Eyeworld

SUMMER 2026 | EYEWORLD | 63 C by Ellen Stodola Editorial Co-Director About the physicians Soosan Jacob, MD Director Dr. Agarwal's Refractive & Cornea Foundation Dr. Agarwal's Eye Hospital Chennai, India Aylin Kiliç, MD Medical Director and Founder Swiss Vision Group Istanbul, Turkey Jack Parker, MD, PhD Parker Cornea Vestavia Hills, Alabama Soosan Jacob, MD, first clarified the termi- nology and history of these procedures, noting that she started using CAIRS around 2015. She was doing uniform thickness CAIRS before transitioning to customized and custom-shaped CAIRS in 2017. You make mid-peripheral fem- tosecond laser channels and implant tissue seg- ments into those channels. The whole purpose is to change the shape of the cornea. She also noted the various types of CAIRS now available, including ECO-CAIRS, de- cellularized CAIRS, and CTAK. CTAK, which has become available within the U.S., started with clinical trials in 2015 as a disk that was placed within a pocket in the cornea and not as mid-peripheral segments in channels. A 2023 paper published in the Journal of Cataract & Refractive Surgery 1 described CTAK as a new procedure, however, many physicians perform- ing CAIRS label CTAK as a branded subtype of CAIRS since variations such as femtosecond cutting, customization, and decellularization were already being performed for many years with CAIRS. In addition, only conventional CAIRS currently uses custom shaping to en- hance personalization for every eye, she said. Dr. Jacob noted that she uses CAIRS frequently in her practice. Adoption is growing, Dr. Kiliç said, but is still relatively limited to specialized corneal cen- ters and early-adopter surgeons globally. Dr. Parker said he is also utilizing CAIRS frequently in his practice. It's not uncommon for him to do six or seven a week. However, he agreed that these options haven't quite hit the mainstream in the U.S. Patients with central scarring are usually not very impressed by the results with CAIRS or CTAK, he said, because even if the shape of the cornea is better, there are still reasons why they can't see through it in those with extremely advanced disease. Performing the procedure There are a couple of ways to do these pro- cedures, Dr. Parker said. The first is to do a femtosecond laser-assisted technique, which is generally straightforward, and many sur- geons are familiar with the operation. Once the C orneal tissue procedures are one of the approaches available to help treat corneal conditions, like keratoconus, and offer some patients an option other than transplantation. Several experts discussed these procedures, how they fit in with other options, and how they're being utilized today. For keratoconus, there were no good treat- ments for a long time, said Jack Parker, MD, PhD, but in the past 10 years, there have been some new developments. For a long time, the only thing we had for keratoconus patients was to offer them a full corneal transplant, and PK is not necessarily a good option for people with keratoconus because these are young people, he said, adding that it's an invasive operation with lifetime risk and obligation. There's been a longstanding desire for something better. The initial effort to fix that was DALK, but DALK is still invasive and aggressive, he said. There's also crosslinking, Dr. Parker said, which will stop the progression of disease, but it doesn't make vision better. CAIRS (corneal allogenic intrastromal ring segments) and CTAK (corneal tissue addition keratoplasty) are excit- ing because these are surgical options that can make patients' vision better, but they don't come with all the potential risks. CTAK and CAIRS represent a fundamentally different philosophy compared to traditional approaches, said Aylin Kiliç, MD. Convention- al treatments like synthetic intracorneal ring segments (e.g., Ferrara Ring [Ferrara Ophthal- mics] or Intacs [Addition Technology]), corneal crosslinking, or penetrating keratoplasty halt progression, mechanically reshape the cornea with foreign material, or replace it entirely. "CTAK and CAIRS, by contrast, use donor human stromal tissue to reinforce and reshape the cornea from within, essentially augmenting the patient's own cornea rather than replac- ing or artificially propping it," she said. "This biologic approach preserves the native tissue architecture, maintains a more natural biome- chanical profile, and avoids the immunological and mechanical complications associated with synthetic materials. They occupy a critical mid- dle ground between crosslinking and transplan- tation that was previously underserved." Expanding applications for corneal tissue procedures continued on page 64

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