Eight corneal clinical challenges for primary care optometrists.

Since the cornea is an avascular tissue and does not possess its own elaborate system of defenses, its response to insulting agents is multifactorial and varies according to the immune response of the host, the virulence of the infecting organism, and the site of infection. An overview of clinical conditions with different etiologies is presented here, with a discussion of the various responses of the corneal tissue to a variety of ocular pathogens.