What injuries, and irregularities affect the cornea?
Some trauma, including projectile foreign bodies, lacerations and blunt trauma can cause scarring that clouds the cornea. Hereditary conditions including degenerations and dystrophies may also cloud the cornea. The most common hereditary condition seen in young people is keratoconus, a condition in which the cornea assumes a cone shape. This is common in children with Down’s syndrome and in people with allergic conjunctivitis. These patients may be able to use contact lenses or glasses for a period of time, but may eventually develop scarring and high astigmatism that cannot be corrected without corneal transplantation. Occasionally, it may become necessary to perform a corneal transplant following cataract surgery, if bullous keratopathy occurs. Bullous keratopathy is a condition where the endothelial cells on the back of the cornea decrease in number after cataract surgery. However, this is less common today because of new techniques and improved lens design.