An OCT scan, short for optical coherence tomography, creates detailed cross-sectional images of the retina. This guide explains what the scan can show, how it fits into an eye examination and how it may help identify changes before symptoms are noticed.
What is an OCT scan?
OCT stands for optical coherence tomography. An OCT scan is a quick, non-invasive eye imaging test that uses light to create cross-sectional pictures of the retina at the back of the eye. These images show layers beneath the retinal surface, giving your optometrist extra information alongside the other checks in an eye examination.
During the scan, you look into the instrument and focus on a target while it captures images. The scan is painless and does not touch the eye. Your optometrist can talk you through what the images show and compare them with previous scans when available.
What can an OCT eye scan help to identify?
An OCT scan can help an optometrist identify or monitor changes in structures such as the retina, macula and optic nerve. Depending on the images and your wider clinical assessment, OCT may be useful when looking for signs associated with:
- glaucoma and changes to the optic nerve;
- age-related macular degeneration (AMD);
- diabetic retinal or macular changes, including swelling;
- macular holes or other changes affecting the central retina.
Some eye conditions can develop before a person notices symptoms. OCT images may help reveal subtle changes and provide a baseline for comparison at later visits. A scan does not guarantee that every eye condition will be found, and an OCT result on its own is not a diagnosis. Your optometrist considers it together with your symptoms, history and other examination findings, and may recommend further tests or a referral if needed.
Is an OCT scan the same as a regular eye test?
No. An OCT scan is one imaging test that can add detail to an eye examination; it does not replace the full eye test. A sight test also assesses your vision and prescription and includes other checks chosen by the optometrist. OCT is also different from NHS diabetic eye screening, which has its own purpose and pathway. Continue attending any screening appointments you have been invited to.
Who might benefit from an OCT scan?
Your optometrist may recommend OCT based on your age, symptoms, family history, health conditions or what they see during the eye examination. It can be particularly useful for monitoring known or suspected changes over time. Even if your vision seems clear, regular eye examinations remain important because some eye problems do not cause obvious early symptoms.
Is OCT included with an eye test at Specialeyes Eyecare?
At Specialeyes Eyecare in Shepherds Bush, a free OCT scan is included with every eye test. The optometrist will explain the scan and discuss any findings with you as part of your appointment. This local service is available at our West London practice on Uxbridge Road.
To arrange an eye test with an OCT scan in Shepherds Bush, book online or contact our team. If you are searching for an OCT scan or an OCT eye test in West London, we can explain what is included before your visit.
Frequently asked questions about OCT scans
How long does an OCT scan take?
The scan itself usually takes only a short time. Your appointment may include other checks and time to discuss your results.
Can OCT find glaucoma before symptoms appear?
OCT can show structural changes that may be associated with glaucoma, sometimes before a person notices vision changes. It is one part of an assessment; diagnosis and monitoring use the full clinical picture and may require additional tests.
Do I still need my routine eye test if I have had an OCT scan?
Yes. OCT is an additional imaging test and does not replace a complete eye examination or any separate screening arranged for you.