What is microbial keratitis?
This is a serious condition in which the cornea (the clear window of the eye) becomes infected. The usual cause is contact lens wear, but infection of the cornea can also result from exposure of the eye (for example if the eyelids are not blinking normally), loss of sensation in the eye surface, injury or surgery, lack of tears (dry eye), and in people whose immune system is not functioning properly. The usual cause is bacterial (i.e. caused by a common germ) but some cases are due to fungal infection.
Microbial keratitis is a very serious condition. It usually begins suddenly with redness and pain in one eye. The eye waters and there may be a discharge. Light may hurt the eye, making it difficult to open. The vision of the eye may be blurred.
The optometrist will usually observe an area in the cornea where the clear tissue has been turned cloudy by infection. There may be an ulcer on the surface. The inflammation extends into the chamber at the front of the eye also.
How is microbial keratitis managed?
Microbial keratitis is a sight-threatening emergency. In the case of small ulcers with a low risk of sight-threatening complications the optometrist may initiate antibiotic therapy but more serious cases will need to be referred on the same day to the ophthalmologist. The ophthalmologist will take specimens from the ulcer and begin treatment with antibiotic eye drops. These will need to be put into the eye very frequently. The patient will most likely be admitted to hospital so that treatment can continue day and night. If the infection is caused by a fungus, the treatment will usually be with anti-fungal eye drops and tablets.
When the infection is controlled, steroid eye drops may be added. If the infection was contact lens related, the patient will be given advice on whether it is safe to wear lenses again.
