Think of a retinal photograph as a picture of your front door, an optomap as a picture of the front of your house, and OCT as what's behind the front door. The drawback is that it can only do so for a small area. OCT shows all the layers behind the surface of the retina. Sometimes we need to know what's below the surface. A picture is extremely useful, but can only show the surface. An optomap gives a much bigger, wider picture. How does OCT differ from a photograph or ultrawide field image?Ī retinal photograph gives a picture of a small area of the inside of the back of the eye. It performs the same function as the film in a camera or sensor in a digital camera. The retina is the light-sensitive tissue lining the back of the eye. These measurements help with early detection, diagnosis and treatment of retinal diseases, including age-related macular degeneration and diabetic eye disease, among others. Each of the retina’s distinctive layers can be seen, allowing us to map and measure their thickness. Amazingly, the resolution is similar to that of a microscope. For our purposes in diabetes we are most interested in the retina. Optical coherence tomography (OCT) is a non-invasive imaging test that uses light waves to take cross-sectional pictures of parts of the eye (retinal, optic nerve, anterior chamber, cornea).
