Overview

It often starts so mildly in early childhood that nobody notices, a bit of redness and irritation in the eye that clears up and comes back many times over the years. It is often only decades later, sometimes in someone’s thirties or forties, that the real damage becomes visible, and by then, some of it can no longer be undone.

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Key Fact

Trachoma is the world’s leading infectious cause of blindness, yet the infection itself is easily cleared with a single dose of antibiotic. It is years of repeated, often unnoticed reinfection in childhood, not any single episode, that eventually causes the lasting damage.

Warning

An eyelash rubbing against the eye, or a cloudy patch developing over the cornea, are signs that trachoma has caused lasting damage and need prompt assessment by an eye care provider to prevent further vision loss.

AT A GLANCE

Disease Summary

Category Infectious Disease

Cause Chlamydia trachomatis, a bacterium that infects the eye

Transmission Direct contact with eye or nose discharge, contaminated hands, clothing, or bedding, and flies that have been in contact with discharge

Body System Eyes

Preventable Yes

Curable Yes

Symptoms

Redness and Irritation

The eye may appear red and feel irritated, similar to a mild case of conjunctivitis.

Watery Eyes or Discharge

Discharge from the eyes or nose is common during active infection and is also how the infection spreads to others.

Swollen Eyelids

Mild swelling of the eyelids can occur during active infection.

Mild Sensitivity to Light

Some discomfort in bright light can accompany the irritation and swelling.

Eyelashes Turning Inward

Eyelashes that rub against the eyeball, known as trichiasis, cause constant pain and can scratch the cornea with every blink.

Cloudy or Scarred Cornea

Visible cloudiness over the coloured part of the eye can indicate corneal scarring, a leading cause of trachoma-related blindness.

Scarring on the Inner Eyelid

Visible white lines, bands, or sheets on the inner surface of the upper eyelid indicate scarring from repeated past infection.

Worsening or Permanent Vision Loss

Progressive difficulty seeing can indicate the cornea has been permanently damaged.

Diagnosis

Eyelid Examination

A healthcare worker examines the inside of the upper eyelid, gently turned outward, for follicles, inflammation, or scarring, the basis of the standard grading system used worldwide.

Trichiasis Assessment

A close examination checks whether any eyelashes are touching the surface of the eye.

Laboratory Testing

PCR testing can confirm active infection with the bacterium, though diagnosis in endemic communities is usually made through examination alone.

Important

Trachoma is diagnosed through a simple, standardised eye examination that can be performed by trained health workers in the community, using a widely adopted grading system rather than requiring laboratory equipment.

Laboratory Tests

Eyelid Examination and Clinical Grading

Uses the WHO simplified grading system (TF, TI, TS, TT, CO) to classify the stage of disease based on visible signs.

PCR Testing

Confirms active Chlamydia trachomatis infection, more often used for research and surveillance than routine individual diagnosis.

Slit-Lamp Examination

Allows closer assessment of corneal involvement in more advanced cases.

Laboratory Note

Because trachoma is diagnosed through examination rather than a blood test, community screening programmes rely on training health workers to recognise the standard clinical signs consistently.

Treatment

Antibiotic Treatment

Azithromycin clears active infection effectively and is distributed through mass drug administration programmes in affected communities.

Surgery for Trichiasis

Corrects inward-turning eyelashes to stop them from further damaging the cornea. It prevents further harm but cannot reverse vision already lost.

Treatment Note

Antibiotics can clear an active infection effectively, but they cannot undo scarring or vision loss that has already occurred from past infections. This is why early treatment and preventing reinfection in childhood matter so much.

Prevention

Support antibiotic treatment programmes

Mass distribution of a single dose of azithromycin in affected communities clears infection and reduces transmission.

Practise facial cleanliness, especially in children

Regularly washing children’s faces removes the eye and nose discharge that spreads the infection.

Improve access to water and sanitation

Better access to clean water for washing, and to sanitation facilities, reduces the environmental conditions that allow trachoma to spread.

Support surgical treatment for trichiasis

Corrective surgery for in-turned eyelashes prevents further damage to the eye in people with advanced disease.

Prevention Note

These four measures together are known as the SAFE strategy, Surgery, Antibiotics, Facial cleanliness, and Environmental improvement, the World Health Organization’s global framework for eliminating trachoma as a public health problem.

