Diabetic Retinopathy

Diabetic retinopathy is a long-term complication of diabetes that affects the eyes. The World Health Organization (WHO) estimates that diabetic retinopathy is responsible for 4 percent of the 45 million cases of blindness throughout the world. It is caused by a damage to the blood vessels of the retina. The blood vessels of the retina are damaged due to chronically high amounts of sugar in the blood. The retinal damage affects and distorts a person's vision. The retina is the part of the eye where photoreceptors, which are specialized cells that are necessary to have a good vision, are located.

This medical condition progresses gradually, having no signs and symptoms at its early stages. As the disease progresses, mild to moderate vision problems occur. Eventually, it can result in blindness.

Diabetic retinopathy can affect anyone of any age. However, this eye disease is commonly associated with people who have diabetes, regardless if it is type 1 or type 2. The longer you have diabetes, especially diabetes with uncontrolled levels of sugar in the blood, the more likely you will develop diabetic retinopathy. It usually affects both of the eyes. Other risk factors of diabetic retinopathy include high blood pressure, high levels of cholesterol, pregnancy, cigarette smoking, and alcohol abuse.

Research indicates that over 90 percent of the new cases of diabetic retinopathy could be reduced through vigilant monitoring as well as proper treatment of the eyes. Having regular and comprehensive eye examinations, controlled blood glucose levels, and maintaining a normal blood pressure can go a long way in reducing the risks of developing diabetic retinopathy. People who have diabetes should have their eyes checked from the time they have their diabetes diagnosed and from then on, every two years.

Types of Diabetic Retinopathy

There are two types of diabetic retinopathy:

• Non-proliferative diabetic retinopathy (NDPR) – also known as the "early diabetic retinopathy", is characterized by a damage to the blood vessels in the retina, but new blood vessels aren’t growing. Non-proliferative diabetic retinopathy is the earliest stage of diabetic retinopathy.
• Proliferative diabetic retinopathy (PDR) – also known as the "advanced diabetic retinopathy", is characterized by a severe damage of the blood vessels in the retina, accompanied by the proliferation of new blood vessels, which are fragile and may easily bleed causing loss of vision. PDR can cause a more severe vision loss because it can affect both the central and peripheral visions.

Risk Factors of Diabetic Retinopathy

Anyone with type 1 or type 2 diabetes is at risk of developing diabetic retinopathy. If you are diabetic, then you are at greater risk if:

• you have had diabetes for a long time
• you have a poorly managed diabetes
• you have hypertension (high blood pressure)
• you have high cholesterol
• you are pregnant
• you are of Asian, Afro-Caribbean, Native American, or Hispanic descent

Signs and Symptoms of Diabetic Retinopathy

In its early stages, diabetic retinopathy has no signs and symptoms. There is no pain and vision may remain unaffected until the disease becomes severe. However, as the disease progresses and the damage to the blood vessels of the retina continues, the signs and symptoms gradually appear. The characteristic signs and symptoms of diabetic retinopathy are:

• blurred vision
• dark spots in the vision
• impaired color vision
• fluctuating vision
• double vision
• cataracts
• corneal abnormalities due to corneal abrasions
• dark or even empty areas in the vision
• blindness
• increased sensitivity to glare and a difficulty in seeing at night

An early diagnosis of diabetic retinopathy is essential for the preservation of one's vision. Do not wait for the symptoms to show. Ensure that you get a comprehensive dilated eye exam at least once a year.

How is diabetic retinopathy diagnosed?

• Eye Dilation - is an eye exam used for the diagnosis of diabetic retinopathy. Eye drops that dilate the pupils are placed in the eyes to help your doctor visualize better the inside of your eyes. Eye dilation allows doctors to look inside the retina and check for the following abnormalities:
  • changes to blood vessels
  • damage to nerve tissues
  • leaking of blood vessels
  • swelling of the macula
  • changes in the lens
• Tonometry - is an eye test that measures the fluid pressure inside your eyes.
• Visual acuity test - this test uses an eye chart that helps in assessing a person's ability to see details or symbols from a distance.
• Other examinations - are available to help diagnose diabetic retinopathy. They include optic coherence tomography and fluorescein angiography. Fluorescein angiography is used to look for damaged or leaky vessels and when severe diabetic retinopathy is suspected.

How is diabetic retinopathy treated?

If left untreated, diabetic retinopathy will lead to various complications until a total loss of vision occurs. The complications of diabetic retinopathy include vitreous hemorrhage, retinal detachment, glaucoma, and eventually, a total blindness will occur.

Treatment always depends on the type of diabetic retinopathy as well as its severity. The aim of the treatment is to slow down or stop the progression of the retina's blood vessel damage and to prevent the proliferation of new blood vessels.

Mild to moderate diabetic retinopathy sometimes do not require treatment. Regular eye examinations will help your doctor track the progression of your eye health. However, advanced cases of diabetic retinopathy do require treatment. Treatment options include scatter laser treatment, focal laser treatment, and vitrectomy. The aim of laser surgery is to seal the leaking blood vessels. Your optometrist may also inject a medication into your eye to decrease inflammation and to stop the formation of new blood vessels.

Vitreous hemorrhage occurs due to a vitreous detachment from the retina, which severely reduces one's vision. In such cases, a vitrectomy (removal of the vitreous) is the choice of treatment. A vitrectomy is done only after other forms of treatment have been tried or when there is a failure to control the progression of disease or progression of visual loss.

Diabetic patients are thrice as likely to develop eye problems compared to non-diabetic patients. The best treatment option for diabetic retinopathy is by preventing its development or progression, which can be achieved by maintaining a good control of blood sugar levels, taking the prescribed medications, and having regular eye checkups. Moreover, having a constant communication with your doctor is immensely vital because health care professionals are the ones who can help and guide you in managing your condition.