Autologous fibrin-cultured limbal stem cells permanently restore the corneal surface of patients with total limbal stem cell deficiency

Background. Ocular burns cause depletion of limbal stem cells, which leads to corneal opacification and visual loss. Autologous cultured epithelial ce lls can restore damaged corneas, but this technology is still developing. W e sought to establish a culture system that allows preservation of limbal s tem cells and preparation of manageable epithelial sheets and to investigat e whether such cultures can permanently restore total limbal stem cell defi ciency. Methods. We selected a homogeneous group of patients whose limbal cell defi ciency was evaluated by scoring the gravity of the clinical picture and the keratin expression pattern. Stem cells, obtained from the limbus of the co ntralateral eye, were cultivated onto a fibrin substrate and their preserva tion was evaluated by clonal analysis. Fibrin cultures were grafted onto da maged corneas. Results. Fibrin-cultured limbal stem cells were successful in 14 of 18 pati ents. Re-epithelialization occurred within the first week. Inflammation and vascularization regressed within the first 3-4 weeks. By the first month, the corneal surface was covered by a transparent, normal-looking epithelium . At 12-27 months follow-up, corneal surfaces were clinically and cytologic ally stable. Three patients had a penetrating keratoplasty approximately 1 year after restoration of their corneal surface. Their visual acuity improv ed from light perception or counting fingers to 0.8-1.0. Conclusions. Preservation of limbal stem cells in culture gives new perspec tives on the treatment of ocular disorders characterized by complete limbal stem cell deficiency. The multicenter nature of this study and the handine ss and ease of long-distance transportation of the fibrin-cultured epitheli al sheets suggest that this technology can now be widely applied.