Microbial keratitis is an inflammation of the eye’s cornea. It’s caused by a bacterial infection that most commonly affects people who wear contact lenses. Almost a million patients end up in doctors’ offices and emergency departments each year because of microbial keratitis or contact lens disorders, according to Centers for Disease Control and Prevention estimates.
Left untreated, the infection can lead to corneal scarring and vision loss. But the good news is that microbial keratitis is preventable.
Contact lens–related microbial keratitis is typically caused by improper lens care—poor disinfection practices, an unclean storage case, sleeping with contacts in. One of three bacteria is usually to blame: Pseudomonas aeruginosa, Staphylococcus aureus or Streptococcus pneumoniae. Symptoms of microbial keratitis include eye pain, redness, reduced vision, light sensitivity, excessive tearing, and discharge.
Risk factors for the infection include wearing rigid contact lenses overnight, such as those used to reshape the cornea and correct nearsightedness; storing or rinsing contacts in water instead of lens solution; and using contaminated or used solution. A recent eye injury, corneal disease or a weakened immune system (such as from diabetes) can also increase susceptibility to microbial keratitis.
To prevent infection, follow these simple hygiene basics suggested by Anthony Aldave, M.D., the Walton Li Chair in Cornea and Uveitis at the Stein Eye Institute at UCLA:
• Wash your hands with soap and water and dry them with a clean cloth before handling your contacts.
• Avoid sleeping in your contacts, unless instructed by your eye doctor.
• Avoid wearing your contacts in water, including showers, pools and hot tubs.
• Rub and rinse contacts with only fresh contact lens disinfecting solution, never water or saliva. Ask your doctor to recommend an appropriate lens solution.
• Replace your contact lens case every three months.
• When cleaning your case, empty and dry it thoroughly. Place the case upside down to dry, with the caps off, after each use.
• Replace your contacts as recommended by your eye doctor.
• Schedule regular eye appointments.
Standard treatment, Aldave says, is antibiotic eye drops. In some cases, steroid eye drops may be added for a short time to control inflammation, but your doctor must carefully monitor you for adverse effects, such as increased pressure within the eye, which can lead to glaucoma.
If you have symptoms of keratitis, remove your lenses and seek help quickly; the infection can progress rapidly.
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