Definition

Trachoma is an ocular infection caused by the bacterium Chlamydia trachomatis. It is highly contagious and can spread through contact with an infected individual's eyes, eyelids, nasal discharge, or throat, as well as through contaminated objects like handkerchiefs. 

Early symptoms include mild itchiness and irritation of the eyes and eyelids, followed by swelling and discharge from the eyelids. If untreated, trachoma can lead to blindness. 

Trachoma remains the leading cause of preventable blindness globally, with most cases occurring in impoverished regions of Africa, accounting for around 85% of cases. In endemic areas, the infection rate among children under five can exceed 60%. Early intervention can prevent complications.

Causes

Trachoma is caused by the bacterium Chlamydia trachomatis, which is also responsible for the sexually transmitted infection chlamydia. Transmission occurs through contact with ocular or nasal secretions from an infected person, and can be facilitated by hands, clothing, towels, and insects. In developing countries, the Musca sorbens fly serves as a vector for trachoma transmission.

Risk Factor

Several factors can increase the risk of contracting trachoma:

• Densely populated living conditions. Higher population density increases the risk of infection and spread of trachoma.
• Poor hygiene. Inadequate sanitation, insufficient water access, and lack of personal hygiene practices, such as keeping the face and hands clean, facilitate the spread of trachoma.
• Age (4-6 years). In endemic regions, children aged 4-6 years are most commonly affected.
• Female gender. In certain areas, women are 2-6 times more likely to contract trachoma than men, likely due to increased contact with children, the primary transmitters of the infection.
• Presence of Musca sorbens flies. Living in areas with high fly populations increases susceptibility to infection.

Symptoms

Trachoma symptoms typically affect both eyes and include:

• Mild itchiness and irritation of the eyes and eyelids
• Mucus and/or pus discharge from the eyes
• Swollen eyelids
• Increased light sensitivity (photophobia)
• Eye pain
• Redness of the eyes
• Vision disturbances or loss

Young children are particularly vulnerable to infection. However, trachoma generally progresses slowly, with severe symptoms potentially emerging in adulthood.

There are five phases of trachoma development:

1. Follicular inflammation. The initial stage, marked by the appearance of follicles (small lumps containing white blood cells) on the inside of the upper eyelid.
2. Severe inflammation. Highly contagious phase of trachoma with significant eye irritation and thickening or swelling of the upper eyelids.
3. Scar tissue formation on the eyelids. Repeated infections cause scarring on the inner eyelid, visible as white lines upon close examination. This phase can lead to entropion (inward turning of the eyelid).
4. Trichiasis. Condition where eyelashes grow inward towards the eyeball, caused by the altered shape of the scarred inner eyelid, leading to corneal abrasion.
5. Corneal clouding. Continuous inflammation, exacerbated by eyelash scratches, can result in corneal opacity.

Severe trachoma symptoms are more prevalent in the upper eyelid than the lower eyelid. Without adequate treatment, infections initiated in childhood can persist into adulthood.

Diagnosis

Trachoma is diagnosed based on a patient's symptoms, medical history, results of physical examination, and diagnostic tests. Diagnostic tests may include sending samples of eye fluid to a laboratory for bacterial analysis. However, such laboratory tests are not always accessible in regions with high trachoma prevalence.

Management

The treatment and management of trachoma depends on the stage of the disease.

Medication Treatments

In the early stages, antibiotic treatments can cure the infection. Doctors may prescribe tetracycline eye ointment or oral azithromycin. Azithromycin is generally more effective than tetracycline but is more costly.

The World Health Organization (WHO) recommends administering antibiotics to entire communities when over 10% of children have contracted trachoma. This approach aims to treat those exposed to the infection and reduce its spread.

Surgery

Advanced trachoma, particularly with eyelid deformities, may require surgical intervention. Eyelid correction surgery involves making an incision in the scar tissue of the eyelid and rotating the eyelashes outward, away from the cornea. This is done to prevent further scarring and vision loss.

In cases where the cornea becomes sufficiently cloudy to affect vision, a corneal transplant may be considered. In some conditions, eyelash removal through shaving may also be performed repeatedly to prevent them from scratching the eye membrane.

Complications

Early detection and antibiotic treatments can effectively manage a single trachoma infection. However, recurrent infections can lead to complications such as:

• Scar tissue formation on the inner eyelid
• Eyelid deformities, including inward folding of the eyelids (entropion) or ingrown eyelashes (trichiasis), which can scratch the cornea
• Clouding of the cornea
• Partial or complete vision loss

Prevention

Reinfection is possible even after antibiotic treatment or surgery. To prevent this from occurring, ensure that family members or cohabitants living in the same space are checked and treated if they have trachoma.

Trachoma is prevalent globally, especially in Africa, Asia, Latin America, the Middle East, and the Pacific Rim. Maintaining cleanliness is crucial if you currently reside in areas with high trachoma incidence. Good hygiene practices include:

• Washing face and hands regularly to interrupt the cycle of recurring infections
• Controlling fly populations to reduce infection transmission sources
• Proper waste management to decrease fly breeding grounds
• Increasing access to clean water to improve hygiene

Although there is no vaccine for trachoma yet, other preventive measures can be taken. The WHO has developed the SAFE strategy to eliminate trachoma, aiming for eradication by 2020, although this goal has not been fully achieved. The SAFE strategy includes:

• Surgery to treat advanced trachoma
• Antibiotics to treat and prevent infections
• Facial cleanliness to maintain hygiene
• Environmental improvements to enhance sanitation and control flies

Trachoma is a contagious infection. Early treatment of trachoma can prevent serious infections.

When to See a Doctor?

Consult a doctor if you or a family member experience symptoms such as itchy eyes, eye irritation, or eye discharge, particularly if you are currently residing in or having recently traveled to a trachoma-endemic area.

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