BASICS

DESCRIPTION

• A blinding infectious condition currently found in mostly undeveloped countries

• Consists of an active inflammatory stage in childhood followed by scarring sequelae in adulthood

EPIDEMIOLOGY

Incidence

Incidence varies widely by geographic area

(1)

• 1.2 billion people live in endemic areas in Africa, Middle East, southern Asia, India, Australia and the Pacific Islands

• 48.5% active trachoma concentrated in 5 countries: Ethiopia, India, Nigeria, Sudan, and Guinea.

• 50% of the global burden of trichiasis is concentrated in only 3 countries: China, Ethiopia, and Sudan.

• Active form affects 40.6 million people

• 8.1 million people have trichiasis

• Accounts for ∼3% of world’s blindness

RISK FACTORS

• Endemic areas

• Poverty

• Crowded living conditions

• Poor water supply

• Host immunity

• Active stage: Children Ages 2–5

• Late stage: Women

• Transmission:

– Direct contact (eye-to-eye)

– Indirect contact (shared clothes)

– Eye seeking (synanthropic) muscoid fly

– Coughing or sneezing

GENERAL PREVENTION

• Improved personal hygiene

• Improved environmental sanitation

PATHOPHYSIOLOGY

• Bacterial cytoplasmic inclusions infect conjunctival epithelial cells.

• Chronic conjunctival inflammation causes tarsal scarring, which causes lid deformities and trichiasis.

• Recurrent infectious keratitis secondary to exposure and trichiasis

• End stage occurs with corneal scarring

ETIOLOGY

Recurrent ocular infections with Chlamydia trachomatis (serotypes A, B, Ba, and C)

COMMONLY ASSOCIATED CONDITIONS

• Dry eyes

• Concurrent infection with Hemophilus influenzae conjunctivitis may cause more severe course.

DIAGNOSIS

HISTORY

• Acute stage: asymptomatic, tearing, discharge, itching, foreign body sensation, and hyperemia

• Late stage: foreign body sensation, tearing, photophobia, and decreased vision

PHYSICAL EXAM

• Grading system (2):

• TF (trachomatous inflammation-follicular): follicles (≥5 of at least 0.5 mm diameter)

• TI (trachomatous inflammation-intense): inflammatory thickening of the tarsal conjunctiva obscuring half of normal conjunctival vessels

• TS (trachomatous scarring): white lines (Arlt’s lines), bands or sheets of scarring of tarsal conjunctiva

• TT (trachomatous trichiasis): ≥1 eyelash(es) rubbing eyeball

• CO (corneal opacity): corneal opacity obscuring pupil margin

• Corneal vascularization/pannus

• Herbert’s pits: Shallow limbal depressions, which are old ruptured follicles

• Entropion

DIAGNOSTIC TESTS & INTERPRETATION

Lab

Conjunctival scraping sent for:

• Polymerase chain reaction (PCR)

• Direct fluorescein-labeled monoclonal antibody (direct fluorescent antibody [DFA]) assay and enzyme immunoassay (EIA) of conjunctival smears

• Giemsa cytology

Pathological Findings

• Chlamydial inclusions in conjunctival epithelial cells

• Lymphoid follicles

• Loss of goblet cells

• Squamous cell metaplasia

• Subepithelial fibrous membrane formation

DIFFERENTIAL DIAGNOSIS

• Active phase:

– Viral (e.g., adenoviral, HSV, VZV)

– Bacterial (Staph aureus, Moraxella)

– Medicamentosa/toxicity

– Molluscum contagiosum

• Late stage:

– Viral (e.g., adenoviral, HSV, VZV)

– Bacterial (Corynebacterium)

– Ocular cicatricial pemphigoid

– Stevens–Johnson syndrome

– Chemical injury

TREATMENT

MEDICATION

First Line

• SAFE strategy (3)[A]:

– S = Surgery

– A = antibiotics

– F = facial cleanliness

– E = environmental improvement

• Active, infectious disease (4)[A]:

– Azithromycin: Children: 20 mg/kg oral single dose; Adults: 1 g oral single dose (1)[A]

– Doxycycline: 100 mg b.i.d for 7 days

– Tetracycline: 15 mg/kg/day for 14 days

• Late disease (5)[B]: Correction of eyelid deformities (bilamellar tarsal rotation procedure)

• Corneal opacity: Corneal transplantation (following lid procedure)

Second Line

Tetracycline ointment b.i.d for 3–6 days every month for 6-month course

ADDITIONAL TREATMENT

General Measures

• Education on the importance of facial cleanliness and hygiene

• Improved water supplies (e.g., water provision program, hand-dug wells, rainwater harvesting)

• Improved sanitation (e.g., household pit latrines)

Issues for Referral

Referral to health system capable of eyelid repair/reconstruction is critical

SURGERY/OTHER PROCEDURES

• Eyelid surgery

• Corneal transplantation: Poor prognosis if continued lid abnormalities or if corneal vascularization is present

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

• Single, annual, high-coverage mass dose of oral azithromycin can interrupt the transmission of trachoma and also reduces childhood mortality in areas where trachoma is moderately prevalent (<35% in children; ref. 6, 7)

• Repeated biannual treatments in hyperendemic areas (>50% children) is probably needed for elimination (8).

PATIENT EDUCATION

• Hygiene education

• Medication compliance education

PROGNOSIS

• Approximately 20–45% of patients with recurrent active trachoma will develop late scarring

• Women and individuals with age >40 more likely to have scarring

COMPLICATIONS

Corneal blindness

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