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OCT Scans

What is an OCT scan?

An optical coherence tomography scan (commonly referred to as an OCT scan) allows us to see what’s going on beneath the surface of the eye which helps us to view the health of your eyes in greater detail.

Using the 2D digital retinal photography (fundus camera) provides only a view of the surface of the back of eye, but the 3D image produced from an OCT scan allows us to see all the layers.  Our opticians can therefore map out and measure the thickness of these layers to get an even clearer idea of your eye health.

OCT scans can help detect sight-threatening eye conditions earlier. In fact, glaucoma can be detected up to four years earlier.

How is an OCT scan different to an eye test?

OCT is performed separately to an eye test. An eye test checks your eye health as well as how well you can see, but an OCT scan takes this a step further, allowing us to look even deeper into your eyes and the structures within it.

Essentially, an OCT scan gives us a clearer idea of your eye health when testing your eyes.

Why do I need an OCT scan?

OCT scans are recommended for people aged 25 or over, who want to know more about their eye health, or those who may already have diabetes, glaucoma, or have a family member with a history of eye disease.

Even if your vision and eye health are perfectly fine, we still recommend an OCT scan with every eye test. It’s really useful for us to have a baseline image on file, so we can monitor any changes over time. It’s the same as when we take an image of the back of your eye with digital retinal photography.

So the next time you come in for an eye test, we can compare your images from your last visit as well as comparing measurements to averages and might spot even the tiniest change in the eye’s structures. This could help indicate the early signs of an eye health condition like glaucoma, diabetic retinopathy and macular degeneration before you have any symptoms.

Therefore, conditions like these can be managed before they get worse and could help prevent potential sight loss. That’s a pretty good result for just a quick scan.

How much does an OCT scan cost?

Because OCT scans are separate to your eye test, an additional charge applies so please speak to us about this when booking your appointment.

Does it take longer than a regular eye test?

An OCT scan takes a matter of seconds and our optician will go through the results with you during your eye examination.

What is an OCT scan used for and what conditions can it help to detect?

OCT scanning is great at confirming that your eyes are healthy and can be repeated over time for comparison. This makes it particularly useful for detecting potentially sight threatening conditions that generally don’t have any symptoms until they start to have an impact on your vision.

Many of these conditions form at the very back of the eye, and OCT allows us to identify subtle changes over time, such as changes in the vitreous (the jelly-like substance that fills the eye), retina (the light-sensitive layer at the back of the eye), macula (an area at the centre of the retina responsible for our central vision) and the optic nerve (transmits light impulses to the brain to produce the images we see).

These include:

  • Glaucoma
  • Diabetic retinopathy
  • Detached retina
  • Age-related macular degeneration
  • Macular hole

In fact, an OCT scan can help to detect glaucoma up to four years earlier than traditional methods.

How does optical coherence
tomography work?

Taking just a few seconds, an OCT scan uses light to take over 1,000 images of the back of your eye and beyond, looking right back to the optic nerve.

A layered image is created that gives us an incredibly accurate picture of your eye and its structures, allowing us to check your eye health. The images will then be stored so we can note changes over time.

I have a diabetic check annually;
do I still need an OCT scan?

Yes – while both the diabetic screening check and OCT involve taking images of the back of the eye, there are significant differences.

Diabetic checks involve a fundus picture – this is an image of the surface of the back of the eye (the retina) also known as digital retinal photography.

OCT images allow us to look at the many layers beneath the surface of the retina, which helps us to spot changes to eye health earlier than just looking at the surface.

OCT scans also help in the detection of a range of other eye problems, not just those that are linked to diabetes.

Traditional Fundus Test Image

Traditional Fundus Test Image

OCT Scan Image

OCT Scan Image


Does it hurt?

Not at all – it’s a quick, painless procedure. Just like having a photo taken.

I’m quite young, is this for older people?

OCT scans are recommended for anyone aged 25 or older. It’s really helpful for your optician to take readings and track them every time you come in and see us in order to best safeguard your eye health.

I have my eyes checked at the hospital – should I still have this?

Yes – as well as checking for a range of eye conditions that may not be under review at the hospital, it will provide an up to date appraisal of your eye health. Your optician does not usually have access to the results from your hospital examinations and the scan will give a more rounded analysis of your eye health.

Is it like having an MRI scan?

No, it’s very different from having an MRI. It’s more like having a photograph taken of your eye, you simply sit in a chair and look into the OCT device for a matter of seconds. You don’t have to lie down like an MRI scan.

Are there any OCT eye test side effects?

None. OCT uses a completely safe laser light source, so there are no side effects or risks associated with an OCT procedure.