Corneal Dystrophies and Degenerations

Abstract

The cornea is a complex structure with complex functions aiming to protect the internal ocular tissues and transmit and refract the coming light rays. Corneal dystrophies are a group of relatively infrequent genetic corneal disorders in which an abnormal material accumulates in the cornea causing variable loss of its clarity. On the other hand, corneal degenerations are more common and usually result from physiologic changes related to aging, particular disease, or long-standing environmental insults to the cornea. Ectatic corneal disorders are usually characterized by bilateral loss of corneal biomechanical strength leading to progressive thinning and bulging of the cornea with resultant astigmatism and decreased visual acuity. In this chapter, we will describe the basic embryological, anatomical, histologic, and physiological features of the cornea. Then, we will go over the clinical, histopathologic, medical, and surgical aspects of dystrophic, degenerative, and ectatic corneal disorders.