Optical Coherence Tomography

What is it?

Optical Coherence Tomography (OCT) is equivalent to an optical ultrasound. It takes a cross-section picture of your retina, the light-sensitive tissue lining at the back of the eye. It is an established and accurate technique to view the inside of a patients eye non invasively. The equipment reflects light waves into the patients eye and measures the distance it has travelled, collaborating the information to build up an image of the of the eye. Areas of the eye which reflect a lot of light back will create greater interference than areas that don't.
OCT Machine and image of Retina

Put simply …if you imagine looking down on the top of a birthday cake all we see with a digital camera or a ophthalmoscope is the icing on the top of the cake. With 3D OCT it is like lifting a slice out of the cake and examining all the layers.

The Retina

The retina is made up of distinctive layers (see images) which the OCT can map and measure the thickness of. This allows optometrists to view the overall health of the eye, as well as detect and early diagnose diseases, such as multiple sclerosis, diabetic eye disease and macular degeneration.

Healthy Retina
Age Related Macular Degeneration
Vitreo Macular Traction

Why did we invest in it?

10 years ago the only practical way to examine the back of the eye was to use an ophthalmoscope and the view was limited. Then in 2003 we bought our first digital fundus camera, which takes images of the back of the eye and stores them on computer. The advantages over an ophthalmoscope were a better, wider image and a permanent record to compare the fine detail with the next time.

Our new 3D OCT not only takes more detailed, better images but also takes individual scans of the back of the eye, which are effectively cross-sections through the retina and show up the structures of the back of the eye in incredibly fine detail. It puts all the individual scans together to produce a three dimensional image of the retina which allows us to see and understand much better the very fine changes which can be indications of something going amiss. Thus allowing earlier, often more effective, treatment.

How long does it take and will it hurt?

In some cases your optometrist will put pupil dilating eye drops in to your eyes in order to widen your pupils before the OCT examination. Once your pupils have dilated they will seat you in front of the OCT machine and ask you to rest your chin on to a support to keep your head motionless. The machine will then scan your eye which can take up to 15 minutes to complete. It is non invasive and only takes a few minutes for the scanner to take images of the back of the eye but a little longer for the optometrist to interpret and explain what has been found.

Is it free?

OCT scans are not covered by the eye examination funded by the NHS and a separate charge has to be made for this service.

Will I benefit from this equipment?

We would encourage every patient to have regular scans, because it shows us in detail what your eye is like now and so it will help us to spot small but significant changes in the future. This is particularly useful for patients worried about Glaucoma, Macular Degeneration, and ‘flashes and floaters’.

If you would like to make an appointment for an OCT call us on 01938 553 180