CORNEA EWAP JUNE 2023 35 whether DMEK will outperform DSAEK in complex eyes. “Important outcomes of this trial will be endothelial cell loss and graft survival at 6 months and 2 years,” he said. “An intriguing arm of the trial will include supplementing a randomized cohort of the patients with postoperative topical ripasudil, a rho-kinase (ROCK) inhibitor, which may promote faster corneal clearing or even longer graft survival by reducing endothelial cell stress.” If this trial shows that DMEK outperforms DSAEK in even complex eyes, Dr. Chamberlain said we’ll see an even broader adoption of DMEK. While DMEK is on the rise and surgeons are becoming adept at it, like the full thickness transplants and other lamellar keratoplasty techniques that came before it, someday DMEK might even become antiquated. “Endothelial cell cultures are being developed by several entities (Aurion Biotech and Emmecell) and are now in clinical trials and may supplant some of these surgeries, if results look promising,” Dr. Chamberlain said. “Additionally, rho-kinase inhibitors and recombinant bioengineered fibroblast growth factor may be pharmaceutical agents that promote endothelial cell migration and proliferation that could be exploited to clear corneas with Fuchs dystrophy without transplanting allogeneic cells at all. These agents are in various stages of clinical trials.” “If our technologies with endothelial cells start to gain traction, we may someday see the disappearance of all endothelial keratoplasty,” Dr. Venkateswaran said. “Many surgeons taught themselves DSAEK because the technique didn’t exist during their training; they then taught themselves DMEK. Our therapeutics are constantly advancing. Young ophthalmologists are fortunate because they currently learn DSAEK and DMEK in training. … However, what we are being trained in may grow extinct in the future.” EWAP References 1. Matsou A, et al. Microthin Descemet stripping automated endothelial keratoplasty versus Descemet membrane endothelial keratoplasty: a randomized clinical trial. Cornea. 2021;40:1117–1125. 2. Rose-Nussbaumer J, et al. Descemet endothelial thickness comparison trial: two-year results from a randomized trial comparing ultrathin Descemet stripping automated endothelial keratoplasty with Descemet membrane endothelial keratoplasty. Ophthalmology. 2021;128:1238–1240. Editors’ note: Dr. Chamberlain is Professor of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon. He has interests with ASLAN Pharmaceuticals, Cambium, Kowa Pharmaceuticals, LEO Pharma, Noveome Biotherapeutics, Oyster Point Pharma, Regeneron, and Trefoil Therapeutics. Dr. Chan is Associate Professor of Ophthalmology, University of Toronto, Toronto, Canada. She has interests with Aurion Biotech. Dr. Venkateswaran is in practice with the Cornea and Refractive Surgery Service at Massachusetts Eye and Ear, Waltham, Massachusetts. She has interest with CorneaGen. breakup measurement with the Oculus Keratograph and an anterior segment OCT device to image the epithelium, Dr. Schallhorn said. “This can help determine the source of the irregularities seen on Placido disc imaging or exam,” she explained. Dr. Schallhorn said maintaining a stable tear film is key to achieving the best possible image quality. “For the vast majority of patients, this is the major modifiable factor in image quality. Paying attention to tear film stability and managing lid health is of utmost importance. Many patients can have an unstable tear film but not report dry eye symptoms, so paying attention to the exam findings is the only way to detect this.” Dr. Waring said he considers all of these technologies that have enabled and improved assessment of image quality important to the staged approach of assessing current image quality and image quality potential from the front to back of the eye. “What may have been thought of as nice to have 10 years ago can be a need to have 10 years later,” he said. “It depends on the practice pattern of the surgeon and the goals of the surgeon and the patient.” Dr. Schallhorn said her most vital measurements for cataract surgery are a thorough exam and Placido disc topography. “This will tell you most of what you need to know,” she said. The other important contributor to image quality is the retina. Routine preoperative macular OCT should be performed in any patient considering an advanced-technology IOL, as even subtle findings can affect the outcome of surgery. In patients with abnormal topography, combined ray tracing/Placido disc imaging is nice to have to sort out the relative contribution of the cornea and lens to image quality, Dr. Schallhorn said, noting that this technology is essential for the 45- to 60-year-old age group deciding between lens vs. corneal surgery. For patients with irregular topography and early cataracts, knowing the relative contribution of each to the image quality can be helpful in preoperative patient counseling and setting expectations. “As the diagnostic capabilities of our imaging devices continue to advance, we can start to move the conversation and the goal of surgery beyond a acuity number and into an era of optimizing image quality,” she said. EWAP Reference 1. Gouvea L, et al. Objective assessment of optical quality in dry eye disease using a double-pass imaging system. Clin Ophthalmol. 2019;13:1991–1996. Editors’ note: Dr. Schallhorn is Rose B. Williams Endowed Chair in Corneal Research, University of California, San Francisco, San Francisco, California. She has interests with Carl Zeiss Meditec and Novus Vision. Dr. Waring practices at Waring Vision Institute Mt. Pleasant, South Carolina. He has interests with Johnson & Johnson Vision, Oculus, Tracey Technologies, and Visiometrics. Preoperative ‘IQ’ - from page 29
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