Bacterial Conjunctivitis: Causes, Symptoms, Signals and Treatment

It is one of the conditions that make up the great spectrum of eye diseases.

Bacterial conjunctivitis is distinguished by wateriness and involuntary secretion of the eye area, significantly hindering its functions.

Bacterial infection of the conjunctiva, usually occurs due to:

  • Staphylococcus species.
  • Stenococcus pneumonia.
  • Haemophilus influenzae.
  • Moraxella catarrhalis.


Studies have shown that among the population most affected by bacterial conjunctivitis, it is children and the elderly that have a higher risk of bacterial conjunctivitis.

Bacterial conjunctivitis in the first 28 days of life is a serious condition that must be referred urgently to the ophthalmologist.

  • Contamination of the conjunctival surface.
  • Trauma superficial.
  • Use of contact lenses (infection by NB can be Gram -ve).
  • Secondary to viral conjunctivitis.
  • Recent infection by the upper respiratory tract in cold.
  • Diabetes (or another disease that compromises the immune system).
  • Steroids (systemic or topical, which compromise ocular resistance to infection).
  • Blepharitis (or other chronic ocular inflammation).


Acute start of:

  • Redness.
  • Upset, usually described as burning or roughness.
  • Discharge (may cause temporary blurred vision).
  • Formation of scabs on the eyelids (often joined after sleep and may have to bathe).
  • Generally bilateral: one eye can be affected before the other (one or two days).


  • Cover crusting.
  • Purulent or mucopurulent discharge.
  • Conjunctival hyperemia: maximum in fornices.
  • The tarsal conjunctiva may show a mild papillary reaction.
  • Cornea: usually there is no involvement (occasionally SPK, mainly in the lower third of the cornea). If the cornea is important, consider a gonococcal infection.
  • Preauricular lymphadenopathy: usually absent.
  • Differential diagnosis

Other forms of conjunctivitis

  • Epidemic keratoconjunctivitis (eg, adenovirus).
  • Herpes (simple or zoster).
  • Chlamydia infection.
  • Allergy.
  • Other causes of acute red eye.
  • Closed angle glaucoma.
  • Infectious keratitis.
  • Anterior uveitis.

Management by optometrist

The professionals must recognize their limitations and, if necessary, seek more advice or refer the patient to another side.

DEGREE: The level of evidence and the strength of the recommendation are always related to the immediately preceding statements

Non-pharmacological treatment

It often resolves in 5-7 days without treatment

Bathe / clean the eyelids with lint or cotton moistened in sterile saline or boiled water (cooled) to remove the scab

GRADE *: Level of evidence = low, Strength of recommendation = strong

Inform the patient that the condition is contagious (do not share towels, etc.)


Treatment with topical antibiotics can always improve short-term results and make the patient less infectious to others around him / her.

Alternatives include the following: chloramphenicol 0.5% eye drop, chloramphenicol 1% ointment, azithromycin 1.5% eye drop, fusidic acid 1% viscous eye drops.

This recommendation is based on the conclusions of a Cochrane review (Sheikh and Hurwitz 2012) that included successful trials in primary and secondary care, and since then one of the ways to reduce and eradicate the condition in question.

However, a meta-analysis of individual patients from studies based exclusively on primary care found only a marginal benefit of antibiotics over placebo.

It was found that patients with purulent discharge or mild gravity of the red eye benefited most from antibiotic treatment

Users of contact lenses diagnosed with bacterial conjunctivitis should be treated with a topical antibiotic effective against Gram -ve organisms, p. a quinolone such as levofloxacin or moxifloxacin. Contact lenses should not be used during the treatment period.

Possible management by ophthalmologist

Not all patients respond in the same way to the treatment of bacterial conjunctivitis. This for innumerable reasons, ranging from congenital to environmental aspects.

Therefore, if it is the case that the treated patient is resistant to treatment or recurrent, the attending physician may apply: conjunctival swabs taken for microscopy and culture and / or PCR analysis or, failing that, change the medication and apply treatments with other antibiotics, depending on the results of the culture.