Diabetic Retinopathy

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Diabetic Retinopathy

What Is Diabetic Retinopathy?

Diabetic retinopathy is one of several eye conditions that patients with type 1 or type 2 diabetes can develop. While many patients with diabetic retinopathy experience only minor symptoms, the condition can worsen over time, resulting in permanent vision loss. However, with proper blood sugar management and regular visits/treatments with a retina specialist, patients with diabetic retinopathy can retain their vision.

Diabetes and the Retina

Diabetic retinopathy is caused by high levels of sugar in the blood. In normal quantities, blood sugar, also known as glucose, is the body’s primary source of energy, powering every cell of the body. In excessive quantities, blood sugar can cause a wide range of metabolic problems, affecting nearly every bodily system.

One of the ways that high blood sugar harms the body is that it damages the structural integrity of blood vessels, causing them to lose their elasticity and become more narrow. This leads to the blood vessels being unable to deliver the proper amount of blood and oxygen to various parts of the body. Diabetic retinopathy is when this damage occurs to the blood vessels contained in the retina, which is the tissue that lines the back wall of the eye.

Containing hundreds of millions of photoreceptive cells that detect light, the retina plays a critical role in our sense of vision. As light enters the eye, the retina’s cells detect and measure the light signals, transmitting them along the optic nerve to the brain’s primary visual cortex. The brain makes sense of these signals and integrates them into an image. Because the retina is such a hard-working part of the body, it requires a constant flow of oxygenated blood to fuel its function. When the blood vessels that support the retina are damaged by diabetic retinopathy, it can cause a wide range of vision issues, including permanent vision loss.

Stages of Diabetic Retinopathy

Nonproliferative Diabetic Retinopathy (NPDR)

Diabetic retinopathy is a progressive disease, which means it will become more severe over time, especially without early intervention. The earliest stage of diabetic retinopathy is known as nonproliferative diabetic retinopathy (NPDR) or background retinopathy. During this stage, damage to the retinal vascular system is low, causing small amounts of leaking fluid, retinal swelling, and retinal bleeding.

Early on, patients with NPDR generally don’t experience any noticeable changes to their vision. When they do, it’s usually because of diabetic macular edema or macular ischemia. Macular edema is when the central portion of the retina, known as the macula, begins to swell due to fluid leaking from the retinal vascular system. Macular ischemia is when the blood vessels that supply the macula with oxygenated blood become sealed off.

Both of these conditions can cause symptoms such as blurred vision, visual distortions, and decreased visual acuity. Because both of these conditions affect the macula, they only impact our sense of central vision, which is the type of vision we use to see fine details and perform complex tasks such as reading and driving. In most cases, peripheral vision (i.e. our ability to see things indirectly or “out of the corner of your eye”) remains unaffected.

Proliferative Diabetic Retinopathy (PDR)

The most advanced stage of diabetic retinopathy is known as proliferative or neovascular diabetic retinopathy. At this point of the disease, several blood vessels in the retinal vasculature have shut down, inhibiting the natural cycle of blood flow to the retina. Because the retina requires a steady supply of blood and nutrients to function properly, the body triggers a process known as neovascularization. Meaning “new blood vessels,” neovascularization refers to a process in which new blood vessels are formed. This process occurs naturally during fetal development and in response to injury. However, in the retina, neovascularization becomes pathological. The new blood vessels that formed aren’t normal and healthy, but fragile and malformed. Instead of resupplying the retina with blood, the new blood vessels leak fluid and blood. They can also cause the formation of scar tissue on the retina.

Patients with PDR are more likely to experience serious vision changes and even blindness due to several possible complications, including:

• Vitreous hemorrhage, which is when the abnormal blood vessels bleed into the vitreous humor, the clear gel-like substance that fills the center of the eye
• Tractional retinal detachment, which is when abnormal scar tissue pulls the retina from its normal position.
• Neovascular glaucoma, which is when pressure builds up in the eye due to the development of abnormal blood vessels in the drainage mechanism of the eye.

Diabetic Retinopathy Diagnosis & Testing

Diabetic retinopathy is diagnosed through a comprehensive dilated eye exam performed by an ophthalmologist. To perform this exam, the ophthalmologist first administers dilating eye drops, which help to keep your pupil from constricting when exposed to light. Using precise instruments and lenses, the ophthalmologist is able to carefully examine the inside the eye.

To confirm diabetic retinopathy, a doctor may also perform imaging exams, such as optical coherence tomography (OCT), which helps to detect the amount of fluid present in the retina, and fluorescein angiography, which is done in conjunction with a special dye to highlight the blood vessels of the eye.

Treatments for Diabetic Retinopathy

Because the effects of diabetic retinopathy can often be circumvented or controlled through proper management of blood sugar levels, preventative care is considered to be one of the most effective forms of treatment. By gaining control over your diabetes, you have a greater chance of reducing the chance of experiencing severe vision changes or vision loss. Additionally, dealing with any extenuating risk factors, such as weight, smoking, or other comorbidities (e.g. kidney disease, cardiovascular disease, high blood pressure, etc.), are often recommended as part of a preventative treatment plan.

Medical Treatment

In more severe cases of diabetic retinopathy, preventative care alone is not enough. Depending on how much blood vessel damage there is or how much the disease has progressed, more advanced treatment options may be recommended.

One of the most common treatments for diabetic retinopathy is intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) medications. Anti-VEGF medications help to reduce swelling in the retina and prevent the development of abnormal blood vessels. Laser surgery is also sometimes recommended.

Vitrectomy

In progressive cases of diabetic retinopathy, doctors sometimes recommend a surgical procedure known as a vitrectomy. A vitrectomy involves removing the gel-like fluid from the eye and replacing it with a clear fluid such as saline or silicone oil. This procedure can be performed to remove blood from a vitreous hemorrhage, remove abnormal blood vessels, and/or repair a detached retina

Preventing Vision Loss With Diabetic Retinopathy

Diabetic retinopathy has become an increasing concern over the last few decades. According to the Centers for Disease Control and Prevention (CDC), diabetes affects over 37 million people in the US, which means that approximately 1 in 10 individuals is at risk for developing diabetic retinopathy or other diabetes-related vision issues. What’s more concerning is that approximately one-fifth of people with diabetes are unaware that they have it, making them especially vulnerable to diabetic eye complications. On top of this, an additional 96 million people in the US are prediabetic, with the vast majority of them unaware of it.

Diabetic eye problems such as diabetic retinopathy can often be avoided or controlled by taking the appropriate preventative measures. One of the best ways to protect your vision and overall health is to undergo a comprehensive eye exam on a regular basis. In many cases, diabetic retinopathy is only noticeable through such an exam. When it comes to preventing vision loss from diabetic retinopathy, early detection is key.

For patients who have been diagnosed with type 1 diabetes, it’s generally recommended that they schedule a diabetic eye exam within the first five years of their diagnosis. For patients with type 2 diabetes, it’s recommended that they schedule an exam as soon as they are diagnosed. After the initial exam, patients with diabetes can expect to schedule an eye exam at least once a year.

If you haven’t been diagnosed with diabetes, it is still a good idea to schedule a comprehensive eye exam every one to three years, depending on your circumstances. If you experience any unusual changes in your vision, such as blurriness, visual distortions, eye floaters, and flashes, it’s recommended that you see a doctor right away.