Risk Factors

Higher Risk of Infection

These groups are more frequently exposed to trachoma in endemic communities.

Young children, who are the main reservoir of infection in endemic areas
Women, who are blinded up to four times more often than men, likely due to closer contact with infected children

Environmental Risk Factors

Conditions that make transmission more likely within a community.

Limited access to clean water and sanitation
Crowded households
Presence of flies that spread eye and nose discharge

Geographic Risk

Where someone lives significantly affects their risk of exposure.

Living in one of the remaining countries where trachoma is a recognised public health problem, mostly in poorer, rural areas of Africa and parts of Asia and the Middle East

Risk Note

Trachoma is closely tied to living conditions rather than any individual behaviour. Improving community-wide access to water, sanitation, and hygiene is often more effective than addressing individual cases alone.

Complications

Trichiasis

Repeated infection can scar the inner eyelid enough that eyelashes turn inward and rub against the eye with every blink.

Corneal Scarring

Constant friction from in-turned eyelashes can permanently cloud the cornea.

Irreversible Blindness

Advanced corneal scarring is a leading cause of preventable blindness worldwide.

Complication Note

These complications develop from years of repeated infection, usually starting in early childhood, which is why breaking the cycle of reinfection matters more than treating any single episode.

When to Seek Medical Care

Eyelashes Rubbing Against the Eye

This needs prompt assessment for corrective surgery to prevent further damage to the cornea.

Cloudy or Scarred Appearance of the Eye

A visible change in the clarity of the eye’s surface should be assessed by an eye care provider.

Persistent Eye Redness or Discharge in a Child

Ongoing symptoms, especially in areas where trachoma is common, are worth having checked, even if they seem minor.

Progressive Difficulty Seeing

New or worsening vision loss should be evaluated promptly, since some damage from trachoma cannot be reversed once it occurs.

Emergency Advice

Because trachoma often develops slowly and painlessly at first, regular eye checks in endemic communities, especially for children, matter as much as responding to obvious symptoms.

Prognosis

Excellent for Active Infection

A single dose of antibiotic effectively clears active infection before lasting damage occurs.

Cumulative Risk With Repeated Infection

Years of repeated infection, most often starting in early childhood, are what eventually cause scarring and vision loss.

Vision Loss Is Usually Permanent

Once the cornea has been damaged by trichiasis, resulting blindness or visual impairment is difficult to reverse, which is why prevention matters more than late treatment.

Prognosis Note

Trachoma is one of the clearest examples of a disease where prevention and early treatment offer an excellent outcome, but delayed care can lead to permanent, irreversible harm.

Differential Diagnosis

Bacterial or Viral Conjunctivitis

Causes similar redness and discharge but does not lead to the same pattern of scarring seen in trachoma.

Allergic Conjunctivitis

Can cause similar redness and irritation but is linked to allergies rather than infection, and does not scar the eyelid.

Vitamin A Deficiency

Another significant cause of preventable blindness in some of the same regions, though it affects the eye differently.

Clinical Note

In areas where trachoma is common, eyelid examination using the standard grading system helps distinguish it from other causes of eye redness or vision loss.

References

World Health Organization (WHO)

World Health Organization fact sheet on trachoma transmission, symptoms, distribution, and the SAFE elimination strategy.

WHO — Diagnosis of Trachoma

WHO’s detailed guidance on the simplified grading system used to diagnose and stage trachoma.

StatPearls (NCBI Bookshelf)

Clinical reference detailing the trachoma grading system, diagnosis, and management.

Frequently Asked Questions

Is trachoma contagious?

Yes. It spreads through direct contact with eye or nose discharge, contaminated hands, clothing, or bedding, and flies that have touched the discharge of an infected person.

Can trachoma be cured?

Active infection is easily cured with a single dose of antibiotic. However, scarring or vision loss caused by repeated past infections cannot be reversed, which is why early treatment matters.

Why does trachoma affect women more than men?

Women are blinded by trachoma up to four times more often than men, likely because of their closer, more frequent contact with infected children.

How is trachoma being controlled globally?

Through the World Health Organization’s SAFE strategy: Surgery for advanced cases, Antibiotics to clear infection, Facial cleanliness, and Environmental improvements like better water and sanitation access.

Trachoma