Implantation of intrastromal corneal ring segments may be considered medically necessary for the treatment of keratoconus in patients 21 years of age or older who meet the following criteria:
The patient has experienced a progressive deterioration in vision, such that he or she can no longer achieve adequate functional vision with contact lenses or spectacles; AND
Corneal transplantation is the only alternative to improve their functional vision; AND
The patient has a clear central cornea with a corneal thickness of 450 microns or greater at the proposed incision site.
Implantation of intrastromal corneal ring segments is considered not medically necessary as a treatment of myopia.
Implantation of intrastromal corneal ring segments is considered investigational for all other conditions.