OCT (Eye Scan)

An OCT scan, short for optical coherence tomography, is a non-invasive imaging test that uses light waves to capture highly detailed cross-section images of the back of the eye. It shows the separate layers of the retina and the optic nerve in fine detail. The scan does not use radiation and does not make contact with the eye.

An OCT scan helps eye specialists detect, diagnose, and monitor a range of eye conditions, including age-related macular degeneration, diabetic eye disease, and glaucoma. By revealing very early changes in the retina, it allows problems to be picked up before they affect vision noticeably. Repeat scans also help track whether a condition is stable or changing.

Usually no special preparation is needed. Sometimes drops are used to widen your pupils so the back of the eye can be seen more clearly; these can blur your vision and make your eyes sensitive to light for a few hours, so it is sensible to arrange a lift home. Bring sunglasses and let the team know if you wear contact lenses.

You sit at the scanning machine and rest your chin and forehead on supports to keep your head steady. You look at a target light while the scanner passes a beam of light across your eye to capture the images. Nothing touches your eye and the scan is painless, taking only a few minutes for both eyes.

The detailed images are reviewed by your eye specialist, often during the same visit. They show the thickness and condition of the retinal layers and can reveal swelling, fluid, thinning, or other changes linked to eye disease. Your specialist will explain the findings and may recommend treatment, monitoring, or a follow-up scan to track any changes over time.