Microsporidial keratoconjunctivitis

Causative agent

Keratoconjunctivitis is an inflammation of the cornea and conjunctiva. Cornea is the transparent front part of the eye whereas conjunctiva lines the inner eyelids and covers the white part of the eyeball. Microsporidial infection is one of the potential causes of keratoconjunctivitis.

Microsporidia are a group of parasites which may cause systemic diseases or localised diseases such as keratoconjunctivitis. Microsporidial keratoconjunctivitis was previously more common in immunocompromised persons, but in recent years it has been increasingly reported in healthy individuals. Risk factors may include having eye trauma, wearing contact lenses, using steroid eye drops and being exposed to unclean water, soil or mud.

Clinical features

Clinical symptoms include foreign body sensation, eye pain, redness and occasionally visual blurring. Some affected persons may experience intolerance to light, tearing, swelling of eyelid, and itchiness. Diagnosis is made by ocular surface scraping and staining.

Mode of transmission

Spores of Microsporidia can be found in the environment and soil. Keratoconjunctivitis can occur when unclean water, soil or mud enters the eyes. It has been associated with sports held in muddy fields, e.g. rugby. 

It has not been reported that microsporidial keratoconjunctivitis can be transmitted from person to person.

Incubation period

It is usually 2 to 30 days.

Management

It can be treated with antimicrobial eye drops or oral medication.

Prevention

Avoid playing on very muddy or waterlogged pitches for sports involving contact with soil or mud. If this cannot be avoided, players are advised to wash their faces and eyes thoroughly and immediately afterwards; they should also use different towels for the face and body after engaging in such sports. Members of the public, who have engaged in sports that involve contact with soil or mud, are advised to seek early medical advice if they experience the symptoms.

Improper lens hygiene practice, such as wearing the lens overnight, smoking and wearing the lens continuously for a long time had been reported previously to be associated with increased risk of contact lens-related microbial keratitis.  Contact lens wearers should take heed of the health advice below:

1. Regularly have your eyes checked by eye care professionals.
2. Remove the contact lens whenever you feel discomfort (e.g. redness, pain, tearing or blurred vision) and seek medical advice promptly if symptoms persist despite the contact lenses have been taken off.
3. Never share contact lenses.
4. When using contact lens solution, follow the manufacturer’s instructions for use.
5. Keep all accessories used for cleansing and disinfecting contact lenses (e.g. contact lens storage case) clean and replace them regularly.

To know more about contact lenses and tips on using contact lens solution, please refer to the following websites: https://www.mdd.gov.hk/filemanager/common/information-publication/Know%20More%20About%20Contact%20Lenses_Eng.pdf and https://www.mdd.gov.hk/filemanager/common/information-publication/Tips%20on%20Use%20of%20Contact%20Lens%20Solution.pdf