This is a condition where the surface layer of cells on the cornea (the epithelium) break away periodically leading to an abrasion. Typically it occurs after a scratching injury – for example a baby scratches with a fingernail, or the eye is placed inadvertently in the path of a plant leaf or twig. There is a second group of patients who have a congenitally weak adhesion of the surface layer of cells to the underlying cornea. This group have a condition called Epithelial Basement Membrane Dystrophy (EBMD).
Recurrent erosion syndrome (RES) is more common amongst diabetics.
Symptoms
Typically these occur in the night or upon waking. The eye dries out at night and the cornea gets a little swollen. When the eye is opened, this mechanically removes a layer of cells, causing the abrasion. There is pain and watering, which may just last for a few hours (micro-erosion) or may last more than a day (macro-erosion). There may be a vicious cycle of these events occurring regularly, hence the name Recurrent Erosion Syndrome. Generally abrasions that are caused by injury get better over time; this may be over a year or so. The abrasions associated with underlying dystrophy are more difficult to cure since the new cells that grow have an abnormality, which prevents them from anchoring down.
Treatment
Simple measures, such as lubricant ointment at night, with Lacrilube or Viscotears, followed by the regular use of lubricating drops, such as Liquifilm Tears or Systane during the day can be effective. In severe cases the eye may need to be padded shut for 24 hours.
Contact lenses (soft) can be used as a bandage and are sometimes effective in breaking the cycle of recurrent erosions. They may need to be worn for several weeks at a time.
Any underlying disorder of the eyelid such as blepharitis will need to be brought under control.
Surgical treatments are directed at the underlying corneal layer and encouraging new layers of cells to anchor down.
Stromal puncture is a simple procedure where a fine needle is used to scratch the cornea, which leads to a small amount of scarring and helps the cells to stick down. This cannot be performed over the pupil area as scarring can cause some blurring of vision.
A similar approach is to shave a very superficial layer of the cornea off using an Excimer laser, followed by a bandage contact lens. One advantage of this procedure is that it can be used over the pupil area.
Complications
Rarely the cornea can become infected after an abrasion, this would require intensive treatment with antibiotics.
Various characteristic corneal surface abnormalities can be seen in these pictures.
