The past, present and future of OCT imaging

Optical coherence tomography (OCT) was first introduced commercially in 1996, measuring reflected light to produce detailed cross-sectional and 3D images of the retina. However, it was not until 2002 that the technology was widely accepted in clinical ophthalmology and optometry and began helping eye care professionals visualise retinal changes in a way they had never seen before.

The first OCT technology widely accepted in clinical practice was time-domain OCT (TD-OCT), and it transformed the practice of medical and surgical retina. However, TD-OCT used a moving reference mirror for measuring the time it takes for light to be reflected and this relatively slow, mechanical process limited both the amount of data that could be captured as well as image quality. TD-OCT data was acquired at approximately 400 A-scans per second with an axial resolution of 8-10µm in tissue. This meant that image acquisition times were slow, and no eye tracking facility was offered, so images were greatly impacted by motion artefacts. Additionally, image resolution and the density of volume scans were low, limiting the practicality of using TD-OCT for the diagnosis and management of patients.