It constitutes approximately 10 percent of all cases of herpes zoster.
Etiology
Varicella zoster virus. It is a DNA virus and produces acidophilic intranuclear inclusion bodies. It is neurotropic in nature.Comprehensive OPHTHALMOLOGY
Mode of infection. The infection is contracted in childhood, which manifests as chickenpox and the child develops immunity. The virus then remains dormant in the sensory ganglion of trigeminal nerve.It is thought that, usually in elderly people (can occur at any age) with depressed cellular immunity, the virus reactivates, replicates and travels down along one or more of the branches of the ophthalmic division of the fifth nerve.
Clinical features
In herpes zoster ophthalmicus, frontal nerve is more frequently affected than the lacrimal and nasociliary nerves.About 50 percent cases of herpes zoster ophthalmicus get ocular complications.
The Hutchinson's rule, which implies that ocular involvement is frequent if the side or tip of nose presents vesicles (cutaneous involvement of nasociliary nerve), is useful but not infallible.
Lesions of herpes zoster are strictly limited to one side of the midline of head.
Clinical phases of H. zoster ophthalmicus are :
1. Acute, which may totally resolve.
2. Chronic, which may persist for years.
3. Relapsing, where the acute or chronic lesions reappear sometimes years later.
