Signs and Symptoms of Trachoma
Trachoma presents as a chronic conjunctivitis in children with recurrent infection, progressing to cicatricial disease with trichiasis and corneal opacification in adults, ultimately leading to blindness if untreated.
Active Trachoma (Childhood Presentation)
The infectious stage of trachoma primarily affects children and is characterized by:
- Recurrent conjunctival inflammation that is often subclinical or minimally symptomatic, requiring at least 150 infection episodes over a lifetime to precipitate later complications 1
- Chronic follicular conjunctivitis of the upper tarsal conjunctiva caused by Chlamydia trachomatis serovars A, B, and C 1, 2
- Prolonged or severe inflammatory episodes in a subset of children, which are significant risk factors for subsequent scarring 3
- Generally mild or absent symptoms during active infection, making detection challenging in endemic areas 1
Cicatricial Trachoma (Adult Presentation)
The blinding stage develops years after childhood infections have ceased:
- Conjunctival scarring that develops from repeated inflammatory episodes and progressively worsens even without detectable active infection 2, 3
- Entropion (inward turning of the eyelid) resulting from scar tissue contraction 2
- Trichiasis (in-turning eyelashes that contact the ocular surface), causing pain and mechanical trauma to the cornea 2
- Increased bacterial superinfection occurs in 37% of eyes with trichiasis compared to 7% of normal eyes, which may drive further inflammation and scarring 4
- Corneal opacification develops from chronic mechanical trauma and secondary bacterial infection, ultimately causing blindness 2, 4
Transmission and Epidemiology
- Highly contagious through direct or indirect contact with eye, nose, or throat secretions, as well as via hands, fomites, and flies 5, 6
- Affects the poorest communities in low-income countries, particularly sub-Saharan Africa, with 1.8 million people worldwide going blind from the disease as of 2021 1
- Disease progression occurs in two distinct phases: an infectious-inflammatory childhood disease and a non-communicable cicatricial adult disease that requires different clinical responses 1
Critical Clinical Pearls
- Blindness can appear decades after transmission has ceased in a community, making early intervention crucial 1
- Corneal examination with fluorescein staining should always be performed to detect early corneal involvement 6
- The disease is largely asymptomatic during the infectious stage, requiring active screening in endemic areas rather than relying on symptomatic presentation 1
- Trichiasis severity correlates with bacterial infection risk, suggesting that secondary infection contributes to progressive scarring and corneal damage 4