Keratoconus is a disorder of the cornea. In keratoconus, the cornea thins and bulges outward like a cone, resulting in distorted vision. As the shape of the cornea changes, nearsightedness and astigmatism may develop. The corneal changes of keratoconus usually occur very slowly.
The cause of keratoconus is unknown. It classically develops slowly, so it is usually difficult to detect. Early symptoms include blurred vision and an increase in nearsightedness and astigmatism. As the disease progresses, irregular or oblique astigmatism may develop, causing distorted vision that is difficult to correct with glasses. Keratoconus often causes extreme sensitivity to lights and glare.
Early diagnosis of keratoconus is uncommon as the corneal changes occur slowly. However a corneal topographer can produce color maps showing the relative shape, power and elevation of the surface of the cornea. These color maps create identifiable patterns that are helpful in diagnosing the disease.
Glasses and Soft Contact Lenses may be helpful in early stages of keratconus.
Rigid Gas Permeable (RGP) Lenses may be helpful in moderate stages of keratoconus by providing a smooth surface for light refraction.
Corneal Inserts These are placed into the cornea to flatten and stabilize its shape.
Collagen Cross Linking This method works by increasing collagen cross links which are responsible for preventing the cornea from bulging out and becoming steep and irregular. An ultraviolet light is used to activate enzymes in the cornea in an effort to strengthen corneal fibers.
Lamellar keratoplasty A partial thickness graft of the cornea; only epithelium and superficial stroma is removed and replaced by donor tissue as distinct from penetrating or full-thickness grafting.
Corneal transplants work by removing the damaged cornea and transplanting a healthy cornea from a donor. During the transplant, the defective cornea is replaced by a piece of healthy corneal tissue and is held in place with sutures that are painless and nearly invisible.
Of all organ and tissue transplants, corneal transplants are the most common and the most successful. This microsurgery can restore vision to more than 90% of people suffering from corneal blindness. Procedures and techniques are constantly being improved.