Corneal protection entails covering, or shielding, the cornea from injury or exposure. It also involves maintenance of status or integrity. When corneal protection is considered clinically, all tissues involving the orbit, eyelids, conjunctiva and nictitans, lacrimal gland tear production, and drainage system contribute to the cornea’s well-being and must be evaluated.
In purebred dogs, outer eye diseases and corneal protection issues are often associated with inherited predisposing abnormalities, such as shallow orbits, exophthalmos, lagophthalmia, entropion and ectropion, and keratoconjunctivitis sicca (KCS). In cats, inherited predisposing abnormalites are less frequent but include exophthalmos and entropion in the brachycephalic breeds. Infectious diseases in cats seem to play a more frequent role than inherited diseases in corneal protection issues.
The cornea can be conveniently examined with good magnification and illumination. Inspection of the outer eye occurs during presentation for diagnosis and also following medical and surgical therapies. The cornea is quite resilient and, despite significant challenges to its clarity and integrity, often responds successfully to treatment, thereby maintaining vision.