Last reviewed 01/2018
The cornea is only 1 mm thick but is remarkably tough. It is covered by an epithelium which is continuous with the conjunctiva. Free nerve endings here account for the sensitivity of the cornea to trauma or inflammation.
The cornea is bounded anteriorly by Bowman's membrane and posteriorly by Descemet's membrane.
The innermost layer is the endothelium which acts to remove fluid from the cornea, so preventing corneal oedema; it is for this reason that the endothelium must be retained intact during eye surgery.
The cornea merges into the sclera at the limbus.
Corneal disease is classified into four categories:
- congenital and hereditary disease
- traumatic disorders
- corneal inflammation
- degenerative conditions