ARVO 2024: Reliability of contact specular microscopy in the corneal endothelium

At this year's ARVO meeting, the Eye Care Network spoke with Elias Kahan, MD, a clinical research fellow in the Department of Ophthalmology at the New York University Grossman School of Medicine. He spoke about his poster on contact specular microscopy and its implications for future corneal endothelial research.

Editor's note: The below transcript has been lightly edited for clarity.

Elias Kahan, MD: Hi, my name is Elias Kahan. I'm a clinical research fellow and incoming PGY1 resident at NYU. I'm here to talk about my poster, "Contact specular microscopy reliably images the same location of the corneal epithelium." In my poster, we discuss the use of a wide-field contact slit scanning specular microscope recently developed by Konan Medical. And what makes this device unique is that it allows us to image the far periphery of the endothelium. So, conventional, noncontact devices image the central and paracentral, so a few millimeters from the central, of the endothelium. This device allows the imaging all the way to the limbus in all directions.

In the course of imaging a number of individuals, we found that applanating the cornea, applying pressure, creates physical distortions in the endothelium. You can think of them as wrinkles, or, as we call them, undulations. Over the course of imaging, we found that, as we moved the lens across the endothelium, these, these distortions, these anatomic landmarks, were static, and they didn't change. So we wanted to understand whether we could use them to map the endothelium and return to the same location over time. So we created a pilot study where we imaged 20 eyes, and we had them come back a week or 2 later, and we tried to identify the same location that we found in the first visit. So out of the hundreds of thousands of cells in the endothelium, we were able to pinpoint individual, unique cells weeks apart using these physical distortions, or as we call them, anatomic landmarks, as a map. So we imaged about twenty individuals. In fifteen of them, we were able to find the same exact cell. We analyzed the morphologic metrics of the endothelium and found very high intraclass correlation coefficients, which made us feel confident that this was repeatable.

Looking long-term, we believe that we could use this to better track the progression and the impact of medical or surgical interventions in patients with corneal disease. So in patients with Fuchs, for example, we can't really study the far periphery using conventional microscopes. So using this device, we can image the far periphery and understand behavior of cells near the limbus. And, using this methodology, we could identify individual cells and then track their progression over time. So, if a patient were to receive a ROCK [Rho Kinase] inhibitor or Descemet stripping only, we would [be] able to use, theoretically, use this methodology to see how those cells behave. As of now, we've only imaged in healthy individuals, but the next step of this project is to increase our sample size in healthy individuals and image patients with corneal disease to validate it and hopefully integrate it moving forward.