Many patients have irregular corneas for the following possible reasons:
- eye diseases such as keratoconus
- scarring from corneal injury
- RK surgery
- corneal transplant
- dry eye.
Because of the irregularities on the corneal surface, these patients are unable to see 20/20 with regular eye glasses. Soft contact lenses also do not correct them to 20/20 because the soft lens follows the irregular contours of the cornea.
Most of these patients are able to obtain 20/20 vision using hard contact lenses that cover the irregular surface and create a new, smooth refracting surface. There are three types of hard lenses in use today:
- Corneal gas permeable lenses (RGP): These are small-diameter lenses that sit on the cornea. Theses are great for people with mild to moderate corneal irregularities. These are often uncomfortable at first, tend to fall out easily, move around a lot causing fluctuating vision, and traumatize the cornea because of friction.
- Hybrid lenses: These have a hard center and a soft skirt. They provide the visual benefits of RGP lenses without the discomfort and movement. However, because they sit on the cornea they cause more trauma. They also do not correct for residual astigmatism. They are good for moderate irregularities.
- Scleral lenses: These are rigid throughout. They completely vault the cornea, continuously maintaining a liquid layer on the surface of the cornea. Therefore they do not traumatize the cornea. The edges distribute the pressure on the less-sensitive white part of the eye, so they are nearly as comfortable as soft contact lenses. We can correct for any amount of residual astigmatism. They tend to be more expensive than RGP lenses, but many vision plans cover a substantial portion
Our favorite brand of the scleral contact lens is the Europa Lens from Visionary Optics. Sonoran Desert Eye Center was the first practice in the east valley to fit the scleral lens starting back in 2010. Since then, the scleral lens technology has improved dramatically. We can now create an edge design that more evenly distributes the landing throughout the entire circumference of the lens, significantly increasing comfort and decreasing redness. And the curvatures of the periphery can be designed completely independent of the optical curvatures.
Scleral contact lenses are an excellent choice for people with very severe dry eye, since they maintain a tear layer on the cornea at all times. People with dry, red, burning, light-sensitive eyes who are always squinting will be amazed at how immediately they can open their eyes entirely without discomfort.
If you want to know if scleral lenses are the best choice for you, come on in for a consult. We have fitting sets that allow us to try lenses on in the office. Call us at 480-812-2211.