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UPFRONT: What We Truly See in Retina Imaging

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Luke Skywalker: Breathe. Now, reach out. What do you see?
Rey: Light. Darkness. And something else. It’s calling me.

“Star Wars: The Last Jedi”

I have been a “Star Wars” fan since my mother drove us to Philadelphia to see Episode IV just over 40 years ago. During the long drive home to New Jersey, I felt as if we were dodging all the cars around us like x-wing fighters. I have seen every movie since on opening night. Interestingly, 20th Century Fox was so unsure of the first movie, it only opened on 40 screens. This created so much demand that moviegoers would line up for hours to see the film, and forced some (like me) to drive for hours to find a theater even showing it.

In case you have not seen the latest “Star Wars” installment, I will give you a few seconds to turn the page (spoiler alert). One of the most striking scenes in Episode VIII is when Luke Skywalker fights Kylo Ren at the Battle of Crait. As Kylo slices our hero in half with his lightsaber, we find that he was actually fighting an astral projection. Ah, the old Jedi mind trick! Our mind sees things we want to see, when nothing is there. The image Luke projected to Kylo Ren was perfect to mess with his nephew’s mind; he appears much younger, he didn’t leave red footprints like everyone else, and he is using his original lightsaber that was destroyed earlier in the movie. Then, he vanishes into The Force like his mentors before him.

This idea of an apparition reminds me of looking at OCTA images. I see light and dark, obviously not in a “The Force” kind of way, but I wonder: What am I truly seing? When I look at images from my wet AMD patients, am I seeing something else? Is it a CNV, or not? Is that sea-fan-shaped object truly neovascularization, or am I imagining it? Is the absence of flow in the image truly absent flow or an artifact? Herein lies the balance of art and science in interpreting OCTA images. A good understanding of how the images are formed and what they represent helps us decide whether what we are seeing is a true representation of vessels and flow or not.

In this special issue, some of the world experts on OCT angiography give us tips and tricks we can use every day in our clinics. We learn best practices for clinic work flow and explore reimbursement issues. Finally, we look at some new software techniques such as the VISTA analysis that actually quantifies flow into a pseudocolor map. This offers us a chance to see how CNV changes with treatment and between type 1, 2, and 3 lesions. This is incredibly interesting imaging, but are we looking at the future, or is it all just a Jedi mind trick? RP