Custom Corneal Gas Permeable (GP) Lenses:
Corneal GP lenses are the classic choice to mask corneal surface irregularities and to improve visual acuity. These lenses are also referred to a hard lenses, rigid lenses and RGP (rigid gas permeable) lenses. Using corneal GP lenses on a cornea that has very minor irregularity is similar to fitting them for refractive correction on a normal cornea. However, fitting corneal GPs becomes increasingly difficult as the corneal surface becomes more irregular. Success of these lenses depend greatly on the severity and location of the corneal irregularity. Many patient whom have had difficulty with GP lenses in the past generally have irregularity that is too severe to be successful with this type of lens. These lenses are lathe-cut and can be produced in an extensive range of base curve radii, diameters, materials, and nearly endless refractive powers. When fitting a corneal GP lens, precision of fit is of the utmost importance to maintain the corneal integrity and lens comfort. Additionally GP lenses have proven useful in deciding if surgical intervention may be beneficial.
