(Egyptian Ophthalmia; Granular Conjunctivitis)
Trachoma is a chronic conjunctivitis caused by Chlamydia trachomatis and is characterized by progressive exacerbations and remissions. It is the leading cause of preventable blindness worldwide. Initial symptoms are conjunctival hyperemia, eyelid edema, photophobia, and lacrimation. Later, corneal neovascularization and scarring of the conjunctiva, cornea, and eyelids occur. Diagnosis is usually clinical. Treatment is with topical or systemic antibiotics.
Trachoma is endemic in poverty-stricken parts of North Africa, the Middle East, the Indian subcontinent, Australia, and Southeast Asia. The causative organism is Chlamydia trachomatis(serotypes A, B, Ba, and C). In the US, trachoma is rare, occurring occasionally among Native Americans and immigrants. The disease occurs mainly in children, particularly those between the ages of 3 and 6. Older children and adults are much less susceptible because of increased immunity and better personal hygiene. Trachoma is highly contagious in its early stages and is transmitted by eye-to-eye contact, hand-to-eye contact, eye-seeking flies, or the sharing of contaminated articles (eg, towels, handkerchiefs, eye makeup).
Trachoma usually affects both eyes. Four stages are described.
In stage 1, after an incubation period of about 7 days, conjunctival hyperemia, eyelid edema, photophobia, and lacrimation gradually appear, usually bilaterally.
In stage 2, after 7 to 10 days, small follicles develop in the upper tarsal conjunctiva and gradually increase in size and number for 3 or 4 wk. Inflammatory papillae appear on the upper tarsal conjunctiva. Corneal neovascularization begins, with invasion of the upper half of the cornea by loops of vessels from the limbus (called pannus formation). The phase of acute follicular/papillary hypertrophy and corneal neovascularization may last from several months to > 1 yr, depending on response to therapy.
In stage 3, the follicles and papillae gradually shrink and are replaced by bands of scar tissue. Without treatment, corneal scarring eventually occurs. The entire cornea may ultimately be involved, reducing vision. Secondary bacterial infection is common, contributing to scarring and disease progression.
In stage 4, the conjunctival scar tissue often causes entropion (often with trichiasis) and lacrimal duct obstruction. Entropion and trichiasislead to further corneal scarring and neovascularization. The corneal epithelium becomes dull and thickened, and lacrimation is decreased. Small corneal ulcers may appear at the site of peripheral corneal infiltrates, stimulating further neovascularization.
Rarely, corneal neovascularization regresses completely without treatment, and corneal transparency is restored. With treatment and healing, the conjunctiva becomes smooth and grayish white. Impaired vision or blindness occurs in about 5% of people with trachoma.
Diagnosis of trachoma is usually clinical because testing is rarely available in endemic areas. Lymphoid follicles on the tarsal plate or along the corneal limbus, linear conjunctival scarring, and corneal pannus are considered diagnostic in the appropriate clinical setting.
If the diagnosis is uncertain, C. trachomatis can be isolated in culture or identified by PCR and immunofluorescence techniques. In the early stage, minute basophilic cytoplasmic inclusion bodies within conjunctival epithelial cells in Giemsa-stained conjunctival scrapings differentiate trachoma from nonchlamydial conjunctivitis. Inclusion bodies are also found in adult inclusion conjunctivitis, but the setting and developing clinical picture distinguish it from trachoma. Palpebral vernal conjunctivitis appears similar to trachoma in its follicular hypertrophic stage, but symptoms are different, milky flat-topped papillae are present, and eosinophils (not basophilic inclusion bodies) are found in the scrapings.
For individual or sporadic cases of trachoma, azithromycin 20 mg/kg (maximum 1 g) po as a single dose is 78% effective. Alternatives are doxycycline 100 mg bid or tetracycline 250 mg qid for 4 wk. In hyperendemic areas, tetracycline or erythromycin ophthalmic ointment applied bid for 5 consecutive days each month for 6 mo has been effective as treatment and prophylaxis. Endemic trachoma has been dramatically reduced by using community-wide oral azithromycin in a single dose or in repeated doses. Reinfection due to re-exposure is common among endemic areas.
The World Health Organization has endorsed a 4 step program for control of trachoma in endemic areas. This program is known as SAFE:
Surgery to correct eyelid deformities (eg, entropion and trichiaisis) that place patients at risk of blindness
Antibiotics to treat individual patients and mass drug administration to reduce the disease burden in the community
Facial cleanliness to reduce transmission from infected individuals
Environmental improvement (eg, access to potable water and improved sanitation) to reduce transmission of disease and reinfection of patients
Trachoma is a chronic, exacerbating, and remitting chlamydial conjunctivitis that is common among children ages 3 through 6 in certain poverty-stricken areas worldwide.
Manifestations develop in stages and include conjunctivitis, formation of tarsal follicles, corneal neovascularization, and scarring.
About 5% of patients develop decreased vision or blindness; trachoma is the leading cause of blindness worldwide.
Diagnosis is usually clinical, but standard methods to detect chlamydia can be done when available.
Treatment is usually with oral azithromycin.
For endemic areas, the World Health Organization also advocates corrective surgery, emphasizing facial cleanliness, and environmental interventions to reduce transmission.