Diagnosing Diabetic Retinopathy
How is diabetes classified?
How is diabetic retinopathy classified?
What are the symptoms to look for?
What is a fluorescein angiogram?
What is an OCT study?
Does the development of either form of retinopathy mean that I have done something wrong in the care of my diabetes?
Can diabetic retinopathy be prevented?
How frequently should a patient with diabetes have a retina examination?
Type 1 diabetes was previously called insulin-dependent diabetes or juvenile-onset. This form is usually diagnosed in children and young adults and accounts for 5-10 percent of all cases of diabetes.
Type 2 diabetes was previously called non-insulin-dependent, or adult-onset, diabetes and it accounts for about 90-95 percent of all case of diabetes. Type 2 is associated with older age, obesity, family history of diabetes, physical inactivity, prior history of gestational diabetes, and race. African Americans, Native Americans and Latino Americans are at particularly high risk for type 2 diabetes. Type 2 diabetes is increasingly being diagnosed in children and adolescents along with increased obesity in the U.S.
- Non-proliferative diabetic retinopathy, which involves swelling within the eye, but no abnormal formation of blood vessels
- Proliferative diabetic retinopathy, in which abnormal new blood vessel form in the retina and vitreous gel of the eye
Unfortunately, diabetic retinopathy gives no warning symptoms. By the time a patient notices floaters or visual loss, there is already a significant amount of diabetic retinopathy. With proper education and attention, diabetic patients should seek regular eye examinations for better preventive care. With proper treatment, loss of vision can be prevented.
Fluorescein angiography is frequently used in the management of diabetic retinopathy. Fluorescein dye is injected into an arm vein, and as it courses through the retina, special pictures are taken of the interior of the eye by a professional photographer. It is a very informative tool used to evaluate retinal circulation, presence of macular leakage and retinal new blood vessels. Based on this information, the ophthalmologist will then determine whether treatment is necessary.
Most people tolerate fluorescein angiography very well. Some may experience a minor allergic reaction with rash and small hives that are easily treated with Benadryl. However, there is a very small risk (~1/200,000) of developing anaphylactic shock, which is an extreme allergic reaction that can lead to serious complications, including death. This is why patients are asked to give a signed consent prior to the study.
OCT is short for optical coherence tomography. It is a non-invasive study that provides a quick scan of the central area of the retina, called the macula. With this study, the ophthalmologist can quickly determine if there is fluid in the macula and in which layer of the macula. It is also very useful for treatment follow-ups as it provides objective data with exact measurements of the macular thickness.
No. Even with excellent control, many patients will still develop retinopathy. As patients may have severe proliferative diabetic retinopathy without any obvious visual symptoms, we recommend a baseline eye examination followed by regular examinations. Patients and their primary care physicians should not rely on vision as an indicator for need of an eye examination. There are no early warning signs for patients with diabetic retinopathy, making regular check-ups all the more necessary.
The most effective strategy to prevent the development of diabetic retinopathy is prevention of diabetes and attention to its risks. It is possible to prevent or delay the onset of type 2 diabetes by reducing lifestyle risk factors through weight control and increased physical activity. We hope that proper education and guidance can help patients with diabetes to reduce their risk of ocular complications. In particular, people with diabetes can learn to control their blood glucose levels, blood pressure and cholesterol levels, and receive regular checkups. People who smoke should stop smoking. People with diabetes who are overweight should develop a healthier diet and exercise regimen under the guidance of a health care provider.
Studies have shown that better control of blood sugar levels slows down the progression of retinopathy and delays the onset. The same studies have also shown that tight control of blood sugars also reduces kidney and neurological foot complications.
An adult patient with diabetes should have a thorough dilated retina examination at the time of diagnosis. This should be followed by yearly examinations for life. Some patients may require more frequent examination, and this will be determined by the physician. Young people with diabetes should have a baseline examination within 2 to 3 years from the time of diagnosis.