Recurrent Corneal Erosion
The cornea is the clear dome in the front of the eye. It covers the iris (the colored portion of the eye) and the round pupil. The cornea is composed of five layers. The outermost layer is the epithelium.
When the epithelium does not adhere correctly to the rest of the corneal tissue, this can cause a condition called recurrent corneal erosion.
Typically, the sufferer wakes up in the morning with a foreign body sensation. Here is the mechanism:
Water leaves the cornea both by evaporation and through the action of pump cells on the back of the cornea. At night there is no evaporation through the closed eyelids. Water is able to loosen a patch of epithelial cells, which then stick to the back of the eyelid rather than the cornea when the patient first opens the eyes in the morning. This leaves a bare patch on the surface of the cornea. Raw nerve endings poke up through the exposed area. This can be extremely painful.
There are many possible causes of recurrent corneal erosion, including a history of corneal injury, such as corneal abrasion, and various corneal diseases.
To detect and evaluate corneal erosion, your ophthalmologist (Eye M.D.) or optometrist may instill eye drops with yellow dye in your eye and examine your eyes using a slit-lamp microscope. In the short-term, the eye doctor will probably remove the loose epithelium after numbing the cornea with drops. Pain relief is often an issue, and may be dealt with through patching, pain pills, or other measures.
After the episode is resolved, we try to prevent a recurrence. A prescription of concentrated saline solution drops and ointment to help your epithelium adhere to the underlying tissue may be given. Should you continue to experience recurrent corneal erosions despite this, your doctor might suggest an additional procedure to make the loose patch of cells adhere to the rest of the cornea. These treatments may include procedures to remove the damaged epithelium, removal of corneal cells using a laser, or performing an anterior stromal puncture, which involves making tiny holes on the surface of the cornea to promote stronger attachments between the top layer of corneal cells and the layer of the cornea underneath.