Cross-sectional view of retina
Monitoring of retinal conditions / glaucoma
Optical coherence tomography has been one of the most exciting advances in diagnostic technology for the eyes. It allows us to look at the retina in cross-section and to take measurements at the back of the eye. In the last few years these machines have gone from being very rare to becoming commonplace in ophthalmic clinics and some ophthalmic optician practices. At LEDC, we offer two types of OCT scan - the Optovue RTVue and Heidelberg Spectralis. The Optovue allows us to examine the front of the eye as well, particularly for measuring the thickness of the corneas (see 'Pachymetry'). The Spectralis system combines OCT technology with autofluorescence imaging; fluorescein / ICG angiography and infra-red photography.
To take a cross-sectional image through the retina at the back of the eye or the cornea at the front. The machine achieves this by scanning the reflections from different layers in the tissue and then building them into a cross-sectional image. This will allow us to see any damage within the layers of the retina or features in the structure of the eye which are not easily visible.
The patient places their chin on a chin-rest and looks into the lens of the machine at a blue target. We may take several images depending on what information is required. In most cases, the data is compared with a database on the machine to see if it is within the expected values. Progression charts may also be produced showing changes between visits.
How Long Does This Take?
A typical set of scans may take about 5-10 minutes. This may take longer if there is a poor view of the back of the eye.