Hi Chow
Corneal abrasions, or scratches to the corneal surface, cause what we call an 'epithelial defect'-a raw area not covered by the epithelial layer of cells of the eye.
This layer grows back and covers the 'epithelial defect' very quickly, usually within a couple of days for small to moderate abrasions.
Sometimes, the layer grows back and sticks back to the eye normally, and the patient has no further problems at all. Othertimes, as may have happened in your case, the epithelium grows back to cover the raw surface but does not stick back to the underlying layer properly-ie it remains 'loose'. As a result, the patient may develop recurrent eye pain-especially in the morning on waking. This is because the eyes dry out while sleeping, and upon waking, the upper eyelid may be slightly stuck to the corneal epithelium. If the epithelium is loose, the eyelid opening may loosen it further or even tear open the epithelium again. This is called recurrent corneal erosion syndrome and is usually treated with Duratears or similar eye ointment at night.
If you have recurrent erosion syndrome, you should not have conventional LASIK with a flap. The condition will remain a problem and may even worsen.
Recurrent corneal erosion syndrome is usually treated with night time ointment, but if this does not work, 'laser phototherapeutic keratectomy (PTK)' surface ablation is a very effective option. PTK is like epiLASIK or PRK, except that very little cornea is ablated since usually there is no intention to treat any spectacle power.
By the same token however, doing 'epiLASIK'/PRK will cure the recurrent corneal erosion syndrome while at the same time correcting the spectacle power-ie killing 2 birds with one stone. epiLASIK/PRK is basically PTK but done with a slightly different pattern and going deeper into the cornea.
Bear in mind that you still need the usual checks for suitability if you are thinking of correcting the myopia, since you need to ensure sufficient corneal thickness etc. Doing it for high myopia does carry a somewhat higher risk of haze/scarring, but this risk can be minimised by using a medicine called mitomycin C for a sufficient length of time.
