Eyeworld

JUNE 2022 | EYEWORLD | 83 C by Ellen Stodola Editorial Co-Director About the physicians Deborah S. Jacobs, MD Associate Professor of Ophthalmology Harvard Medical School Boston, Massachusetts Shahzad Mian, MD Professor of Ophthalmology and Visual Sciences University of Michigan Medical School Ann Arbor, Michigan S cleral lenses are an option that many physicians use to help patients suffer- ing from more severe and advanced cases of dry eye disease. Shahzad Mian, MD, and Deborah Jacobs, MD, discussed the options and how these fit into the treatment of dry eye. Any scleral lens can be a therapeutic lens, Dr. Jacobs said. There must be adequate oxygen transmission and some tear exchange. Typically, this requires a scleral lens that is more than 2 mm larger than the cornea diameter for 360 degrees, she explained. Smaller scleral lenses, sometimes called mini-scleral lenses, seal onto the ocular surface and may create a mechanical challenge to what may already be a compromised epithelial tight junction in ocular surface disease, Dr. Jacobs said. "Any commercially available scleral lens, if it is fit with appropriate attention to tear exchange and oxygen transmission, can be a therapeutic scleral lens," she said. "There are highly customized scleral lenses, such as the PROSE [prosthetic replacement of the ocular surface ecosystem, BostonSight] or EyePrintPRO [EyePrint Prosthetics], that may be necessary for eyes with unusual contours." There are many different types of scleral lenses available. The PROSE is the gold stan- dard of scleral lenses for dry eye disease, Dr. Mian said. This option was the first scleral lens approved for this indication and has been avail- able for about 2 decades. When the PROSE was first introduced, it was revolutionary in helping patients with no other options to improve vision or comfort associated with severe dry eye disease, Dr. Mian said. "We primarily used it in patients with severe diseases—Stevens-Johnson syndrome, ocular cicatricial pemphigoid—where there were no other options. Then we started seeing a lot of patients with graft-versus-host disease," he said. "Those patients are often the ones with severe disease who can't function well; our standard treatments won't work, and the PROSE is a great option." One issue initially was that the PROSE lens was only available in Boston, so patients would have to be sent there for a fitting. That limited access to only those who could go to Boston and stay there for a few days, Dr. Mian said. It wasn't practical for a lot of patients. Around 2009, the Boston group that developed the PROSE decided to expand access to certain cen- ters of excellence around the U.S., with one lo- cation being the University of Michigan, where Dr. Mian practices. "That allowed us to have a faculty member in our department trained and start doing fitting locally, and it improved access for patients around the country and revolution- ized how the clinic managed severe dry eye disease with scleral lenses," he said. Since then, Dr. Mian said a lot of other companies have come out with scleral lenses. The main difference is the PROSE is customized and has a lot of parameters that you can choose to fit patients with, so the very difficult patients still benefit from the custom PROSE devices. However, he said that other scleral lens options are good for those who don't necessarily need such a customized option. "We have trial sets, so we can try different ones, and often one is good enough for a lot of these patients." Dr. Mian added that the lenses often come at a much lower cost than a customized option. That has allowed the market to expand. The vast majority of patients can be fit into commercially available trial sets of scleral lenses. Additionally, Dr. Mian said BostonSight now makes a com- mercially available lens that is fit by trial set. Different sized lenses allow physicians to man- age other corneal conditions—like keratoconus, corneal irregularities, LSCD—in addition to dry eye disease. How they work Scleral lenses work because they vault over the cornea and you can fill them with fluid, Dr. Mian said. "When it's sitting on the surface of the eye, it's bathing the corneal surface with flu- id, so it's helping manage the dryness by always keeping a 'tear film' over the surface of the eye. Also, it's mechanically protecting the surface of the eye as a lot of issues that occur in severe dry eye patients are because of the lids constantly rubbing against the surface that's dry and caus- ing pain and discomfort," Dr. Mian said. Scleral lenses for dry eye continued on page 84

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