Brief Description, Types, Sign and Symptoms, Causes And Treatment Of Viral Keratitis

herpes simplex keratitis

Herpes keratitis is a viral inflammatory infection of the cornea (the clear, round dome covering the dark colored part of the eye) which is caused by the herpes simplex virus (HSV) and it is commonly called herpes simplex keratitis.

Herpes simplex virus is of two major types: HSV type I typically causes infection above the waist and is the most common and primarily cause of face infection (eg cold sore or fever blister). It is acquired by kissing or by coming in close contact with a patient suffering from herpes labialis. HSV type II causes infection below the waist and is sexually transmitted. It is transmitted to the eyes of neonates through infected genitalia of the mother.

Although herpes Simplex keratitis usually heals without damaging the eye, but in more severe cases it can lead to scarring of the cornea or blindness.

herpes zoster ophthalmicus

Another rare type of herpes infection affecting the eye is herpes zoster ophthalmicus which caused by Varicella-zoster virus. The infection is contracted in childhood, which manifests as chickenpox and the child develops immunity. The virus then remains dormant in nerve cells of the skin and eye (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 nerves that supplies the skin of the forehead and scalp, the lacrimal gland (tears gland) etc. Lesions of herpes zoster are strictly limited to one side of the midline of head and about 50 percent of cases get ocular complications.

The presence of herpes simplex virus in the eye typically infects the eyelids, conjunctiva (the thin, filmy, mucous membrane that covers the inside of the eyelids and the white part of the eye) and cornea (the clear, front window of the eye). It may also infect the deeper layers of the eye which leads to scarring of the cornea, loss of vision and sometimes even blindness. But if the infection is superficial, involving only the conjunctiva and cornea’s outer layer (called the epithelium); it will usually heal without scarring. If herpes keratitis is left untreated, it can severely damage the eye.

Signs and Symptoms

Patients with herpes simplex keratitis may complain of the following:

• Blurred vision
• Eye redness
• Eye pain
• Blurred vision
• Sensitivity to light
• Watery discharge

The development of small, raised, clear vesicles has been marked as the earliest sign of active viral replication in the corneal epithelium. However, the most common presentation of herpes simplex keratitis is dendritic ulcer (or amoeboid ulcer). The prominent features of dendritic ulcers include a linear branching pattern with terminal bulbs, swollen epithelial borders, and central ulceration through the basement membrane.

 Treatment

Actually there is no complete cure for herpes because once the virus is in the body, you cannot get rid of it but if you develop herpes keratitis, you can do the following to prevent recurring outbreak: 

• Avoid touching your eyes If you have an active cold sore or blisters. 
• Never use steroid eye drops because they encourages virus multiplication. 
• If you are a contact lens wearer, it is very vital to safely handle, clean and store your contact lenses to reduce your risk of developing keratitis. 
• Visit an eye doctor as soon as possible if symptoms of ocular herpes return.

It is very necessary and important to consult your eye doctor before indulging in any form of treatment this is because some medications or eye drops may actually make the infection worse.

The main treatment of HSV keratitis usually involves the use of antiviral medications in form of eye drops or oral tablets. However, surgical intervention (although rarely necessary) may be considered if there is scarring on the eye and vision loss.