Trachoma: Symptoms, Types, Causes and Treatment

Trachoma remains one of the world’s most impactful but neglected infectious causes of blindness. This ancient disease, rooted in cycles of poverty and poor sanitation, still affects millions, especially in the world’s most vulnerable communities. Understanding trachoma—its symptoms, types, underlying causes, and available treatments—is essential for patients, healthcare professionals, and public health advocates alike. Let’s explore the complex story of trachoma and what can be done to eliminate this preventable cause of blindness.

Symptoms of Trachoma

Trachoma often begins quietly, with symptoms that can be mistaken for a mild eye infection. But as the disease progresses, its impact on vision and quality of life can be profound. Early detection and intervention are critical in preventing lasting damage and blindness.

Symptom	Description	Typical Stage	Source(s)
Eye Discomfort	Mild irritation, redness	Early/Active	4 5
Tearing	Excessive tearing	Early/Active	5
Discharge	Watery or mucous discharge	Early/Active	4 6
Follicles	Small bumps inside eyelid	Early/Active	1 2 4
Papillary Inflammation	Swelling of inner eyelid	Active/Chronic	6
Eyelid Scarring	White lines on inner eyelid	Chronic/Scarring	4 6
Trichiasis	Eyelashes turn inward	Late/Blinding	1 4 5 6
Corneal Opacity	Clouding of cornea (vision loss)	Very Late/Blinding	4 5

Table 1: Key Symptoms of Trachoma

Early Symptoms: The Silent Onset

At first, trachoma may look like any other mild eye infection. Children are the most susceptible, often presenting with:

• Minor eye discomfort or irritation
• Redness of the conjunctiva (inner surface of eyelids)
• Excessive tearing
• Watery or mucous-like discharge

These symptoms are subtle and can easily go unnoticed or mistaken for seasonal allergies or conjunctivitis, especially in endemic areas where eye infections are common 4 5.

Progression: Inflammation and Follicle Formation

As trachoma advances, the inside of the upper eyelid develops small, raised bumps called follicles. Alongside this, the eyelid can become swollen—a process known as papillary inflammation. These changes are key diagnostic features and are often found during community eye health surveys 1 2 4.

Chronic Phase: Scarring and Eyelid Distortion

With repeated infections, chronic inflammation sets in. This leads to:

• Scarring of the inner eyelid, visible as white lines
• Eyelid distortion, which can cause the lashes to turn inward (trichiasis)

Trichiasis is particularly dangerous. Inward-turning lashes repeatedly scratch the surface of the eye, causing pain, further inflammation, and risk of blinding corneal damage 4 5 6.

Final Stage: Vision Loss

Without treatment, the mechanical trauma and continuing infection can cloud the cornea, resulting in irreversible vision loss or blindness. This stage may appear years after repeated infections, often in adulthood, even if transmission of the bacteria has decreased in the community 4.

Types of Trachoma

Trachoma is not a single-stage disease. The World Health Organization (WHO) recognizes a spectrum of clinical forms, each representing a step in the disease’s natural history. Understanding these types is crucial for proper diagnosis and intervention.

Type	Defining Feature	Age Group/Stage	Source(s)
TF (Follicular)	≥5 follicles on upper eyelid	Children/Early	1 2 4
TI (Intense)	Pronounced thickening/inflammation	Children/Progressive	4 6
TS (Scarring)	Scarring of inner eyelid	Adolescents/Adults	4 6
TT (Trichiasis)	Inward-turning eyelashes	Adults/Late	1 4 5 6
CO (Corneal Opacity)	Cornea clouding, vision loss	Adults/Final	4 5

Table 2: WHO-Defined Types of Trachoma

WHO Simplified Grading System

To standardize diagnosis and monitoring, the WHO developed a simplified grading system. The key types include:

• TF: Trachomatous Inflammation—Follicular
  Characterized by at least five follicles (small, whitish bumps) on the upper eyelid’s inner surface. This is most often seen in children under 10 and is the primary indicator used in prevalence surveys 1 2 4.

• TI: Trachomatous Inflammation—Intense
  Marked by pronounced thickening and redness of the upper eyelid. TI represents a more severe, active stage, indicating a high risk of transmission and progression to scarring 4 6.

Chronic and Blinding Stages

• TS: Trachomatous Scarring
  Persistent inflammation leads to scarring (TS) of the conjunctiva. This is often seen in adolescents and young adults, especially those who experienced repeated infections in childhood 4 6.

• TT: Trachomatous Trichiasis
  In this advanced stage, scarring causes the eyelid to turn inward, making eyelashes rub against the cornea. TT is the most important risk factor for blinding complications and is a key indicator for surgical intervention 1 4 5 6.

• CO: Corneal Opacity
  The final, sight-threatening stage. Repeated trauma and infection cloud the cornea, causing irreversible blindness if untreated 4 5.

Clinical and Public Health Implications

Different types require different responses:

• Active stages (TF/TI) signal ongoing transmission and need for community-wide interventions.
• Advanced stages (TS/TT/CO) require surgical and rehabilitative services 1 4.

Causes of Trachoma

At its core, trachoma is an infectious disease—but the story is far more complex, involving environmental, behavioral, and social factors. Understanding the causes is key to breaking the cycle of transmission and guiding effective control strategies.

