Definition

Keratitis is an inflammation of the cornea, the outermost part of the eye that covers the pupil and iris (the colored ring around the pupil). The most common causes of keratitis are infection and injury.

Bacterial, viral, parasitic and fungal infections can cause keratitis. 

Source : Drugs

 

Organ

The part of the eye affected by keratitis is the cornea, which is then inflamed and painful.

 

Bacterial Keratitis

Symptoms

• Reduced vision;
• Pain in the eye (often sudden);
• Increased light sensitivity;
• Tearing;
• Excessive tearing or discharge from your eye. 

 

Causes 

The bacteria usually responsible for this type of keratitis infection are Staphylococcus Aureus and, for contact lens wearers, Pseudomonas Aeruginosa.

Bacterial keratitis can have various causes, including:

• Contact lens use, especially extended-wear lenses;
• Use of contaminated eye medicine or other solution applied to the eye;
• Use of topical steroids;
• Recent corneal disease;
• Trauma or injury;
• Reduced immunity due to diabetes, alcoholism or poor nutrition.

 

Treatment

To accurately diagnose bacterial keratitis eye infection, your ophthalmologist may gently scrape the eye to take a small sample of material and test it for infection. He or she will also discuss your bacterial keratitis symptoms with you. Your ophthalmologist will diagnose whether your keratitis is bacterial keratitis or fungal keratitis.

Bacterial keratitis is usually treated with antibiotic drops and may require multiple return visits to your ophthalmologist. Drops are usually put in frequently. Treatment may also involve a topical steroid applied to the eye.

If you wear contact lenses, it is very important to safely handle, store and clean your lenses to reduce your risk of developing a keratitis infection. Learn how to safely take care of your contact lenses.

If bacterial keratitis is caught and treated early, vision may be preserved. However in severe cases, or if the infection affects the center of the cornea, decreased vision or blindness may result. In some cases corneal transplantation is needed to restore vision.

Source : AAO

 

Herpes Keratitis

Herpes keratitis is a viral infection of the eye caused by the herpes simplex virus (HSV). There are two major types of the virus. Type I is the most common and primarily infects the face, causing the familiar "cold sore" or "fever blister." Type II is the sexually transmitted form of herpes, infecting the genitals.

While both Type I and Type II herpes can spread to the eye and cause infection, Type I is by far the most frequent cause of eye infections. Infection can be transferred to the eye by touching an active lesion (a cold sore or blister) and then your eye.

 

Symptoms

• pain,
• redness,
• blurred vision,
• tearing,
• discharge,
• sensitivity to light.

 

Treatment

Treatment of herpes keratitis depends on its severity. Mild infection is typically treated with topical and sometimes oral antiviral medication. Your ophthalmologist may gently scrape the affected area of the cornea to remove the diseased cells. In case of severe scarring and vision loss, a corneal transplant may be required.

It is very important to consult an ophthalmologist before beginning any treatment, because some medications or eyedrops may actually make the infection worse.

There is no complete cure for herpes; once the virus is in the body, you cannot get rid of it. However, if you develop herpes keratitis, there are some things you can do to help prevent recurring outbreaks:

If you have an active cold sore or blister, avoid touching your eyes.

• Avoid steroid eye drops, as these cause the virus to multiply.
• Stop wearing contact lenses if you keep getting infections.
• See an ophthalmologist immediately if symptoms of ocular herpes return.

Source : AAO

 

Acanthamoeba keratitis

Causes

This infection is caused by a microscopic, free-living ameba (single-celled living organism) called Acanthamoeba. Acanthamoeba causes Acanthamoeba keratitis when it infects the transparent outer covering of the eye called the cornea. Acanthamoeba amebas are very common in nature and can be found in bodies of water (for example, lakes and oceans), soil, and air.

 

Symptoms

The symptoms of Acanthamoeba keratitis can be very similar to the symptoms of other eye infections. These symptoms, which can last for several weeks or months, may include:

• Eye pain
• Eye redness
• Blurred vision
• Sensitivity to light
• Sensation of something in the eye
• Excessive tearing

 

Diagnosis and treatment

Early diagnosis is essential for effective treatment of Acanthamoeba keratitis.

The infection is usually diagnosed by an eye care provider based on symptoms, growth of the Acanthamoeba ameba from a scraping of the eye, and/or seeing the ameba by a process called confocal microscopy.

The infection is treated with one or more prescription medications. An eye care provider can determine the best treatment option for each patient.

 

Images

An eye with non-ulcerative sterile keratitis

Source : Eddie314 at the English language Wikipedia [GFDL or CC-BY-SA-3.0], via Wikimedia Commons