DIABETIC RETINOPATHY





Jorge A . Montes, MD, FACS



Diabetes affects many organs in the body, most notably the kidneys, lower extremities, and the eyes. Since it is the leading cause of blindness in the US, we need to understand its causes and risk factors. Evidence shows that not everyone with diabetes has these organs affected. So what causes diabetic retinopathy to present in the eye?


RISK FACTORS

A chronically sustained elevation in blood sugar will increase the A1c level, a level of which every person with diabetes should know. Slight elevations in this number can still cause diabetic retinopathy to present, although it may take longer. High elevations in A1c levels can cause diabetic retinopathy to present quickly. It is crucial to know the A1c level. Other factors, such as high blood pressure, high cholesterol, and pregnancy, are risk factors for developing diabetic retinopathy. Controlling these risk factors is essential to prevent the manifestation of diabetic retinopathy.


WHAT HAPPENS IN THE EYE WHEN DIABETIC RETINOPATHY PRESENTS

Experts believe that sustained elevation of blood sugars and the presence of the risk mentioned above lead to damage to the small capillaries in the retinal circulation or the retinal blood flow. Low blood flow leads to the production of a hormone called Vascular Endothelial Growth Factor, or VEGF. VEGF stimulates the production of new blood vessels. Unfortunately, these new blood vessels do not help improve blood flow and, ultimately, break and leak blood and fluid into the eye. In trying to help (growing new blood vessels to bring more oxygen to the eye), the eye does more harm than good. Overall, in a simple explanation, the problem lies with damaged capillaries and increasing levels of VEGF. Now we can understand the treatment options available.



TREATMENT

With proper control of A1c, blood pressure, and blood cholesterol, we can mitigate the chances that diabetic retinopathy presents in the eye. Management of these risk factors should be as per the Primary Care Physician or Endocrinologist. However, sometimes, managing these risk factors may not be enough to thwart off the diabetic retinopathy.


We focus the treatment based on two notable exam findings, and each can have subcategories:

1) The amount of blood vessel growth and

2) The amount of swelling in the most crucial part of the back of the eye - the Macula.


Not all diabetic retinopathy needs to will be treated, and most will only need monitoring. All patients with diabetic retinopathy should focus on improving their A1c levels and all other risk factors.


Options for treatment include:

  • • Injections in the eye (anti-VEGFs or steroids)
  • • Lasers called Focal Laser or Pan-Retinal Photocoagulation (PRP)
  • • Surgery The damage caused by diabetic retinopathy is not reversible.


The treatments above try to slow the progression of the disease. The goal of all three of these treatments is to decrease VEGF production, decrease inflammation and swelling, and make it harder for the growth of blood vessels to occur. Also, surgery removes the gel of the eye called the vitreous body. The vitreous body can act as a sponge for VEGF and a scaffold for new blood vessels to grow on. So in severe cases, the vitreous body is surgically removed.


The ophthalmologist will decide, based on the examination, which combination of these will be needed.