Bacterial keratitis is an infection of the cornea (the clear, round dome covering the eye’s iris and pupil) that causes pain, reduced vision, light sensitivity and tearing or discharge from your eye. Resulting from infection from contact lens use or from injury to the eye, bacterial keratitis usually develops very quickly, and if left untreated, can cause blindness. The bacteria usually responsible for this type of keratitis infection are Staphylococcus Aureus and, for contact lens wearers, Pseudomonas Aeruginosa.
Superficial keratitis involves the uppermost layers of the cornea. When this form of keratitis has healed, there is usually no scar on the cornea.Deep keratitis affects deeper corneal layers. There can be a scar left after healing which may or may not affect your vision, depending on where the scar is located.
In addition to bacterial keratitis, there are a number of other types of keratitis, some of which include:
- Amoebic keratitis (usually affecting contact lens wearers, it is often caused by Acanthamoeba);
- Fungal keratitis (infection with fungi);
- Viral keratitis (usually caused by herpes simplex and herpes zoster viruses);
- Photokeratitis (due to intense ultraviolet radiation exposure, e.g. snow blindness or welder’s arc eye).
Symptoms of bacterial keratitis may include:
- Reduced vision;
- Pain in the eye (often sudden);
- Increased light sensitivity;
- Excessive tearing or discharge from your eye.
If you experience any of these symptoms, especially if they come on suddenly, call your ophthalmologist right away. If not taken care of, a keratitis eye infection can lead to blindness. Bacterial keratitis treatment must be started right away to prevent vision loss.
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.