Corneal epithelial stem cell deficiency : in vivo and in vitro analysis of diagnostic features and treatment outcomes

Several clinical and laboratory studies suggest that the niche for corneal epithelial stem cells is located in the corneoscleral limbus. Of particular interest are the palisades of Vogt (POV), which are a series of fibrovascular palisade like structures found predominantly along the superior and inferior limbus. The study was designed to use a relatively new and powerful tool, the laser in vivo confocal microscopy (Rostock corneal module confocal microscope) of scanning laser ophthalmoscope, ) HRTII; to evaluate in details normal anatomical features of the limbus and establish diagnostic features of the defective limbus in patients manifesting clinically with limbal stem cell deficiency (chapter two, three and four). The objective was to be able to diagnose early and late cases of limbal stem cell deficiency without the need fgr invasive methods such ., impression cytology or ocular surface biopsy. Th~ features determined IVCM were validated and correlated with features observed in vitro by histological examination of biopsy specimen. {., Over the last 10 years approximately 25 to 30 patients have undergone limbal stem cell transplantation in the department with at least a one year follow up. The other aim of this study was to evaluate retrospectively and prospectively the outcomes of these procedures (chapter five), to assess the quality of life benefit of the procedures on the patients using a modified National Eye Institute Visual Functioning Questionnaire 25 (NEI II I I I 1 VFQ-25) (chapter six) and to examine the donor eyes and donor sites used for harvesting tissue for limbal transplants both clinically and by confocal microscope (chapter seven). Finally, we hypothesized that gravity may influence the differential migration of cells from the superior and inferior limbic regions, and carried out a simple experiment in vitro which supported this hypothesis (chapter eight). IIIEThOS - Electronic Theses Online ServiceGBUnited Kingdo