Trachoma


– Trachoma is a highly contagious keratoconjunctivitis due to Chlamydia trachomatis. The disease is endemic in the poorest rural areas of Africa, Asia, Central and South America and the Middle East.
– Infection is usually first contracted early in childhood by direct or indirect contact (dirty hands, contaminated towels, flies). In the absence of hygiene and effective treatment, the inflammation intensifies with successive infections, causing scars and deformities on the upper tarsal conjunctiva. The resulting ingrowing eyelashes (trichiasis) cause corneal lesions followed by permanent blindness, usually in adulthood.
– The WHO classifies trachoma into 5 stages. Early diagnosis and treatment of first stages is essential to avoid the development of trichiasis and associated complications.

Clinical features

Several stages can occur simultaneously1,2:

– Stage 1: trachomatous inflammation - follicular (TF)
Presence of five or more follicles in the upper tarsal conjunctiva. Follicles are whitish, grey or yellow elevations, paler than the surrounding conjunctiva.

– Stage 2: trachomatous inflammation - intense (TI)
The upper tarsal conjunctiva is red, rough and thickened. The blood vessels, normally visible, are masked by a diffuse inflammatory infiltration or follicles.

– Stage 3: trachomatous scarring (TS)
Follicles disappear, leaving scars: scars are white lines, bands or patches in the tarsal conjunctiva.

– Stage 4: trachomatous trichiasis (TT)
Due to multiple scars the margin of the eyelid, usually the upper lid, turns inwards (entropion); the eyelashes rub against the cornea and cause ulcerations and chronic inflammation.

– Stage 5: corneal opacity (CO)
Cornea gradually loses its transparency, leading to visual impairment and blindness.

Treatment

– Stages 1 and 2:
• Clean eyes and face several times per day.
• Antibiotic treatment3:
The treatment of choice is azithromycin PO:
Children: 20 mg/kg single dose
Adults: 1 g single dose
Failing the above, 1% tetracycline eye ointment: one application 2 times daily for 6 weeks, or, as a last resort, erythromycin PO: 20 mg/kg (max. 1 g) 2 times daily for 14 days.

– Stage 3: no treatment

– Stage 4: surgical treatment
While waiting for surgery, if regular patient follow-up is possible, taping eyelashes to the eyelid is a palliative measure that can help protect the cornea. In certain cases, this may lead to permanent correction of the trichiasis within a few months.
The method consists in sticking the ingrowing eyelashes to the external eyelid with a thin strip of sticking-plaster, making sure that the eyelid can open and close perfectly. Replace the plaster when it starts to peel off (usually once a week); continue treatment for 3 months.
Note: epilation of ingrowing eyelashes is not recommended since it offers only temporary relief and regrowing eyelashes are more abrasive to the cornea.

– Stage 5: no treatment

Prevention

Cleaning of the eyes, face and hands with clean water reduces direct transmission and the development of secondary bacterial infections.



References

  1. Thylefors B et al. A simple system for the assessment of trachoma and its complications. Bull World Health Organ. 1987;65(4):477–83.
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2491032/ [Accessed 20 April 2021]

  2. Solomon AW et al. The simplified trachoma grading system, amended. Bull World Health Organ. 2020;98(10):698-705. 
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7652564/ [Accessed 20 April 2021]

  3. Evans JR et al. Antibiotics for trachoma. Cochrane Database Syst Rev. 2019 Sep 26;9:CD001860. 
    https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD001860.pub4/full [Accessed 20 April 2021]