Describe bacterial conjunctivitis with its types and management.

Acute Mucopurulent Conjunctivitis

• The commonest form of bacterial conjunctivitis, and one of the commonest of all ocular conditions. Organisms: staphylococcus aureus (the commonest overall), Streptococcus pneumoniae, haemophilus influenzae (particularly in children, and often with otitis media), and Moraxella
• Symptoms — discomfort and a foreign-body or "sand in the eye" sensation rather than true pain; redness; discharge; and sticking together of the lids on waking, which is characteristic and is often the presenting complaint
• The coloured haloes — patients may describe rainbow haloes around lights, from the prismatic effect of mucus in the tear film. They disappear when the discharge is cleared by blinking or irrigation — the "FICK'S sign" — which distinguishes them from the persistent haloes of angle-closure glaucoma. This is a genuinely useful bedside discrimination

Acute Purulent (hyperacute) Conjunctivitis

• The organism is neisseria gonorrhoeae (and rarely N. Meningitidis). In adults it is transmitted by autoinoculation from the genital tract, and it is an ophthalmic emergency
• Why it is an emergency — because neisseria can penetrate an intact corneal epithelium. Almost every other organism requires a breach; this one does not, so a corneal ulcer and perforation can develop within 24 to 48 hours in an eye that was normal the day before
• Features — explosive onset over hours; copious thick yellow pus, which wells out as soon as the lids are parted and reaccumulates immediately; gross lid oedema such that the lids may be impossible to open; severe chemosis, sometimes with the conjunctiva prolapsing between the lids; a tender preauricular node; and pain

Membranous, Angular and Chronic Forms

Summary of the Bacterial Conjunctivitides

Applied Aspects

• Treat hyperacute purulent conjunctivitis as an emergency with systemic ceftriaxone and hourly irrigation; the cornea can perforate within two days
• Use Fick’s sign to separate haloes; haloes that clear on blinking or irrigation are mucus, and haloes that persist are corneal oedema and may be angle closure
• Never patch a discharging eye, and never give a steroid without knowing the diagnosis; both convert a self-limiting illness into a corneal disaster
• Look for a cause in chronic conjunctivitis — blepharitis, dacryocystitis, a retained foreign body, an ingrowing lash or uncorrected refractive error — since it is a symptom rather than a diagnosis
• Distinguish a true from a pseudo-membrane by whether it bleeds; a bleeding, adherent membrane means diphtheria until proved otherwise and the child needs antitoxin