Brief Description, Types, Sign and Symptoms, Causes And Treatment Of Bacterial keratitis

Bacterial keratitis is an inflammatory infection of the cornea (the clear, round dome covering the dark colored part of the eye) which is caused by bacteria. 
The most common bacteria involved include: Pseudomonas aeruginosa (found in soil and water) and Staphylococcus aureus (normally live on human skin and on the protective lining inside the body called the mucous membrane).

Bacterial keratitis can either be superficial keratitis or deep keratitis. In Superficial keratitis, the uppermost layers of the cornea are involved and keratitis usually heals with no scar on the cornea surface. In deep keratitis, the deeper corneal layers are affected and a scar may be left after healing. Depending on where this scar is located, it may or may not affect your vision.


Bacterial keratitis can have various causes, some of which include:

• Contact lens wear, especially extended-wear;
• Prolonged use of topical steroids;
• Use of contaminated eye drops, ointments or other eye solutions;
• Recent eye injury or corneal disease;
• Weakened immunity caused by poor nutrition, diabetes or alcoholism.
• Eyelids or tearing problems.

In addition to bacterial keratitis, there are a number of other eye infections that leads to keratitis, some of which include:

1. Fungal keratitis (caused by fungal infection)
2. Viral keratitis (caused by herpes zoster viruses and herpes simplex)
3. Amoebic keratitis (often caused by Acanthamoeba and usually affecting contact lens wearers)
4. Photokeratitis (caused by exposing the eyes to intense ultraviolet radiation, e.g. welder's arc eye or snow blindness).

Symptoms

Symptoms of bacterial keratitis include the following:
•    Often sudden pain in the affected eye.
•    Affected eye is red.
•    Blurred or reduced vision.
•    Increased sensitivity to light (photophobia).
•    Excessive tearing or eye discharge


If you experience any of these symptoms above, especially when they come in a sudden onset, remove your contact lenses (if you are wearing any) and consult your eye doctor immediately. To prevent vision loss, bacterial keratitis treatment must be started right away because if left untreated, it can lead to total and irreversible blindness.


In severe cases, bacterial keratitis may lead to hyphemia (presence of blood in the anterior chamber of the eye), posterior synechiae (adhesion between the posterior surface of the iris and the anterior surface of the crystalline lens) and/or glaucoma.

Treatment

If you are a contact lens wearer, it is very vital to safely handle, clean and store your contact lenses to reduce your risk of developing keratitis.

Bacterial keratitis is often treated with antibiotic drops which are usually put in frequently. Treatment may also involve application of a topical steroid to the eye and may require multiple return visits to the eye doctor. The frequency of antibiotic drops administration should be tapered off according to the clinical course.


Cycloplegic eye drops or ointments maybe applied to reduce pain from ciliary spasm and to prevent the incident of posterior synechiae (adhesion between the posterior surface of the iris and the anterior surface of the crystalline lens).


Wearing of dark goggles (sunshades) may reduce the photophobic symptoms that come with bacterial keratitis. When corneal ulcer is present, vitamin A, C and B-complexes will definitely be of help in re-epithelialization and early healing of the cornea.