This project aims to conduct a multicentre human clinical trial to effectively diagnose and treat limbal stem cell deficiency (LSCD) which can be caused by a number of different disease processes, all of which have a common denominator, i.e. a loss of the normal functioning epithelial stem cells of the cornea. A number of different diseases such as aniridia, steven johnson's syndrome, ocular cicatricial pemphigoid, bacterial keratitis, or chemical and thermal injuries to the cornea can lead to gradual loss of its functioning epithelial stem cells. This leads to vascularization of the cornea with surrounding conjunctival epithelium growing over it resulting in its scarring and opacification. These corneas, since vascular, no longer retain their immune privilege and prove extremely challenging to the ophthalmic surgeon. Grafting donor corneas which in normal circumstances (non vascular corneas) would give excellent results, exhibit high rates of rejection. This can be very frustrating for both the patient as well as the surgeon. Since there are a number of different contributing disease pathologies, our estimate is that there are approximately 100 patients per year in Belgium that suffer from some degree of LSCD. These patients are very often not correctly diagnosed since this is a relatively new disease first described in 1990 after the discovery of limbal epithelial stem cells in 1989. The low rates of diagnosis could potentially be increased by in vivo confocal scanning microscopy as a non invasive screening test to detect early signs of LSCD and therefore offer conservative treatment options. In the cases where total limbal stem cell deficiency has already developed, conventional corneal grafting is not suitable due to the high vascularity of the host bed. In this situation we propose transplanting standardized limbal epithelial stem cell grafts generated from the patient's own ocular stem cells (from the good eye, where available) or from HLA matched donors. Tiny 1 by 2mm superficial limbal (peripheral cornea) biopsy can be taken and the epithelial stem cells expanded in the laboratory on a biological substrate, until there is a graft measuring >8mm in diameter generated in 2 a week period. This can then be transplanted onto the diseased eye after removal of scar tissue using a novel surgical technique we have developed.