Nearly 26 million Americans have diabetes, including types 1 and 2.1 All people with diabetes are at increased risk of complications over time, including a cluster of eye disorders such as cataracts, glaucoma and diabetic retinopathy.
Diabetic retinopathy is the most common eye disorder in people with diabetes and is a primary cause of blindness in adults. People with both type 1 and type 2 diabetes are at risk for diabetic retinopathy and as many as 40% to 45% of patients diagnosed with diabetes have some degree of diabetic retinopathy.2 In fact, during the first two decades of illness, nearly all patients with type 1 diabetes, and more than 60% of patients with type 2 diabetes will have retinopathy.3
Retinopathy is a condition caused by damage to the small fragile blood vessels in the retina. Like many progressive disorders, diabetic retinopathy can be classified into subcategories ranging from the milder nonproliferative diabetic retinopathy to the more serious proliferative diabetic retinopathy depending on the extent of blood vessel damage.
Diabetic retinopathy can result in blocked, swollen and leaky retinal blood vessels. New vessels may grow on the retina itself and in vitreous, the gel-like fluid in the back of the eye. Over time, damage from broken blood vessels leads to bleeding in the eye causing blurry vision, vision loss and even blindness. Vision loss may also result from glaucoma or retinal detachment.
With diabetic retinopathy, vision impairment may also be linked to a comorbid condition known as macular edema, which occurs when fluid fills the eye’s macula causing it to swell. Macular edema is a downstream consequence of diabetic retinopathy, most typically detected in the later stages of the disease, but can be present at any stage. About half of all people with diabetic retinopathy also have macular edema.2
Though as many 24,000 people with diabetes lose their vision each year,4 diabetic retinopathy does not necessarily lead to vision loss and blindness. Even in proliferative disease, treatment and follow-up can reduce the risk of permanent vision loss by 95%.2
It is important to remember, however, that these high treatment success rates do not mean a permanent cure. Continuing follow-up, which may include additional treatment, may be necessary to protect vision over the course of a diabetic patient’s life.
Diabetic retinopathy presents with relatively no symptoms in its earliest stages. Some signs of more advanced disease include6:
- Blurred or partially blocked vision
- Seeing “floaters,” which are small spots of blood circulating across the retina
- A dark or blind spot in the central vision
- Poor night vision
Treatment should be sought to diagnose the condition and to prevent hemorrhage and severe vision loss.
Screening and diagnosis
Individuals with diabetes should have a comprehensive dilated eye exams annually to check for signs of developing retinopathy. An ophthalmologist or optometrist who is knowledgeable and experienced in diagnosing the presence of diabetic retinopathy and is aware of its management should perform examinations.
The American Diabetes Association (ADA) recommends eye exams for adults and children ages 10 years or older with type 1 diabetes within the first five years after diabetes onset.6 For those with type 2 diabetes, an exam should be given soon after the diagnosis of diabetes is made.
Annual eye exams are recommended thereafter for most patients with diabetes. The ADA suggests that after normal eye exams screening may be performed less frequently, such as every two to three years. Similarly, if the eye exams show progressing retinopathy more frequent eye exams may be necessary.