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What is Optical Coherence Tomography? And do I need it?

As we have installed Optical Coherence Tomography (OCT) equipment into our Lytham practice 12 months ago, we felt it would probably be a good idea to explain what it does.

Mike Broadhurst, our director and optometrist at Boptom, has kindly agreed to answer all our questions about this incredible piece of equipment.

In simple terms, what exactly is OCT?

This equipment is essentially the equivalent of an MRI scan of the eye, not only are we able to see the macula but we can also look at many areas of the retina in great detail.


We want to see the macula and disc in great detail. The macula is the small satellite-dish part of the retina that receives most of our light. The optic disc is important to view to ensure the nerve fibres entering the eye are not impaired with regard to our ability to see. This is particularly important for patients who either have or are at risk of developing glaucoma.

The good thing about this system is we can can see a true appearance of the macula as this provides us with three dimensional views of these areas.

The equipment can also detect drusen, which are tiny white accumulations within the eye. Although these are quite normal in adults over 40, it is when there are larger drusen present that we need to monitor this as it could potentially lead to the development of age-related macula degeneration.

In more extreme cases, the OCT helps to determine whether a patient has wet macula degeneration, where some blood vessels bleed, which may benefit from injections into the eye to stop this and to help retain as much vision as possible.

The OCT is also good for assessing any potential macula holes in the peripheral retina, which may be brought about by such things as vitreous detachments. This occurs where the ‘jelly’ pulls away from the retinal surface, potentially damaging this and leaving a hole or tear.

How does the OCT differ from a normal fundus camera?

This instrument provides us with a fully-comprehensive look at the eye in three dimensions.A normal fundus camera only provides a two dimensional ‘flat’ image of the surface of the retina.

Using the OCT, I can I can view any image taken with up to 150 different ‘layers’ available to view. It allows me to see the optic nerve head where all the nerves are delivered to the eye, or any other area that I wish to focus upon.

What are floaters and flashing lights, what does the OCT do for people who suffer from these or risk having these?

Floaters are generally described as ‘small black dots’ or ‘cobweb like specs’ moving across the vision. These are malformations in the jelly that fills the space in the middle of the eye. This debris casts shadows onto the retina.

When these floaters first appear, it may be due to the jelly ‘parting’ from the retina, and if flashing lights are visible too, it important to have these investigated urgently to rule out any possible retinal tear or hole.

I don’t seem to have any eye-related conditions, is there any need for me to take the test?

The scan can detect minor changes in the retina allowing us to build up an invaluable ongoing record of health and condition of patients eyes over the years.

How long does it take and when do I get to know the results?

The test is non-invasive and painless and takes only 2-3 minutes. All results are usually discussed immediately. For more information on the OCT equipment please do not hesitate to get into contact. Drop us an email at


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