Conjunctivitis (viral, non-herpetic)

The CMGs are guidelines on the diagnosis and management of a range of common and rare, but important, eye conditions that present with varying frequency in primary and first contact care.

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Adenovirus (more than 30 serotypes)

  • commonest form of acute infective conjunctivitis
  • spectrum of disease varies from mild to severe
  • two syndromes of adenoviral infection:
    • pharyngoconjunctival fever (not dealt with in this Guideline)
    • epidemic conjunctivitis and keratoconjunctivitis (this Guideline)

Enterovirus 70 (EV70) and Coxsackievirus A24 (CA24v)

  • acute haemorrhagic conjunctivitis (rare epidemics)

Predisposing factors

Recent cold or other upper respiratory tract infection
Low standards of hygiene
Crowded conditions (schools, camps, clinics)
Eye clinics (transmission by clinicians’ fingers, tonometer prisms, etc.)

Symptoms of conjunctivitis (viral, non-herpetic)

Acute onset

  • redness
  • discomfort, usually described as burning or grittiness
  • watering

Eyelids may be stuck together in the morning and have to be bathed open
Often unilateral at first, becoming bilateral, first eye usually more affected
Blurred vision if central cornea involved
Systemic malaise

Signs of conjunctivitis (viral, non-herpetic)

Watery discharge
Conjunctival hyperaemia (may be intense)
Follicles on palpebral conjunctiva, especially upper and lower fornix (if abundant, follicles can produce folds)
Petechial (pin-point) subconjunctival haemorrhages
Pseudomembranes on tarsal conjunctival surfaces (severe cases only)
Pre-auricular lymphadenopathy which may be tender (not present in every case)
Corneal involvement in some cases:

  • punctate epithelial lesions within first two weeks
  • later replaced by sub-epithelial lesions which may persist for months

Differential diagnosis

Other forms of conjunctivitis

  • bacterial
  • chlamydial
  • herpetic (simplex or zoster)
  • allergic

Other causes of acute red eye

  • angle closure glaucoma
  • keratitis
  • anterior uveitis

A point of care dianostic test (AdenoPlus) is available (see NICE Medtech innovation briefing)

Management of conjunctivitis (viral, non-herpetic) by Optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

Non pharmacological

Wash hands carefully before and after examination and clean equipment before next patient
Do not applanate with a re-usable tonometer prism as condition is highly contagious
Advise patient: 

  • condition is normally self-limiting, resolving within one to two weeks
  • condition is highly contagious for family, friends and work colleagues (do not share towels, etc)
  • infection with adenovirus necessitates 2 weeks off work or school
  • cold compresses may give symptomatic relief
  • discontinue contact lens wear in acute phase

Review to monitor for painful or sight-compromising corneal involvement or development of conjunctival pseudomembrane (in either case, refer to ophthalmologist)
(GRADE*: Level of evidence=low, Strength of recommendation=strong)


Antibacterial agents are not effective in viral conditions
Current topical and systemic anti-viral agents also ineffective in adenovirus infection
Artificial tears and lubricating ointments (drops for use during the day, unmedicated ointment for use at bedtime) may relieve symptoms
Topical antihistamines may be used for severe itching
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Management category

B2: alleviation/palliation; normally no referral
A2: first aid measures and emergency referral (same day) if conjunctivitis severe (e.g. presence of pseudomembrane) or if significant keratitis present (e.g. severe pain and/or visual loss)

Possible management by ophthalmologist

Conjunctival swabs for virus isolation and strain identification
Currently available anti-viral medication is ineffective
Topical low dose steroids may be prescribed where sub-epithelial opacities affect vision but this may encourage long-term steroid dependency and is not supported by the evidence base.  Topical steroid may also be indicated in the acute phase where there is conjunctival pseudomembrane formation

Evidence base

*GRADE: Grading of Recommendations Assessment, Development and Evaluation (

Sources of evidence

Azari AA, Barney NP. Conjunctivitis: a systematic review of diagnosis and treatment. JAMA. 2013;310:1721-9

Everitt H, Wormald R, Henshaw K, et al. Viral conjunctivitis. In: Wormald R, Smeeth L, Henshaw K, eds. Evidence Based Ophthalmology. London: BMJ books, 2003

Majeed A, Naeem Z, Khan DA, Ayaz A. Epidemic adenoviral conjunctivitis report of an outbreak in a military garrison and recommendations for its management and prevention. J Pak Med Assoc. 2005;55:273-5 

AdenoPlus point-of-care test for diagnosing adenoviral conjunctivitis. 
NICE Medtech innovation briefing [MIB46] 2015.

Pihos AM. Epidemic keratoconjunctivitis: A review of current concepts in management. J Optom. 2013 Apr; 6(2): 69–74

Skevaki CL, Galani IE, Pararas MV, Giannopoulou KP, Tsakris A. Treatment of viral conjunctivitis with antiviral drugs. Drugs. 2011;71(3):331-47


Lay summary

Viral conjunctivitis is an infection of the eye in which one or both eyes become red and uncomfortable. The condition is not normally serious and in most cases clears up without treatment. It is highly infectious and care needs to be taken to prevent others from becoming infected, for example by not sharing towels.

In terms of treatment, antibiotics are ineffective against viruses and there is no effective anti-viral drug. Usual care involves the control of symptoms using cool compresses applied to the closed eyes, coupled with the use of lubricating eye drops and ointment.

In a small number of cases viral conjunctivitis can lead to the development of small opaque areas within the cornea (the clear window at the front of the eye), which can cause blurred vision. In such cases, and where there is severe inflammation, emergency referral to an ophthalmologist should be arranged.

Conjunctivitis (viral, non-herpetic)
Version 12
Date of search 27.09.18
Date of revision 25.10.18
Date of publication 17.04.19
Date for review 26.09.20
© College of Optometrists

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