Basics of limbal Stem Cell Deficiency for the Postgraduates
Limbal Epithelial Stem Cells Anatomy: The healthy corneo-scleral limbus (Figure 1) is a gradual transition zone from the stratified, non- keratinised squamous epithelium of the cornea to the stratified, non- keratinised columnar epithelium with mucin-secreting goblet cells of the conjunctiva. It has 7-10 layers of cells, which have attachments similar to the corneal cells. Figure 1: Slit-lamp photograph (high magnification) of the normal limbus showing arrangement of pigmentated Palisades of Vogt in the inferior quadrant. This zone contains limbal epithelial stem cells (LSCs) that generate new epithelial cells during homeostasis and after injury or insult, to maintain corneal transparency and vision. LSCs are believed to be located within the basal layer of limbal crypts (in the palisades of Vogt) [1] and focal stromal projections (finger-like projections of stroma containing a central blood vessel, and extend upward into the corneal limbal epithelium and are surrounded by small, tight
Dr. Purvasha Narang