The herpes simplex Type I virus will lie dormant in the nerve root of the trigeminal nerve at the base of the brain , being held in check by the body's immune defenses . When the body's immune system becomes weakened , for whatever reason , the virus can travel down the length of the trigeminal nerve to the nerve endings in the cornea , releasing infectious virus particles. An immunologic alarm is then triggered leading to inflammation of the cornea. In some cases of herpetic keratitis , an active viral infectious process occurs leading to epithelial herpetic disease with ' herpetic dendrites '. Herpetic dendrites have a classic zigzag appearance , reflecting the branching pattern of the corneal nerve endings.
Epithelial disease is treated with anti-viral medications.
In general , steroid medications are contraindicated for infectious epithelial herpetic disease. Steroid medications do have a role to play in the treatment of herpetic stromal disease. Anti-viral medications are often used in conjunction with steroids to treat stromal disease .