An Optical Coherence Tomography (OCT) test may sound like a mouthful, but the procedure itself is a little more straightforward. An OCT is a non-invasive test that allows your optometrist to take cross-section pictures of your retina using light waves.
An OCT employs a LASER (with no radiation) to obtain high-resolution images of the layers of the eye’s retina and the optic nerve. Your eye doctor can use these colour-coded images to scan for irregularities in the optic nerve, and accurately measure the thickness of the retina.The clear, 3D images provided by an OCT test can help patients visualize any problems they may be experiencing with their eyesight.
An OCT scan provides a clear map to help your eye doctor find areas of the eye with abnormalities or early damage. It’s vital to catch eye conditions in the early stages to prevent damage to a patient’s vision.
Diagnosing vision problems in the early stages can allow your optometrist to provide preventative treatment for conditions including glaucoma, and retinal diseases like Age-related macular degeneration (AMD).
OCT has been described as a safe, non-invasive ultrasound for your eye, using light instead of sound waves to create a map of the retina and optic nerve. Guided waves of light provide a precise 3D image of the eye’s structure, without making direct contact with the patient’s eyes.
Because OCT relies on waves of light, it is not effective for any condition that affects how light passes through the eye, including cataracts.
Patients at risk of developing glaucoma can benefit from an OCT scan, as the images can help evaluate the anterior angle of the eye. The anterior angle is an essential part of the eyes’ anatomy that operates as the drainage channel for fluid.
When the drainage channel is not working correctly, it can lead to an increase in eye pressure. This pressure causes damage to the optic nerve and can result in vision loss.
An OCT provides your optometrist with detailed, multi-level images of the anterior angle. These images can help determine severity, and distinguish between types of glaucoma, such as:
Your optometrist may use eye drops to dilate your pupils, allowing for a more accessible retinal examination. Once your pupils are dilated, you will be asked to sit in front of the OCT machine with your head resting on the support to encourage stillness.
Once in the proper position, your eye doctor will advise you to look into the device’s lens, which contains a blinking target. At this point, the machine scans your eye with no physical contact. The OCT test is completed in approximately 5 to 10 seconds.
If your optometrist used dilating eye drops before the exam, your eyes might be sensitive to light for a few hours afterward.
If you have questions about OCT tests or would like to book an appointment, do not hesitate to reach out to our experienced team at Gupta Eye Hospital.