Diabetic retinopathy is a leading cause of vision loss and can lead to blindness.
Diabetes is a chronic disease that affects more than 420 million people worldwide. If left uncontrolled, diabetes can lead to serious damage to many of the body’s systems, including the eyes. These diabetic eye complications can include cataracts, glaucoma and diabetic retinopathy.
Usually affecting both eyes, it occurs when diabetes damages the tiny blood vessels on the retina, the light-sensitive tissue located on the back inner-wall of the eye.
Eye doctors commonly separate Diabetic Retinopathy into 2 stages: Non-proliferative Diabetic Retinopathy (NPDR) and Proliferative Diabetic Retinopathy (PDR).
In NPDR, the earliest stage of diabetic retinopathy, microaneurysms occur. They are small areas of balloon-like swelling in the tiny blood vessels that nourish the retina. As they increase in number, they tend to cluster and leak fluid into the complex retinal layers.
As the disease progresses, the retinal blood vessels may become irregularly shaped, dilated and leaky. Small hemorrhages may occur and discrete whitish-yellow fat residue can accumulate as a result of the leakage.
The damaged blood vessels can also lose their ability to transport blood, depriving areas of the retina of their nourishing blood and oxygen supply.
Sometimes, the macula, the part of the retina that provides sharp, central vision, begins to swell, causing diabetic macular edema, or DME — a vision-blurring condition. DME is the most common cause of vision loss in patients with diabetic retinopathy and it requires treatment.
Common treatments for these early-to-mid-stage diabetic complications include: eye drops, laser photocoagulation and painless injections of medications into the eye.
As more and more blood vessels are damaged and blocked, the retina becomes stressed and sends out signals for oxygen and nourishment, triggering the growth of new blood vessels. This is called neovascularization, the hallmark of the advanced stage – Proliferative Diabetic Retinopathy.
These new blood vessels are weak and fragile and have thin, delicate walls. They will often bleed into the vitreous — the transparent gel-like tissue filling the inside of the eyeball.
Blood in the vitreous causes symptoms ranging from barely noticeable, to complete vision loss in the affected eye. Common symptoms of a vitreous hemorrhage include: small, dark floating spots in the vision; a reddish tint; or random-shaped darkened sections of the vision.
Common treatments for PDR include: heavy laser photocoagulation and intravitreal medication injections.
In the severe, uncontrolled stage of PDR, scar tissue, as a result of neovascularization and bleeding, can contract, causing the retina to pull away from underlying tissue – this is called Retinal Detachment and can lead to permanent vision loss. This type of retinal detachment must be repaired surgically.
Diabetic retinopathy can’t always be controlled. However, good blood sugar and blood pressure control, regular eye exams and early intervention for vision problems will decrease the risk of severe vision loss.