People who have undergone LASIK surgery or Radial Keratotomy (R-K) surgery can sometimes be left with some refractive error in the form of nearsightedness, farsightedness, or astigmatism. This astigmatism that can happen after refractive surgery is called irregular astigmatism. Irregular astigmatism is astigmatism where the difference in the powers of the cornea are not 90 degrees apart. It is associated with blurred, distorted vision loss which is not correctable with glasses. It is one of the most serious and frequent complications of corneal refractive surgery.
For people who have irregular astigmatism as a complication of their refractive surgery, glasses are not an adequate solution to correct that irregular astigmatism. A rigid contact lens is the only solution to correct for irregular astigmatism. The usual type of rigid contact lens is a corneal contact lens, sometimes called a rigid gas permeable (RGP) lens. The problem with this type of lens is that it is small and sits on the cornea of the eye. This type of corneal rigid lens in not an option for people who have undergone corneal refractive surgery as their corneas are not as strong and stable after their refractive surgery.
An excellent option to correct for irregular astigmatism and any resultant refractive error from refractive surgery is a scleral contact lens. It gives the clear, sharp vision benefits of a rigid contact lens with the comfort of a soft contact lens.
Scleral contact lenses are fit to vault over the cornea which had the corneal refractive surgery so they are healthy for the eye. They do not rest on the cornea thereby providing the safest contact lens option for people who have undergone corneal refractive surgery.
Scleral contact lenses provide excellent comfort to people by landing on the sclera of the eye which is less sensitive so they provide excellent comfort.
Scleral contact lenses can be fit by first doing a topography reading and designing the lens based on all 11,000 points from this topography reading. This custom design process produces a precise individual lens for every patient. This allows a precise design for every possible type of cornea that has undergone corneal refractive surgery. This system prevents any trauma to a cornea that has undergone corneal surgery by ensuring an exact alignment and fit.
The fit of a scleral contact lens can be evaluated by on O.C.T mapping. This mapping ensures an exact fit to ensure the cornea is properly and safely vaulted and the scleral contact lens lands safely on the sclera of the eye.