AKT · Ophthalmology/Orbit & infectionlow yield

Trachoma

Chronic conjunctival infection by Chlamydia trachomatis (serovars A–C)

Overview

Chronic keratoconjunctivitis from ocular Chlamydia trachomatis (serovars A–C), spread by flies and close contact in endemic areas with poor sanitation — the leading INFECTIOUS cause of blindness worldwide. Repeated infection scars the conjunctiva (Arlt line), causing cicatricial entropion and trichiasis that abrade the cornea, leading to opacification and blindness. Controlled with the WHO SAFE strategy.

Recognise

Recurrent follicular conjunctivitis in childhood in an endemic area; foreign-body sensation, discharge
Tarsal conjunctival follicles → scarring (Arlt line) → entropion + trichiasis (in-turned lashes) → corneal abrasion/opacity
Herbert pits (limbal follicle scars); blindness from corneal scarring in adults

Red flags

Trichiasis with lashes touching the cornea → urgent lid surgery to prevent corneal opacification/blindness

Differentials & how to tell them apart

Other bacterial/viral conjunctivitisacute and self-limiting without the chronic scarring/trichiasis or endemic context

Adult inclusion (chlamydial) conjunctivitisserovars D–K, sexually transmitted, no blinding cicatrisation

Vernal keratoconjunctivitisitch-dominant atopic disease with giant papillae

Investigations

Clinical (WHO simplified grading: TF, TI, TS, TT, CO). Chlamydia NAAT/PCR where available.

Management

Azithromycin (WHO SAFE strategy); surgery for trichiasis

1WHO SAFE strategy: Surgery for trichiasis, Antibiotics (azithromycin), Facial cleanliness, Environmental improvement (sanitation/water/fly control).Gate: Trichiasis (in-turned lashes abrading the cornea) needs lid surgery to prevent corneal opacification and irreversible blindness — antibiotics alone do not undo scarring
2Community-wide azithromycin mass treatment; lid-rotation surgery for trichiasis; manage corneal opacity (graft) in established blindness.

Azithromycin (single oral dose) — antibiotic arm of WHO SAFE — mass drug administration in endemic communities; tetracycline ointment alternative

Key points

Endemic-area childhood follicular conjunctivitis → scarring → entropion/trichiasis → corneal blindness. Remember SAFE. It is the world's leading infectious cause of blindness.

Monitor & prognosis

Community grading/surveillance; post-surgical recurrence of trichiasis.

Preventable/treatable early; blinding once corneal scarring is established.

Source: WHO trachoma (SAFE) guidance