Cause/Factor	Mechanism/Role	At-risk Groups	Source(s)
Chlamydia trachomatis	Bacterial infection of the conjunctiva	Children, women	2 4 5 6
Repeated Infection	Multiple exposures cause cumulative damage	Children	4 6
Poor Hygiene	Promotes transmission via secretions	Rural communities	1 4 5
Crowded Living	Close contact increases risk	Families/children	1 4 5
Environmental Factors	Dust, flies, limited water access	Rural, poor areas	4 5

Table 3: Key Causes and Risk Factors for Trachoma

The Infectious Agent: Chlamydia trachomatis

Trachoma is caused by specific conjunctival strains of the bacterium Chlamydia trachomatis. This bacterium infects the moist membranes (conjunctiva) lining the eyelids and the eye surface 2 4 5 6.

• C. trachomatis is distinct from the strains causing genital infections, but all belong to the same species 5.
• Infection is often subclinical, especially in early stages, allowing for silent spread within households and communities 4 6.

Repeated Infection and the Disease Cycle

A single infection rarely causes blindness. Instead, trachoma’s damage is cumulative, resulting from repeated infections—often at least 150 episodes over a lifetime are needed to develop the blinding form (trichiasis) 4.

• Children are especially vulnerable, as they are frequently re-infected by family members or neighbors 4 6.
• Each new infection triggers an immune response, which, over time, leads to scarring and eyelid deformation 6.

Transmission: How Trachoma Spreads

The main routes of transmission include:

• Direct Contact: Eye and nose secretions from infected individuals, especially children.
• Indirect Contact: Contaminated towels, clothing, and fingers.
• Flies: Certain species (like Musca sorbens) can transfer infected secretions from one person to another 4 5.

Environmental and Social Determinants

Trachoma flourishes where:

• Water is scarce, making regular face washing difficult.
• Sanitation is poor, allowing for easy spread of secretions and breeding of flies.
• Households are crowded, increasing close contact.
• Women and young girls, as primary caregivers, are at higher risk due to repeated close contact with infected children 1 4 5 6.

These factors explain why trachoma remains common in some of the world’s poorest and most marginalized communities.

Treatment of Trachoma

Trachoma is both preventable and treatable. Modern strategies focus on both individual patient care and population-level disease control. The World Health Organization advocates the “SAFE” strategy—an integrated approach proven to reduce disease burden where fully implemented.

Treatment	Approach/Details	Target Group/Stage	Source(s)
Surgery	For trichiasis to prevent blindness	Adults w/ trichiasis	1 4 10
Antibiotics	Azithromycin (oral, single dose) or tetracycline (topical)	Active trachoma/entire communities	7 8 9 10 11
Facial Cleanliness	Promotion of regular face washing	Children/families	1 4 10
Environmental Improvement	Improved sanitation, water, fly control	Communities	1 4 10

Table 4: Main Treatment and Control Strategies for Trachoma (“SAFE”)

The SAFE Strategy

The backbone of trachoma control is the SAFE strategy:

• Surgery (for trichiasis)
• Antibiotics (to eliminate infection)
• Facial cleanliness (to break transmission)
• Environmental improvement (to sustain control) 1 4 10

Surgery

Surgery is recommended for people with trichiasis—where eyelashes turn inward and threaten the cornea. Timely surgery can prevent further corneal damage and preserve sight 1 4 10.

Antibiotics

• Azithromycin: A single oral dose is highly effective and easy to administer on a community-wide basis. Mass drug administration (MDA) with azithromycin can dramatically reduce infection prevalence and break the chain of transmission 7 8 9 10.
• Tetracycline eye ointment: An alternative, especially where azithromycin is unavailable. Requires six weeks of twice-daily application, which can be difficult for compliance 7 9 10.

Mass antibiotic distribution is recommended in communities where active trachoma prevalence in children is above a certain threshold, often for at least three consecutive years 1 10.

Facial Cleanliness

Regular washing of children’s faces is a simple but powerful intervention, reducing the reservoir of infection and the risk of transmission via secretions and flies 1 4 10.

Environmental Improvement

Sustainable control requires:

• Access to clean water for washing
• Improved sanitation facilities
• Fly control (e.g., waste management, latrine use)

Environmental changes address the root causes, making it possible to achieve lasting elimination 1 4 10.

Effectiveness and Challenges

• Antibiotic treatment has been shown to reduce both clinical signs and bacterial infection. Azithromycin is especially effective, with high compliance and community acceptance 7 8 9 10 11.
• Surgery reduces the risk of further vision loss in those with trichiasis 1 4 10.
• SAFE is most successful when all components are implemented together, adapted to local needs and monitored for impact 1 4 10.

Possible challenges include:

• Ensuring coverage of remote or marginalized populations
• Securing long-term funding and political will
• Monitoring for antibiotic resistance (although this is currently not a major issue for trachoma control) 10 11

Conclusion

Trachoma is a blinding disease with ancient roots and modern solutions. Its story is one of microbial infection, community vulnerability, and the enormous power of public health action. Through coordinated strategies, trachoma can be—and is being—eliminated as a public health problem in many regions.

In summary:

• Trachoma is the world’s leading infectious cause of blindness, beginning with mild symptoms and progressing to severe, irreversible vision loss if untreated 4 5.
• The disease passes through well-defined stages (TF, TI, TS, TT, CO), each requiring different clinical and public health responses 1 4 6.
• It is caused by repeated conjunctival infection with Chlamydia trachomatis, thriving where hygiene, sanitation, and water access are limited 2 4 5 6.
• The WHO’s SAFE strategy—Surgery, Antibiotics, Facial Cleanliness, Environmental improvement—is proven to control and eliminate trachoma when fully implemented 1 4 10.
• Early detection, community engagement, and sustained resources are essential for achieving the goal of a trachoma-free world.

Trachoma’s elimination is within reach. By understanding its symptoms, types, causes, and treatment, we can help ensure that no one loses their sight to this preventable disease ever again.