There is some evidence to suggest that contact lens wear can increase the likelihood of progression of keratoconus. While the studies are not conclusive, there is significant literature that points to contact lens wear as one possible trigger for the onset of keratoconus.
It is easy to theorize how this could occur. Perhaps the contact lens is irritating the eye and increasing inflammation. Significant inflammation could then lead to a triggering event which resulted in a deterioration of the links in the collagen within the corneal stroma. Once a patient’s cornea began to deteriorate, the increased pressure on the thinning cornea would easily cause a chain reaction of events leading to keratoconus.
Many ophthalmologists or optometrists in the past have tried to keep patients in contact lenses for as long as possible, fearing the only option would be a corneal transplant. With intacs it is no longer necessary to remain in contact lenses forever and certainly a corneal transplant is not the final solution in all cases.
We would suggest that it is important to preserve the health of the cornea. In some cases this would mean that a patient with keratoconus should not be kept in contact lenses once vision began to degrade sufficiently. Instead, the keratoconus patient should be given the opportunity to have intacs placed into the cornea to strengthen the cornea against increasing elasticity of the tissue with the resultant thinning.
Intacs have been shown to be most effective when the candidates for surgery are chosen early. Late cases of keratoconus which have progressed significantly generally have poorer results after intac surgery than those which are selected for and treated earlier. While intacs can still prevent these moderate to severe keratoconus cases from requiring a corneal transplant, the vision results are not quite as promising as a person with keratoconus who is treated early.
We recommend for optometrists seeing keratoconus patients to refer early in cases that might require intac surgery. It is important not to wait until contact lenses are no longer effective. At that point the end results are less promising.