Keratitis – Causes, Symptoms and Treatment

A term used to define a wide variety of corneal infections, irritations, and inflammations; since each type of condition is unique, medical diagnosis and treatment is essential. Corneal ulcers are commonly caused by bacterial or fungal invasions following superficial corneal abrasions; among the common infectious agents are: staphyloccus, streptococcus, herpes (both simplex and zoster), adenovirus, rubeola, rubella, mumps, trachoma, infectious mononucleosis, and pneumococcus; also at fault may be Vitamin A deficiency or broad spectrum antibiotic drug reactions.

Corneal ulcers may also follow trauma, may be associated with other eye infections (e.g., conjunctivitis), may be related to other corneal disorders.

Keratitis is a medical condition of the eye in which the cornea is inflamed. Bacterial infection of the cornea can follow from an injury or from contact lens wearing. Viral infection of the cornea is usually caused by herpes simplex virus and called a 'dendritic ulcer' due to its shape when looked at with a slit lamp. Amoebic infection of the cornea is the most serious corneal infection, usually only affecting soft contact-lens wearers.

Causes
A wide variety of conditions can lead to inflammation of the cornea. Among them are viral, bacterial, or fungal infections; exposure to ultraviolet light such as sunlight or sunlamps; exposure to other intense light sources such as welding arcs or snow or water reflections; irritation from excessive use of contact lenses; dry eyes caused by an eyelid disorder or insufficient tear formation; a foreign object in the eye; a vitamin A deficiency; or a reaction to eyedrops, eye cosmetics, pollution, or airborne particles such as dust, pollen, mold, or yeast. The condition is also a side effect of certain medications.

Most infectious causes occur in association with viral, chlamydial, or bacterial diseases of the eyelids and conjunctiva. The rapid response to corticosteroid therapy suggests a hyperimmune or dyskeratotic mechanism, although this has not been proved.

Symptoms
The keratitis caused by the herpes simplex virus (HSV) typically presents as a unilateral "red eye" with a variable degree of pain or ocular irritation. Photophobia and epiphora are common; however, vision may or may not be affected, depending upon the location and extent of the corneal lesion. You may see a vesicular skin rash and follicular conjunctivitis with the initial infection, but these are less common with recurrent HSV. A more common sign is secondary uveitis.

The symptoms are often very similar to those of conjunctivitis, an inflammation of the conjunctiva, and photophobia. The eye turns very red and there may be sensitivity to light, and the eye may feel uncomfortable. In the later stages of more severe cases, there can be strong pain, loss of vision/blurriness, and pus may form.

Treatment
Antibiotics, antifungals, and antiviral medication will be used to treat the appropriate organism. Broad spectrum antibiotics will be used immediately, but once the lab analysis determines the offending organism, the medication may be changed. Sometimes more than one medication is necessary. It depends upon the infection, but the patient should be clear on how often and how to use the medications.

A sterile, cotton-tipped applicator may be used to gently remove infected tissue and allow the eye to heal more rapidly. Laser surgery is sometimes performed to destroy unhealthy cells, and some severe infections require corneal transplants.