On the location of the cone and the etiology of keratoconus.

I suggest that the location of the cone in keratoconus is most often located in the paracentral inferonasal quadrant of the cornea due to the presence of the most senile epithelial cells in this location. These cells may be more vulnerable than younger epithelial cells to the chronic subtle trauma of eyelid rubbing and may be more prone to release enzymes that thin the cornea.