What is diabetic retinopathy?
Diabetic retinopathy is the most common diabetic eye disease which may lead to blindness. It is caused by changes in the blood vessels of the retina (which is the light sensitive tissue at the back of the eye). A healthy retina is necessary for good vision.In some people with diabetic retinopathy, blood vessels may swell and leak fluid. In others, abnormal new blood vessels may grow on the surface of the retina.If you have diabetic retinopathy, at first you may not notice changes to your vision. But over time, diabetic retinopathy can get worse and cause vision loss. It usually affects both eyes.
How does diabetic retinopathy cause vision loss?
- Fragile, abnormal blood vessels can develop and leak blood into the center of the eye, blurring vision.
- Fluid can leak into the center of the macula, the part of the eye where sharp,straight-ahead vision occurs. The fluid makes the macula swell (macular edema) causing blurring of vision. It is more likely to occur as the disease progresses.
Who are at risk for diabetic retinopathy?
- All people with diabetes--both type 1 and type 2--are at risk. That's why everyone with diabetes should get a comprehensive eye check up at least once a year. If you have diabetic retinopathy, your doctor can recommend treatment to help prevent its progression.
- During pregnancy, diabetic retinopathy may be a problem for women with diabetes.
- Persons having high blood pressure or abnormal blood cholesterol levels are more prone to develop diabetic retinopathy.
What are the symptoms of diabetic retinopathy?
You may have diabetic retinopathy for a long time without noticing any symptoms.Typically, retinopathy does not cause noticeable symptoms until significant damage has occurred and complications have developed.Symptoms of diabetic retinopathy and its complications may include:
- Blurred or distorted vision or difficulty in reading.
- Floaters(shadows or dark objects that float across your field of vision).
- Partial or total loss of vision .
- Pain in the eye.
What type of exam and test need to detect diabetic retinopathy?
- Visual acuity test. This eye chart test measures how well you see at variousdistances.
- Slit Lamp Exam. This is to see interior of the eyeball under magnification.
- Tonometry. An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
- Dilated eye exam. Drops are placed in your eyes to widen, or dilate, the pupils. This is a special investigative test done for certain indications (after excluding contra indications). This allows the doctor to see more of the backside of your eyes to check for signs of retinopathy and presence of cataract. After the exam, your vision may remain blurred for approximately 6 hours. You will not be able to read and drive for 6 hours.
- Fluorescein angiogram. In this test, a special dye is injected into your arm. Pictures are taken as the dye passes through the blood vessels in your retina.
The test allows your doctor to identify any leaking blood vessels and recommend treatment.
Your doctor checks your retina for early signs of the disease, including:
- Leaking blood vessels.
- Retinal swelling (macular edema).
- Pale, fatty deposits on the retina--signs of leaking blood vessels.
- Damaged nerve tissue.
- Any changes to the blood vessels.
- Presence or absence of diabetic retinopathy which is usually graded as mild,
How is diabetic retinopathy treated?
Annual dilated eye exam is mandatory even if you do not have any visual symptoms.DO NOT CONFUSE IT WITH SPECTACLE TESTING During the initial stages of diabetic retinopathy, no treatment is needed, unless you have macular edema. To prevent progression of diabetic retinopathy, people with diabetes should control their levels of blood sugar, blood pressure, and blood cholesterol.
In advanced retinopathy laser photocoagulation may be needed. This procedure is called scatter laser treatment which helps to shrink the abnormal blood vessels. Three or more sessions usually are required to complete treatment. Although you may notice some loss of your side vision, your color vision and night vision, scatter laser treatment can save the rest of your sight and prevents from blindness. Scatter laser treatment works better before the fragile, new blood vessels have started to bleed. That is why it is important to have regular, comprehensive dilated eye exams. Even if bleeding has started, scatter laser treatment may still be possible, depending on the amount of bleeding.
In a few cases, if the bleeding is recurrent in spite of laser treatment, you may need a surgical procedure called a vitrectomy in which blood is removed from the center of your eye.
How is a macular edema treated?
Macular edema is treated with laser surgery. This procedure is called focal laser treatment. Your doctor places up to several hundred small laser burns in the areas of retinal leakage surrounding the macula. These burns slow the leakage of fluid and reduce the amount of fluid in the retina. The surgery is usually completed in one session in some cases. Further treatment may be needed. If you have macular edema in both eyes and require laser surgery, generally only one eye will be treated at a time, usually several weeks apart. Simultaneously with the laser treatment Blood Pressure, Blood Sugar, serums and lipids should be well controlled.
What are the key safety points of diabetic retinopathy?
- Annual eye exam or earlier.
- Regular check up of IOP.
- Control of Blood Sugar value (HbA1c<6.5).
- Control of Blood Pressure.
- Lowering of lipids.
- Even after laser treatment, follow up with your eye specialist is must which should be 3-6 monthly.
- The aim of laser treatment is to prevent the patient from blindness or from sight threatening complications. It does not usually improve the existing vision.