What is an OCT?
Ocular Coherence Tomography (OCT) is an advanced eye scan that can be used on people of all ages. Similar to ultrasound, OCT uses light rather than sound waves to illustrate the different layers which make up the back of your eye.
It is completely safe and non-invasive. The scan takes less than a minute and requires no drops or contact with the eye. When an optometrist looks into your eye they can usually only see the retinal surface; OCT gives us an image of the many layers of the retina so we can look beyond the surface for any changes. For a number of years we have been able to photograph the back of your eye making the record of your ocular health much more accurate. With the new 3D scan we still have the photograph but now we also have a three dimensional cross section of the back of your eye. We can also use it to get a 3D image of the structures at the front of the eye, for example to measure the thickness of your cornea.
Why have OCT scans?
Being able to see ‘through’ the retina means we can pick up changes in your eyes that wouldn’t normally be seen during a routine eye examination. Optometrists are highly trained in detecting eye disease as well as a number of general health problems; the OCT will allow us to screen for changes and detect them much earlier than usual. Some of the things it will allow us to do:
- See very early changes in the retinal nerves, leading to very early detection and prevention of glaucoma
- Screen for early stage macula degeneration before it becomes visible on the surface
- Monitor moles or ‘naevi’ in the retina (like moles on the skin, these are surprisingly common and can occasionally become malignant so should be closely monitored)
- Find small holes and distortions in the macula (the centre of the retina) which can help explain blurred vision and can often be treated.
- Detect fluid under the retina in diabetes and other vascular disease
- Differentiate between retinal detachment and posterior vitreous detachment.
Who should have an OCT?
OCT is recommended for everyone over 50 as a screening tool. It never hurts to be given the all-clear!
It is particularly advised for people with a family history of glaucoma or macula degeneration, diabetics or people with hypertension and for those noticing any unusual change in their vision.
Building up a series of images over several visits can be the first clue that changes are happening in your eyes, and the OCT software allows us to analyse and compare your results from one visit to the next.