OCT: A Retina Odyssey
“Any sufficiently advanced technology is indistinguishable from magic.”
— Arthur C. Clarke
Peter K. Kaiser, MD
When I think of the leaps in retinal imaging technology since I started practicing, Sir Arthur Clarke's venerable laws come to mind. For example, Clarke's First Law states that when a distinguished, but elderly, scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
A very prominent retinal physician in Boston famously predicted that optical coherence tomography would never be commercially viable after being shown the technology by researchers at the Massachusetts Institute of Technology. Now, this not-so-elderly doctor uses this technology in almost every patient he sees. I still remember seeing those first OCT images in the early 1990s. It was truly remarkable to view the retina in cross-section and profess to see retinal layers in those early, noisy, false-color images on a Macintosh computer screen.
Move ahead to the present, where some have stated that the current Fourier-domain OCT devices, with their speedy detector arrays and broadband superluminescent diode light sources, are good enough for what we need to see in the posterior segment. Others note that the Ti:Al2O3 (titanium-sapphire) laser light sources, which offer 1- to 2-µm resolution, are too cost prohibitive for commercial development.
To them I quote Clarke's Second Law that the only way of discovering the limits of the possible is to venture a little way past them into the impossible.
In this issue, we will look at these “impossible” advances in imaging technology. Some will never leave the research lab, but others may change how we diagnose and treat retinal diseases in the future.
And that brings us to Clarke's Third Law, quoted above. We now routinely gaze deep inside the retina and, more recently, the choroid. We don't think twice about this amazing feat of “magic” we are performing to help our patients.
So who is Sir Arthur Clarke, and why are his rules so well known, you ask? He is best known as a science fiction writer who penned the classic novel 2001: A Space Odyssey, but his importance to you revolves around the last time you landed a plane in bad weather. When he was in the Royal Air Force, Sir Arthur worked on Ground Control Approach radar that was vital in the Berlin Airlift and is still in use in many countries to help aircraft land safely in adverse weather conditions.
Magic? Not really