Introduction
Trachoma is an infection of the eyes by a bacterium Chlamydia trachomatis. It is the leading preventable cause of blindness worldwide and very contagious.
The organism is found in the conjunctival as well as corneal epithelium and is responsible for two different conditions:
- Trachoma (a severe disease)
- Inclusion conjunctivitis (milder)
Trachoma is commonly associated with poverty and unhygienic living conditions.
Clinical features
Acute phase:
- Irritable red eye
- Mucopurulent eye discharge
- Eyelid oedema, pain, photophobia in severe cases
Chronic phase:
- Follicles on tarsal conjunctivae
- Papillae
- Superficial punctate keratitis
End stage:
- Pannus formation on superior cornea
- Corneal scarring
- Eyelid scarring with trichiasis, entropion
- Conjunctival scarring
- Limbal scarring with Herbert’s pits
Differential diagnoses
- Other forms of infective conjunctivitis (especially viral)
- Allergic/vernal conjunctivitis
- Corneal scarring from other diseases
Complications
- Trichiasis
- Entropion
- Corneal scarring
Investigations
- Conjunctival scraping for microscopy
- Immunofluorescence or ELISA test
- Giemsa staining for trachoma inclusion bodies
Drug treatment
Topical:
Tetracycline ointment applied 4 times a day for 6 weeks
Systemic:
Erythromycin, tetracycline (not recommended for young children) or then newer antibiotics e.g. azithromycin as appropriate
Azithromycin
Adult:
- 500 mg orally once daily for 3 days
Child:
- over 6 months: 10 mg/kg (maximum 500 mg) orally once daily for 3 days;
- over 6 months (body weight 15-25 kg) 200 mg once daily for 3 days;
- body weight 26-35 kg: 300 mg once daily for 3 days;
- body weight 36-45kg: 400 mg once daily for 3 days
Surgical treatment
- Indicated for the treatment of trichiasis, entropion, corneal scarring
- Corneal graft, but entropion must be corrected first
Caution and contraindications
- Systemic tetracycline is contraindicated in young children
Prevention
- Improve personal and public hygiene
- Treat the whole community with topical or systemic antibiotics
- Prompt surgery for trichiasis and entropion to prevent blindness from corneal scarring