Die Limbustransplantation zur Rekonstruktion der Augenoberfläche

Abstract

Proliferation of the corneal epithelium originates in undifferentiated, long-lived stem cells that are located in the basal limbal epithelium. Stem cells are important for corneal epithelial regeneration and wound healing. Depletion of stem cells due to accidents as well as malfunctions of stem cells due to inborn or inflammatory diseases result in limbal stem cell deficiency. Limbal deficiency is characterized by conjunctivalization of the cornea with vascularization and opacification. Partial limbal deficiency can be treated by removing ingrown conjunctival epithelium thus allowing normal limbal epithelium to repopulate the cornea. Unilateral limbus-derived stem cell disease requires either limbal autograft transplantation from the healthy partner eye or kerato-limbal allograft transplantation. Several modifications of the latter technique have been performed including large kerato-limbal lamellar grafts and central penetrating kerato-limbal allografts. All homologous procedures render a very high risk of immunological reactions that require long term systemic immunosuppression. The use of amniotic membrane, better pharmacological drugs for immunosuppression and improvements in the HLA-matching of limbal allografts as well as ex vivo expansion of corneal stem cells should allow for better reconstruction of the ocular surface in limbal deficiency.

Corneal surface reconstruction using adult mesenchymal stem cells in experimental limbal stem cell deficiency in rabbits

“…With informed consent, a human placenta was donated after Caesarian section and freshly prepared under sterile conditions. As previously described, the AM was smoothly dissolved, cut in 2 cm× 2 cm pieces and fixed on pieces of cellulose with 6‐0 Prolene ® sutures (Kruse & Reinhard 2001). The samples were stored at −80°C in cell culture medium and glycerol in a 1:1 ratio (Kruse & Reinhard 2001).…”

“…The main advantage of this method is the lack of immune reactivity and therefore immunosuppression is not necessary. If the graft is too large, however, limbal stem cell deficiency can be induced in the healthy eye (Kenyon & Tseng 1989; Kruse & Reinhard 2001).…”

Bilateral sporadic aniridia: review of management

“…16 The prognosis of penetrating keratoplasty is poor because of the frequent recurrence of the same pre-graft corneal changes, followed by subsequent graft failure 17,18. This is most likely caused by the primary abnormality in the limbal stem cells of the recipient cornea.…”

Regeneración de la superficie ocular: stem cells/células madre y técnicas reconstructivas

“…La destrucción parcial o completa del epitelio limbar lleva a una cicatrización anormal del epitelio corneal, dando lugar a una serie de signos clínicos. Los principales signos son la invasión del epitelio conjuntival o conjuntivalización corneal, la vascularización y la inflamación crónica del estroma corneal 54,57 . Otros signos son un reflejo corneal irregular, una pérdida de las empalizadas de Vogt y una córnea de grosor variable 58 .…”