This article explains how OCT works and its uses in diagnosing conditions of the eye.
Thinkstock / Getty Images
Optical Coherence Tomography During an Eye Exam
Optical coherence tomography is a way for optometrists and ophthalmologists to image the back of the eye including themacula,optic nerve,retina, andchoroid(a thin layer of tissue that is part of the middle layer of the wall of the eye).
During an eye examination, optometrists and ophthalmologists can view the back of the eye and its anatomy. However, sometimes they need more detail or need to inspect details right below the surface, which is difficult to view with standard techniques. Some describe OCT as an “optical ultrasound” because it provides cross-sectional images.
The detail that can be visualized with an OCT is at such high resolution that doctors can see much finer details. The resolution of OCT is finer than 10 microns (10 millionths of a meter), which is better than MRI or ultrasound.
As a result, OCT not only provides much greater detail than other methods, but it also shows exactly which layer of the retina is accumulating fluid causing edema or swelling. OCT can also be used to track the healing or resolution of that swelling.
OCT images to approximately 2 to 3 millimeters below the surface of the tissue. Images are obtained clearly through a transparent window, such as the cornea. The light that is emitted into the eye is safe, so no damage will occur.
What To Expect During Optical Coherence Tomography
OCT takes only a few minutes to perform. With most OCT machines, the process is as follows:
If your pupils are very small or if the doctor wants an image of a very specific area, your pupils may be dilated with medicated eye drops.
What Can an OCT Scan Detect?
OCT is used in the evaluation of many eye conditions, including:
Central Retinal Artery Occlusion (CRAO): What to Know
Summary
3 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Aumann S, Donner S, Fischer J, Müller F.Optical coherence tomography (OCT): principle and technical realization. In: Bille JF, ed.High Resolution Imaging in Microscopy and Ophthalmology. Cham, Switzerland. Springer International Publishing; 2019:59-85. doi:10.1007/978-3-030-16638-0_3Chopra R, Wagner SK, Keane PA.Optical coherence tomography in the 2020s—outside the eye clinic.Eye. 2021;35(1):236-243. doi:10.1038/s41433-020-01263-6American Academy of Ophthalmology.What is optical coherence tomography?
3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Aumann S, Donner S, Fischer J, Müller F.Optical coherence tomography (OCT): principle and technical realization. In: Bille JF, ed.High Resolution Imaging in Microscopy and Ophthalmology. Cham, Switzerland. Springer International Publishing; 2019:59-85. doi:10.1007/978-3-030-16638-0_3Chopra R, Wagner SK, Keane PA.Optical coherence tomography in the 2020s—outside the eye clinic.Eye. 2021;35(1):236-243. doi:10.1038/s41433-020-01263-6American Academy of Ophthalmology.What is optical coherence tomography?
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Aumann S, Donner S, Fischer J, Müller F.Optical coherence tomography (OCT): principle and technical realization. In: Bille JF, ed.High Resolution Imaging in Microscopy and Ophthalmology. Cham, Switzerland. Springer International Publishing; 2019:59-85. doi:10.1007/978-3-030-16638-0_3Chopra R, Wagner SK, Keane PA.Optical coherence tomography in the 2020s—outside the eye clinic.Eye. 2021;35(1):236-243. doi:10.1038/s41433-020-01263-6American Academy of Ophthalmology.What is optical coherence tomography?
Aumann S, Donner S, Fischer J, Müller F.Optical coherence tomography (OCT): principle and technical realization. In: Bille JF, ed.High Resolution Imaging in Microscopy and Ophthalmology. Cham, Switzerland. Springer International Publishing; 2019:59-85. doi:10.1007/978-3-030-16638-0_3
Chopra R, Wagner SK, Keane PA.Optical coherence tomography in the 2020s—outside the eye clinic.Eye. 2021;35(1):236-243. doi:10.1038/s41433-020-01263-6
American Academy of Ophthalmology.What is optical coherence tomography?
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
