What Is Trachoma?

Trachoma is the leading infectious cause of vision loss and blindness worldwide. We review its characteristics and treatment options.

Reviewed and approved by el médico Diego Pereira.

Written by Josberth Johan Benitez Colmenares

Last update: 30 June, 2023

Trachoma, formerly known as Egyptian ophthalmia, is a bacterial infection that affects the eyes. It’s characterized by a roughness and scarring on the inner surface of the eyelids, as well as erosion on the surface of the cornea. In the absence of treatment, these episodes lead to blindness. In fact, the World Health Organization (WHO) considers trachoma to be the main infectious cause of blindness worldwide.

Most of the reported cases are currently concentrated in sub-Saharan Africa, although throughout the 19th century it was a major public health problem in Europe and North America. Blindness caused by trachoma is irreversible, but its progression can be dealt with when caught early. We’ll tell you everything you need to know about it.

Causes of trachoma

Trachoma is a bacterial infection of the eyes caused by Chlamydia trachomatis, primarily by serotypes A, B, and C. Others, such as Chlamydophila psittaci and Chlamydophila pneumoniae, have also been implicated, although infections by these are less common. The pathogen is transmitted from infected people to uninfected people through different channels. The most important are the following:

• Direct eye-to-eye transmission during close contact
• Transmission through hand-eye contact
• Indirect transmission on fomites
• Transmission by flies that seek the eye

Evidence suggests that most cases are reported in overcrowded and unsanitary conditions. It is known that once the chlamydial infection occurs on the ocular surface, a chronic inflammatory reaction is produced. This is characterized by the manifestation of lymphocytic, monocytic, plasma cell, and macrophage infiltrates. Several types are distinguished according to their evolution:

• Follicular trachoma
• Intense trachomatous inflammation
• Trachomatous scarring
• Trachomatous trichiasis
• Corneal opacity

Recurrent inflammation processes are those that lead to secondary ulcers and, if they aren’t treated, blindness. Researchers have found that trachoma is more common in children than in adults, although episodes of blindness don’t occur until late childhood, puberty, adolescence, or early adulthood (if not treated, as we have already mentioned). Most cases today are reported in Africa, the Middle East, the Indian subcontinent, Southeast Asia, and South America.

Trachoma symptoms

The first symptoms appear between 5 and 12 days after infection with the bacteria. As we have already mentioned, they are characterized by a progression that initially manifests as conjunctivitis, and which, in the absence of treatment, can lead to blindness. Here is a typical clinical picture:

• Itching and irritation of the eyes and eyelids (mild, but then increases in intensity)
• Eye discharge with the presence of mucus or pus
• Inflammation of the eyelids
• Sensitivity to direct light
• Eye redness
• Pain on the ocular surface
• Loss of vision (in its last stage)

It’s important to note that most lesions are concentrated in the upper eyelid, and that both eyes are always affected. Eyelid deformity, corneal opacity, and entropion may also occur.

Diagnosis of trachoma

Most of the time the diagnosis is made based on clinical observation, considering that in areas where it’s endemic there isn’t always access to detection equipment. The specialist will assess the symptoms of the infection and, in case of doubt, can perform a culture or order nucleic acid amplification tests and immunofluorescence techniques.

If a person with symptoms of conjunctivitis has traveled to an endemic region, the possibility of Chlamydia trachomatis infection should be considered. During the evaluation, the healing inside the upper eyelid and the growth of new blood vessels in the cornea will be evaluated to establish how advanced the infection is.

Treatment options

Treatment during the early stages is imperative in order to avoid long-term complications of the infection. Topical and systemic antibiotics are the best option when dealing with the condition. In the first case, 1% tetracycline ointment can be used in both eyes twice a day for 6 weeks.

Regarding systemic treatment, experts recommend a single dose of azithromycin 20 mg/kg (maximum 1 g). Available alternatives are erythromycin 500 mg twice daily for 14 days or doxycycline 100 mg twice daily for 10 days. Both drugs are not recommended for pregnant or lactating women, or children under 8 years of age.

The most advanced cases require surgical intervention, in principle, to maintain complete closure of the eyelid and to alleviate entropion and trichiasis. Severe scarring can be addressed with the help of a corneal transplant. Handwashing, facial washing, and improvements in household sanitation are recommended to prevent re-infection.