Contact lenses for keratoconus
Keratoconus is a bilateral corneal ectasia that causes progressive non-inflammatory corneal thinning. The beginning is usually in adolescence and can progress to adulthood.
At first, with glasses you can get a good vision, but as you move on, contact lenses have to be adjusted.
In mild cases, with soft contact lenses, but, thicker, it can be achieved a successful adaptation.
Most normal, however, is to adapt gas permeable rigid contact lenses. The main reason is that the cornea is pumped, it loses symmetry and the result is a distorted vision, usually with high myopia and astigmatism. Rigid contact lenses restore symmetry because between back surface of the lens and the cornea it is filled with tears.
Until recently, they were very small lenses because of the lower pumping, they were quite difficult to adapt. Today, large-diameter semi-scleral and scleral contact lenses can be adapted. The main advantage is superior comfort
In keratoconus, normally the lower cornea is a pumped
The contact lens again creates a regular surface, providing a good image quality