KERATITIS

KERATITIS

Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired eyesight, photophobia (light sensitivity), red-eye and a 'gritty' sensation.

Causes

There are two main types of keratitis, depending on what causes it. Keratitis may be classified as either infectious or noninfectious.

Infectious keratitis

Bacteria: Pseudomonas aeruginosa and Staphylococcus aureus are the two most common types of bacteria that cause bacterial keratitis. It mostly develops in people who use contacts improperly.=

Fungi: Fungal keratitis is caused by Aspergillus, Candida, or Fusarium. As with bacterial keratitis, fungal keratitis is most likely to affect those who wear contact lenses. However, it’s also possible to be exposed to these fungi outdoors

Parasites: An organism called Acanthamoeba has become more common in the United States in those wearing contact lenses. The parasite lives outdoors and may be picked up by swimming in a lake, walking in a wooded area, or getting infected water on your contact lenses. This type of infection is called Acanthamoeba keratitis.

Viruses: Viral keratitis is primarily caused by the herpes simplex virus, which progresses from conjunctivitis to keratitis.

Noninfectious keratitis

Possible noninfectious causes of keratitis include:

• eye injury, such as a scratch
• wearing your contacts too long
• using extended-wear contacts
• wearing your contacts while swimming
• living in a warm climate, which increases the risk of plant materials damaging your cornea
• a weakened immune system
• exposure to intense sunlight called photokeratitis

Symptoms

Signs and symptoms of keratitis include:

• Eye redness
• Eye pain
• Excess tears or other discharge from your eye
• Difficulty opening your eyelid because of pain or irritation
• Blurred vision
• Decreased vision
• Sensitivity to light (photophobia)
• A feeling that something is in your eye

Sign

• Lid edema
• ciliary congestion of the conjunctiva

Risk factors

Factors that may increase your risk of keratitis include:

• Contact lenses. Wearing contact lenses — especially sleeping in the lenses —increases your risk of both infectious and noninfectious keratitis. The risk typically stems from wearing them longer than recommended, improper disinfection or wearing contact lenses while swimming.
  Keratitis is more common in people who use extended-wear contacts or wear contacts continuously, than in those who use daily wear contacts and take them out at night.
• Reduced immunity. If your immune system is compromised due to disease or medications, you're at a higher risk of developing keratitis.
• Corticosteroids. The use of corticosteroid eye drops to treat an eye disorder can increase your risk of developing infectious keratitis or worsen existing keratitis.
• Eye injury. If one of your corneas has been damaged from an injury in the past, you may be more vulnerable to developing keratitis.

Keratitis treatment

• antibiotics for bacterial infections
• biocides for parasitic infections
• antifungals for fungal infections
• antivirals for viral infections

Complications

Potential complications of keratitis include:

• Chronic corneal inflammation and scarring
• Chronic or recurrent viral infections of your cornea
• Open sores on your cornea (corneal ulcers)
• Temporary or permanent reduction in your vision
• Blindness

Prevention

Caring for your contact lenses

If you wear contact lenses, proper use, cleaning and disinfecting can help prevent keratitis. Follow these tips:

• Choose daily wear contacts, and take them out before going to sleep.
• Wash, rinse and dry your hands thoroughly before handling your contacts.
• Follow your eye care professional's recommendations for taking care of your lenses.
• Use only sterile products that are made specifically for contact lens care, and use lens care products made for the type of lenses you wear.
• Gently rub the lenses during cleaning to enhance the cleaning performance of the contact lens solutions. Avoid rough handling that might cause your lenses to become scratched.
• Replace your contact lenses as recommended.
• Replace your contact lens case every three to six months.
• Discard the solution in the contact lens case each time you disinfect your lenses. Don't "top off" the old solution that's already in the case.
• Don't wear contact lenses when you go swimming.

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