How are diabetic retinopathy and DME detected?

Diabetic retinopathy and DME are detected during a comprehensive dilated eye exam that includes:

• Visual acuity testing. This eye chart test measures a person’s ability to see at various distances.
• Tonometry. This test measures pressure inside the eye.
• Pupil dilation. Drops placed on the eye’s surface dilate (widen) the pupil, allowing a physician to examine the retina and optic nerve.

Optical coherence tomography (OCT). This technique is similar to ultrasound but uses light waves instead of sound waves to capture images of tissues inside the body. OCT provides detailed images of tissues that can be penetrated by light, such as the eye.

A comprehensive dilated eye exam allows the doctor to check the retina for:

• Changes to blood vessels
• Leaking blood vessels or warning signs of leaky blood vessels, such as fatty deposits
• Swelling of the macula
• Changes in the lens
• Damage to nerve tissue

If DME or severe diabetic retinopathy is suspected, a fluorescein angiogram may be used to look for damaged or leaky blood vessels. In this test, a fluorescent dye is injected into the bloodstream, often into an arm vein. Pictures of the retinal blood vessels are taken as the dye reaches the eye.