Abstract
Purpose: :
The catastrophe of toxic, mechanical or thermal damage of the ocular surface results in conjunctivalization, chronic inflammation and vascularization and this is inconsistent with a good function of the affected eye. A deficiency of limbal stem cells (LSCD) is crucial for these severe complications. A three-step surgical procedure was established: first allay of inflammation, than transplantation of ex-vivo cultivated limbal epithelium (TCLE) followed by perforating keratoplasty which led to a permanently clear, non-inflamed corneal surface.
Methods: :
Ten patients, with a follow up over 50 month after TCLE were examined to measure the long-term efficiency. Retrospectively the post operative course and management as well as the visual improvement were analyzed. Furthermore we performed real time PCR, western-blotting and immunofluorescence in order to proof the existence of lineage markers of corneal epithelium (K3/ K12), conjunctiva (K19, MUC5AC) as well as markers of inflammation (Il-1alpha and beta, ICAM-1, VCAM-1) and vascularization (VEGF) in a central corneal button eight years after TCLE.
Results: :
No patient has had a decrease of vision, some of them needed subconjunctival Avastin injection because of cornea vascularization. The patient’s corneal epithelium showed similar K3/K12 expression and immunofluorescence staining compared to healthy cornea at a significant higher level than in the conjunctiva. Accordingly, the expression and immunreactivity for K19 was on a negligible amount and the goblet cell marker MUC5AC was not detectable. Inflammatory markers IL-1alpha and IL-1beta showed an even lower expression level than in normal cornea and conjunctiva. Expression of VCAM was slightly elevated in comparison to control cornea, but still significantly lower than in conjunctiva. Furthermore, expression levels of VEGF and ICAM were comparable to cornea and lower than in conjunctiva.
Conclusions: :
Visual acuity increase and corneal epithelial characteristics sustain stable over long time after TCLE and emphasize the effectiveness of the described surgical approach for ocular surface reconstruction in LSCD.
Keywords: cornea: epithelium • transplantation • visual acuity