Related articles: Trachoma
Definition
Trachoma is an infectious disease, caused by the bacterium Chlamydia trachomatis, which affects the conjunctiva resulting in chronic inflammation.
Trachoma is very contagious and is easily transmitted through direct contact with an infected person (mostly from eyes to eyes or from hand to eye). The infection can also occur for the sharing of contaminated personal objects (towels and clothing) or through carriers (flies). If left untreated, trachoma is characterized by progressive exacerbations and remissions that can cause the appearance of scars on the eyelids, trichiasis, visual disturbances and irreversible blindness.
Globally, trachoma is the leading cause of blindness of infectious origin. The causative agent of the disease is endemic in many poor areas of Asia, Africa, Central and South America, Australia and the Middle East.
Most common symptoms and signs *
- Conjunctivitis
- Ocular pain
- Entropion
- Fotofobia
- Eyelid swelling
- Tearing
- Eyes reddened
- Corneal opacity
- itch
- Reduced vision
- Ocular secretion
- trichiasis
- Blurred vision
Further indications
Trachoma usually affects both eyes. Initial symptoms appear after an incubation period of about 7 days and include mild ocular itching, photophobia, eyelid edema, conjunctival hyperemia and lacrimation. Subsequently, numerous whitish follicles develop on the upper tarsal conjunctiva; these gradually increase in size, until they become inflammatory papillae. At this stage, the corneal neovascularization process also begins.
If adequate therapy is not adopted, inflammatory follicles and papillae are replaced by scar tissue with thickening of the eyelid, entropion, obstruction of the tear duct and trichiasis (folding of the eyelashes towards the inside of the eye). In addition to causing pain, trichiasis damages the cornea: the cilia, reversing their orientation, come into contact with the ocular surface and cause further irritation, constitution of the corneal cloth (infiltration and superficial vascularization of the cornea) and scarring. Therefore, the cornea becomes opaque and thickened, and abrasions or ulcers can appear. The progression of the disease can lead to permanent blindness.
The diagnosis is usually clinical and is based on the detection of characteristic signs (eg, follicular hypertrophy, conjunctival scarring and growth of new blood vessels on the cornea).
C. trachomatis can be isolated in culture or identified by PCR and immunofluorescence techniques.
Treatment consists of topical or systemic antibiotics. Generally, azithromycin or, alternatively, doxycycline and tetracycline are used. Better personal hygiene and environmental measures (eg access to drinking water and adequate sanitation) can reduce reinfection. The entropion must be treated surgically.
