November is Diabetes Eye Disease Awareness Month, turning our attention to the risks for diabetic retinopathy, a sight-threatening complication of diabetes. Diabetic retinopathy occurs when high blood sugar levels damage small blood vessels in the retina. The vessels leak, causing retinal tissue to swell, affecting vision. There are two types of diabetic retinopathy, non-proliferative and proliferative. Non-proliferative diabetic retinopathy (NPDR) is the early stage of the disease in which blood vessels in the retina are weakened and may leak fluid into the retina leading to swelling of the macula. Proliferative diabetic retinopathy (PDR) is the more advanced form of the disease in which damage to blood vessels deprives the retina of oxygen. As a result, new blood vessels can begin to grow in the retina. The new blood vessels are fragile and may leak blood into the vitreous, impairing vision.
Diabetic retinopathy can be diagnosed through a dilated eye exam by an optometrist or ophthalmologist. In April 2018, however, the FDA approved a device that uses AI to screen for diabetic retinopathy and can be used by health care professionals outside of eyecare. The IDx-DR uses an AI algorithm to analyze images taken with a Topcon NW400 retinal camera and uploaded to a cloud server. The software then provides one of two results: 1. “More than mild diabetic retinopathy detected: refer to an eyecare professional” or 2. “Negative for more than mild diabetic retinopathy; rescreen in 12 months.” It is important to note that this is a screening tool, and patients with detected retinopathy must be referred to an eyecare professional for further evaluation and treatment.
In the study of 900 patients the FDA used to evaluate data, 76 percent of patients could be screened without dilation, and IDx-DR correctly identified more than mild diabetic retinopathy 87.4 percent of the time, while correctly identifying those who did not have more than mild diabetic retinopathy 89.5 percent of the time. Some health clinics have begun using the device, and this year the American Diabetes Association (ADA) included AI in its Standards of Medical Care in Diabetes stating, “systems... authorized for use by the FDA represent an alternative to traditional screening approaches.”
The IDx-DR is not intended to replace a regular comprehensive eye exam by an optometrist or ophthalmologist. You can learn about the role of contact lenses in diabetes treatment with our CE, “The Mature Contact Lens Patient” at 2020mag.com.
• Linda Conlin
Pro to Pro Managing Editor