You may need investigations to help with the diagnosis or the monitoring of your condition. These will be usually be undertaken by nurses or orthoptists. For most of them, you will be seated with your chin and forehead on a rest. All of these investigations are fairly brief and non-invasive unless otherwise stated. The most common ones are as follows:
You will be asked to read letters from an eye chart, with your distance spectacles if you wear any. You will also be asked to read the chart looking through small ‘pinholes’ to help focus the image.
Intraocular pressure testing
A small device lightly contacts your eye to measure the pressure inside your eye.
OCT scan (ocular coherence tomography)
This scan captures an image of the layers of your retina and/or your optic disc at the back of your eye. It is one of the most important tests, and helps determine your diagnosis and/or clinical progress. You will be asked to stare at an image whilst a laser scans the back of your eye.
A digital photograph of the back of your eye.
This test measures the dimensions of your eye, to help determine the most suitable lens implant to use during cataract surgery.
Central Corneal Thickness
This measures the thickness of the cornea, the clear window at the front of your eye. It helps assess the health of your cornea and refine intraocular pressure measurements.
Visual Field Testing
This is a test of your peripheral vision. You sit looking into the centre of a white dome, and press a button when you see small white lights in your peripheral vision. It can take about 20-30 minutes.
Fundus Angiography (FFA or ICG)
This is used to take images of the blood vessels at the back of your eye and the blood flow through them. This is a longer investigation and further information about it can be found in the patient information leaflet.