) is swelling or thickening of the macula, the area in the center of the retina that allows us to see fine details.   NDPR is commonly known as background retinopathy.  In the early stages, tiny blood vessels within the retina leak blood or fluid. The leaking fluid causes the retina to swell or to form deposits called exudates.

Proliferative diabetic retinopathy (PDR) and ischemic maculopathy

These conditions are frequently associated with high blood pressure.

·         Instead of leaking too much fluid, capillaries can simply close off.  When the retina doesn’t get enough blood from capillaries it is called capillary non-perfusion.  If the capillary non-perfusion occurs in the center of the retina or macula,   visual acuity can dramatically decline (ischemic maculopathy).

·         Capillary non-perfusion in the retinal elicits the formation of a substance called vascular endothelial growth factor. (VEGF).   The VEGF signals to the retinal to produce new abnormal blood vessels. The new vessels are very delicate and may appear on the optic nerve (NVD, neovascularization of the disk) or in the retinal periphery (neovascularization of the peripheral retina).

·         The fragile new vessels may bleed into the vitreous, a clear, gel-like substance that fills the center of the eye. It may take days, months, or even years to resorb the blood, depending on the amount of blood present. . Patients describe loss of vision, large black spots in front of the vision, streaks in front of the vision, among other symptoms depending upon the size of the hemorrhage.

 If the eye does not clear the vitreous blood adequately within a reasonable time, vitrectomy surgery may be recommended.

Both proliferative diabetic retinopathy and vitreous hemorrhage are more likely to occur if patients with diabetes also have high blood pressure.

Traction retinal detachment:  When PDR is present, scar tissue associated with the neovascularization can shrink, wrinkling and pulling the retina from its normal position. Macular wrinkling can cause visual distortion. More severe vision loss can occur if the macula or large areas of the retina are detached.

How is diabetic retinopathy diagnosed?

·         At Mid-North Eye Center in Chicago, a medical exam is the only way to detect changes inside your eye. The ophthalmologist dilates your pupil and looks inside of the eye with an ophthalmoscope.   We also use specialized instruments such as the Cirrius OCT, which scan your retina to look for early subtle signs of disease that might not be readily appreciated on ophthalmoscope alone.

If disease is found, special test called fluorescein angiography (FA) is recommended. In this test, a dye is injected into your arm and photos of your eyes are taken.  The pictures are analyzed by our specialists for leakage, bleeding,  new blood vessel formation, capillary non-perfusion and other patholgy.  The FA is analyzed along with the OCT (ocular coherence tomography) test and a treatment plan is devised.

Laser surgery: Laser surgery is often recommended for people with macular edema or proliferative or proliferative diabetic retinopathy (PDR).  

·         For macular edema, the laser is focused on the damaged retina near the macula to decrease fluid leakage. The laser treats areas where the capillary beds are leaking fluid and seals them off.

·         The main goal of treatment is to prevent further loss of vision: in addition, many patients who have blurred vision from macular edema do recover some vision about a month or two after the treatment.  Of course keeping blood pressure, sugar levels and triglycerides under control are important.

·         For PDR, the laser is focused on all parts of the retina except the macula. This pan-retinal photocoagulation treatment causes abnormal new vessels to shrink and often prevents them from growing in the future. It also decreases the chance that vitreous bleeding or retinal distortion will occur.

Multiple laser treatments over time are sometime necessary. Laser surgery does not cure diabetic retinopathy and does not always prevent further loss of vision.

Vitrectomy:

·         In advanced PDR, the ophthalmologist may recommend a vitrectomy. During this microsurgical procedure, which is performed in the operating room, the blood –filled vitreous is removed and replaced with a clear solution. The ophthalmologist may wait for several months or up to a year to see if the blood clears on its own before performing a vitrectomy.

·         Vitrectomy often prevents further bleeding by removing the abnormal vessels that caused bleeding. If the retina is detached, it can be repaired during the vitrectomy surgery. Surgery should usually be done early because macular distortion or traction retinal detachment will cause permanent vision loss. The longer the macula distorted or out of place, the more serious the vision loss will be.

When to schedule an examination:

People with diabetes should schedule examinations at least once a year. More frequent medical eye examinations may be necessary after a diagnosis of diabetic retinopathy.

If you need to be examined for eyeglasses it is important that your blood sugar be consistently under control for several days when you see your ophthalmologist. Eye glasses that work well when the blood sugar is out of control will not work well when the blood sugar is stable.

Rapid changesin blood sugar can cause fluctuating vision in both eyes even if retinopathy is not present.

You should have your eyes checked promptly if you have visual changes that

·         Affect one eye only

·         Last more than a few days

·         Are not associated with a change in blood sugar.

When you are first diagnosed with diabetes, you should  have your eyes checked:

·         Within five years of the diagnosis if you are 29 years old or younger.

·         Within few months of the diagnosis if you are 30 years old and older.

At Mid-North Eye Center in Chicago, both Dr. Stone, a comprehensive ophthalmologist and Dr. Herbert Becker,  a retinal specialist, will be involved in your care.  Dr. Becker has a special interest in diabetic retinopathy and is well-versed in all aspects of its diagnosis and treatment.

Mid-North Eye Center in Chicago has  specialized instruments to diagnosis and treat diabetic retinopathy including fundus photography and angiography, OCT imaging, B-scan ultrasound testing and argon lasers.  

Our friendly staff will be happy to assist you in scheduling your first visit to our office.