The first session on the Cornea Day program focused on surgical cornea topics, including presentations on artificial corneas, advances in endothelial disease, and avoiding or delaying transplantation.
Esen Akpek, MD, presented on artificial corneas and limitations of traditional transplants. She noted some of the key features needed for artificial corneas, which could be used in the case of donor cornea failure: flexibility, biointegration, and epithelization.
Currently, the Boston KPro is the most commonly used device globally, she said, noting that one downside is its rigid material. Because of the lack of biointegration, the device oscillates within the cornea. Inflammation is another potential downside of this device.
Can the cornea biointegrate? Dr. Akpek said the epithelium is the main structure that gives its structural stability.
She also mentioned three artificial corneal devices in various stages of development: the EndoArt (EyeYon Medical), CorNeat KPro (CorNeat Vision), and the Gore Synthetic Cornea Device (W. L. Gore & Associates).
A truly biointegrating artificial cornea is still an unmet need, Dr. Akpek said.
Anthony Aldave, MD, presented on the CorNeat KPro device. With the Boston Type I KPro, he said some of the disadvantages are the cost, the unnatural appearance, sterile donor corneal stromal necrosis, and development or progression of glaucoma.
The CorNeat is fully synthetic with a dual member optic and skirt design. It allows for biointegration. He went through the process for implantation of this device and noted results for trials so far.
The first-in-human trial had 12 devices implanted. However, nine of the 12 devices were explanted, and there was surgical difficulty in placing the corneal remnant into the posterior groove. There was also partial conjunctival retraction during the early postop period.
Because of these results, Dr. Aldave said there were modifications made to the design of the device, and there is currently an ongoing clinical trial outside the U.S.
Looking at outcomes of the modified device, 15 devices have been implanted to date, with a retention of 12 devices.
Dr. Aldave said six of the 10 patients maintained best corrected visual acuity of 20/200 or better postop, and half maintained 20/60 or better VA. Some complications did occur, including conjunctival retraction in many of the cases.
Dr. Aldave said an IDE application was submitted to the FDA in September 2020, and a clinical trial could potentially begin in the U.S. in Q2 2027.
Thomas Dohlman, MD, presented on the Boston KPro. While the Boston KPro works, Dr. Dohlman noted some of the key challenges of sterile keratolysis, extrusion, persistent epithelial defects, and retroprosthetic membrane.
He noted what’s being done in current efforts to improve biocompatibility, focusing on ocular surface optimization, reducing perioperative inflammation, and device modifications.
In terms of ocular surface optimization, Dr. Dohlman noted the importance of addressing LSCD using a medical approach and/or via ocular surface stem cell transplantation with systemic immunosuppression, using buccal mucosa overlay over Type I KPro, and minor salivary gland transplant to try to rehab the ocular surface.
Regarding inflammation, TNFα inhibition in corneal injury can help preserve the limbal niche and can also preserve optic nerve axons.
Finally, there are several device modifications to address current limitations. Dr. Dohlman mentioned the Lucia KPro, which has a modified backplate, increasing the open surface area of the KPro. He also mentioned the minimally invasive Boston KPro, which has a new design with a titanium nickel backplate that’s more flexible and has less of a footprint. This has been tested in animals and will hopefully be in human testing soon. There have also been surface modifications.
In her presentation, Maria Soledad Cortina, MD, shared when she’s using keratoprosthesis, noting that bilateral LSCD patients are the number one group that she turns to KPro for, as well as in extensively vascularized corneas. The second major reason she noted for using KPro is in prior failed keratoplasty. She has a lower threshold to switch to KPro in the elderly.
