Kellogg Offers Multiple Options for Limbal Stem Cell Deficiency

The corneal epithelial cells that protect the surface of the eye are continuously shed throughout the day. If these cells are not replenished, the health and clarity of the cornea—and the vision—are threatened.

The only cells capable of generating replacement epithelial cells are limbal stem cells, located between the cornea and the sclera. Circumstances that can lead to the loss of limbal stem cells or limbal stem cell deficiency (LSCD) include genetic diseases such as aniridia, inflammatory conditions such as Stevens-Johnson syndrome, or trauma to the cornea from a thermal or chemical burn.

Limbal stem cell transplantation is the only intervention to counteract LSCD. “But each patient’s situation is unique, and there is more than one transplant strategy to consider,” explains Kellogg corneal transplant surgeon Shahzad Mian, M.D. “Kellogg has one of the few programs in the region able to offer multiple transplant options to “protect the long-term vision of patients with LSCD.”

When LSCD affects both eyes, the established treatment is a keratolimbal allograft, or KLAL graft —the transplantation of limbal tissue from a deceased donor into each eye. Recipients must tolerate extended systemic immunosuppression therapy following transplantation. Although KLAL has been available for decades, only high volume corneal transplant centers like Kellogg have the surgical expertise to perform it.

For patients with bilateral LSCD who are not good candidates for allograft transplantation, the best option may be keratoprosthesis, a synthetic corneal transplant. For nearly 20 years, Kellogg has been the only center in Michigan to offer this treatment option, which does not require post-transplant systemic immunosuppression.

When only one eye has LCSD, it is possible to transplant corneal limbal stem cells from the patient’s unaffected eye, a procedure called simple limbal epithelial transplantation, or SLET. “The main advantage of SLET is that it requires only a small number of the patient’s own cells,” explains Kellogg corneal transplant surgeon Nambi Nallasamy, M.D. “The impact on the unaffected eye is negligible, and systemic immunosuppression is not needed.”

While SLET is proven to be safe and effective, the procedure is not performed as often in the U.S. as it is in other countries. Outside the U.S., instances of LSCD impacting one eye tend to arise from chemical injuries or accidents, which are far less prevalent in the U.S.

Recognizing the significant potential of SLET, Drs. Mian and Nallasamy are at the forefront of “exploring next-generation applications for the procedure. In particular, they are pursuing allogeneic SLET— transplanting limbal stem cells from either deceased or living-related donors.

“We are undertaking research with our eye bank partner Eversight to determine an effective protocol to obtain limbal stem cells from deceased donors and prepare them for transplantation,” says Dr. Mian. This may decrease the immunosuppressive burden on patients treated for bilateral LSCD. The introduction of deceased and living-donor SLET will further expand the options available to treat patients with LSCD at Kellogg. Dr. Nallasamy performed the first living-related SLET surgery at Kellogg in November 2021.