Study of Corneal Stem Cell Transplant Shows Vision Restored After Blinding Eye Injuries

A clinical study of patients with irreversible corneal injury, published March 4 in Nature Communications, showed that transplanted epithelial stem cells from their healthy eyes restored at least partial vision in more than 90 percent of patients. 

The treatment, called cultivated autologous limbal epithelial cells, or CALEC, was developed at Mass Eye and Ear. Stem cells are removed from the patient’s healthy eye via biopsy. A two- to three-week process expands the cells into a graft, and then the graft is transplanted into the eye with a damaged cornea. 

The initial study was limited to 14 patients with unilateral limbal stem cell deficiency caused by chemical burns and other serious eye injuries. 

Researchers showed CALEC completely restored the cornea in 50 percent of participants at their three-month visit. The rate of complete success increased to 79 percent and 77 percent at their 12- and 18-month visits, respectively.

With two participants meeting the definition of partial success at 12 and 18 months, the overall success rose to 93 percent and 92 percent at 12 and 18 months.

Three participants received a second CALEC transplant, and one reached complete success by the study end visit. An additional analysis showed varying levels of improvement of visual acuity in all 14 CALEC patients.

The transplant procedure proved to be safe, with no serious systemic adverse events, particularly serious infections, despite no use of antibiotics, according to principal investigator Ula Jurkunas, MD, associate director of the Cornea Service at Mass Eye and Ear and professor of Ophthalmology at Harvard Medical School. 

“We feel this research warrants additional trials that can help lead towards FDA approval,” Jurkunas said.