Investigations

What is OCT? O (OCT)

Optical coherence tomography (OCT) is a non-invasive diagnostic test widely used in the field of ophthalmology. The test involves the use of light waves to map the back of the eye and generate high-resolution cross-sectional images of ocular tissues.

The exam provides information on the retina and choroid. The test is commonly used for the diagnosis of several ophthalmic conditions.

It enables the eye specialist to determine whether or not treatment is needed and is useful as a monitoring tool to assess response to treatment or onset of complications.

The procedure has been carried on for several decades and has been proven safe to use in both younger and older patients.

Before the procedure

Dilating drops will be administered to enlarge the pupils. The drops will cause the vision to become blurred. The effect of these drops will last for 4 to 6 hours. The drops can also make the eyes sensitive to bright light; patients may wish to bring a pair of sunglasses with them to protect the eyes.

During the procedure

Once the pupil is dilated, the patient will sit still in front of a camera with the chin on the chin rest and the head firmly forward against the band, to allow the eye to be scanned. The procedure is totally painless and takes around 10 minutes.

Side effects

No side effects have been reported.

OCT showing macular oedema in patient with intermediate uveitis.

OCT showing massive accumulation of fluid below the retina, causing multiple exudative bullous retinal detachments, in patient with Vogt Koyanagi Harada.