To review the effects of long-term contact lens wear on the cells of the cornea.
Published investigations into the effects of long-term contact lens wear on the corneal epithelium, keratocytes, and endothelium were reviewed.
Results from multiple studies indicate that long-term daily wear of contact lenses causes endothelial polymegethism but has no effect on corneal epithelium (thickness, surface cell size); keratocytes (density, stromal reflectivity); or endothelial cell density, permeability, or pump rate. Extended wear also causes no endothelial changes other than polymegethism, but it affects the epithelium (decreased thickness, increased surface cell size) and keratocytes (possible decreased density).
Investigators have not found detrimental effects on the cells of the cornea from the long-term use of daily wear contact lenses. Although contact lenses cause endothelial polymegethism, no functional deficits ensue. Extended wear lenses may cause changes in all three cell types, but it is not known if these effects are detrimental nor if they occur with newer lenses of higher oxygen transmissibility. Patients can be reassured that modern contact lenses can be worn for many years in daily wear fashion (and possibly in extended wear with lenses of very high oxygen transmissibility) without damaging the cells of the cornea.