Optical Coherence Tomography (OCT)

As of November this year we will be acquiring a special piece of equipment called an Optical Coherence Tomographer (OCT). This machine is capable of providing us with a very high resolution three-dimensional digital scan of the inside of your eye, much like an MRI scanner at the hospital.

The scan the OCT provides is so detailed that it can pick up the very earliest signs of glaucoma damage to the microscopic nerve fibres at the back of your eye. This makes it possible to pick up signs of glaucoma before it affects your sight, and indeed before it is detectable using more traditional techniques. This makes OCT the definitive screening tool currently available for this condition.

The OCT also provides us with highly useful information about other parts of your eye. For example, it is capable of detecting small areas of swelling that can occur at the back of your eye in macular degeneration, as well as any small retinal holes, tears or cysts that may be present.

We recommend OCT for all of our patients as part of an ongoing ocular health assessment, but especially for those people who are most at risk of eye conditions such as glaucoma and macular degeneration (e.g. individuals with a family history of eye disease, and/or over the age of 40). As one would expect, performing an OCT scan goes above and beyond what is covered by the NHS for a standard sight test. As a result there is an additional charge for having this procedure done. Feel free to ask your optometrist about OCT at your next appointment with us.

 

What can the scan check for?

Glaucoma

The scan the OCT provides is so detailed that it can pick up the very earliest signs of glaucoma damage to the microscopic nerve fibres at the back of your eye. This makes it possible to pick up signs of glaucoma before it affects your sight, and indeed before it is detectable using more traditional techniques. This makes OCT the definitive screening tool currently available for this condition.

 

Vitreous Detachments

Vitreomacular traction can clearly be diagnosed through OCT providing invaluable information as to the current relationship between the vitreous and the retinal surface. As we get older the vitreous, the jelly that takes up the space in your eyeball, can change. It becomes less firm and can move away from the back of the eye towards the centre, in some case parts do not detach and cause 'pulling' of the retinal surface. The danger of a Vitreous detachment is that there is no pain and your eyesight will seem unchanged but the back of your eye may be being damaged.

Macular Holes

A Macular hole is a small hole in the macular, the macula is the part of the retina which is responsible for our sharp, detailed, central vision. This is the vision we use when looking directly at things, when reading, sewing or using a computer. There are many causes of Macular holes, one is via the advance of a Vireous detachment, as the vitreous pulls away from the back of the eye sometimes it does not 'let go' and eventually tears the retina, leaving a hole. Extreme exposure to sunlight (i.e. staring at an eclipse) can also cause a hole to develop.
 

Macular Degeneration

Macular degeneration causes the gradual breakdown of the macualr (the central portion of the eye). OCT can not only identitfy this condition and its type (there are two types, Wet and Dru) but also monitor its progress, for example if you are undergoing treatment for such a condition. Unfortunately the risk of developing macular degeneration increases with age, and is the most common cause of vision loss in individuals over the age of fifty.