Figure 3

Composite images of the OS epithelium showing morphology and demarcation zone of corneal and limbal epithelium. The photograph of the histological cross section of the corneoscleral tissue section stained with haematoxylin and eosin highlights the corneal, limbal epithelium and the underlying stroma. The photograph was taken at 20X magnification. The corneal epithelium is 6 to 8 cell layers thick and is supported by an acellular Bowman’s membrane, which is a double layered refractile structure (marked with a black arrow) (image 3A). The termination of the Bowman’s layer also marks the termination of corneal epithelium and the beginning of limbal epithelium. Due to its distinct appearance the Bowman’s membrane is a landmark for identification of corneal epithelium from the adjacent limbal epithelium. Image (3B) demonstrates the continuation of corneal epithelium (thin arrow) into the limbal epithelium (thick arrow). The junction of these two epithelia (marked with a drop down box) is an indistinct zone the corneal end of which is demarcated with termination of the Bowman’s membrane and the limbal end of the junction is identified by the beginning of the wavy limbal basal epithelium.