The cornea is the clear front "window" of the eye over the coloured part. The very front part of the cornea is called the epithelium.
A corneal erosion is a breakdown in the epithelium caused by a weakness in the adhesion of the epithelium to the rest of the cornea. This typically causes pain, redness and watering on waking up because opening the eyelids tears a few cells from the corneal surface.
- Inherent weakness in the cornea - sometimes this weakness is inherited, and sometimes it follows other corneal disease.
- Result of poor healing following a simple injury.
The most common treatment is to generously lubricate the eye (especially before sleeping) to decrease the friction between the upper eyelid and the cornea and allowing the damaged epithelium to heal.
Corneal erosions that are recurrent often ,require the prolonged use of ointments at bedtime (sometimes for six months or more). Sometimes a contact lens is used to facilitate healing. Other treatments may require the gentle removal of the abnormal epithelium. If the problem is recurrent and very troubling, the doctor may consider minor surgery to try to heal the eye - micropuncture of the surface, or excimer laser treatment.
If bacteria get into the tissues under the protective corneal epithelium, infection or corneal ulcer can occur. These can be very serious and may cause permanently decreased vision in the eye.