Macula
Fluid, swelling, membranes, macular holes and AMD changes can be assessed within individual layers.
Detailed cross-sectional images, without touching the eye
Optical coherence tomography (OCT)
OCT uses light to create detailed cross-sectional images of the retina and optic nerve. It reveals fluid, changes in layers and nerve fibre loss that may not be visible in a standard examination.
Understanding the procedure
An optical cross-section of the retina.
The device sends faint, invisible light into the eye and analyses its reflection. This produces cross-sectional images and thickness maps without X-rays or contact with the eye.
We assess raw images, automatic segmentation, signal quality and previous scans. A coloured device alert alone is not a diagnosis.
- Technology
- Imaging with light
- Contact
- Non-contact
- Duration
- usually a few minutes
- When it is used
- Macula, optic nerve and the front of the eye
Used where needed
What can an OCT scan show?
The scan protocol is chosen for the clinical question.
Glaucoma
We measure the nerve fibre layer and optic nerve structures and monitor changes over time.
Diabetes and vascular occlusions
Macular swelling can be measured, allowing us to document changes and the response to treatment.
Cornea and the front of the eye
Suitable systems can show cross-sections of the cornea, anterior chamber and drainage angle.
Step by step
This is how an OCT measurement takes place.
Imaging is painless; you mainly need to keep your gaze steady.
Position
You rest your chin and forehead on the device. Glasses or contact lenses are removed where the measurement requires it.
Keeping your gaze steady
Look at the target light while the device performs one or more scans.
Checking quality
We check alignment, signal strength, movement and automatic detection of tissue layers.
Comparing changes over time
We compare current and previous images alongside visual acuity and clinical examination findings.
Understanding the results
Good images need careful capture and interpretation.
Thickness measurements are compared with a reference database. Anatomical variations, high myopia, clouding or incorrectly detected layer boundaries can produce apparently abnormal readings.
Follow-up comparisons need consistent scan positions, good image quality and comparable device protocols. Small differences do not necessarily mean real deterioration.
Well prepared
How to prepare for your visit
- usually no special preparation
- Briefly remove contact lenses if necessary
- Bring previous OCT printouts or digital records
- do not drive yourself home if your pupils will be dilated
Frequently asked questions
Clear, concise answers.
Is OCT harmful?
OCT uses light, without ionising radiation or contact with the eye. It can be repeated when needed.
Why does health insurance not cover every OCT scan?
Reimbursement depends on the diagnosis, reason for testing and insurance policy. We tell you beforehand if the examination is offered as a self-funded service.
Can the OCT safely exclude glaucoma?
No. It is one important part of the assessment, alongside the optic nerve, pressure, visual field and risk factors.
Medical note
This page cannot replace an eye examination. Your symptoms, history and findings determine which tests are useful and how their results should be interpreted.
Medical basics
Sources and further information.
Related topics
All non-surgical eye care services