Cell sloughing with proparacaine

The corneal epithelium sloughs cells directly into the pre-corneal tears. By irrigating tears from the surface of the cornea under different circumstances it is possible to compare the rates at which cells are sloughed. In this experiment the rate of appearance of cells following one drop of topical anesthetic was compared with the same eye without the drop. Initially the anesthetized cornea sloughed less, but later more cells were sloughed. This effect lasted for at least 6 hours, and showed that the return of normal sensation is only the initial part of a recovery process which takes much longer.