Conjunctivitis (viral, non-herpetic)


Adenoviral conjunctivitis is the most common form of acute infective conjunctivitis, accounting for up to 75% of cases

  • adenoviruses are highly contagious pathogens (over 50 serotypes)
  • spectrum of disease varies from mild to severe
  • two syndromes of adenoviral infection:
    • epidemic conjunctivitis and keratoconjunctivitis (EKC) (this Guideline)
      • most cases affect adults aged 20 to 40 years
    • pharyngoconjunctival fever (not dealt with in this Guideline)

Less common causes of non-herpetic viral conjunctivitis

  • Enterovirus 70 (EV70) and Coxsackievirus A24 (CA24v)
    • acute haemorrhagic conjunctivitis (rare epidemics)
  • Molluscum contagiosum (see separate Clinical Management Guideline)
  • SARS-CoV-2 coronavirus
    • conjunctivitis is a rare manifestation of COVID-19 disease

Predisposing factors

Infection may be preceded by ‘flu-like symptoms

Low standards of hygiene

Outbreaks can occur in the general population, especially in crowded conditions (schools, camps), in hospital environments (especially ophthalmological units, and neonatal intensive care units) and in nursing homes

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

Symptoms of EKC usually appear within 14 days of exposure and typically last 7 to 21 days

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) and chemosis

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

Other causes of acute red eye

A point of care diagnostic test (AdenoPlus) is available (see NICE Medtech innovation briefing) [MIB46] 2015.

NB Poor sensitivity (<50%) compared to PCR reference standard; specificity >90%

Management 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)

If COVID-19 disease suspected, refer to current College advice:


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 steroid may be indicated in the acute phase where there is conjunctival pseudomembrane formation

Topical steroids are sometimes used during the acute phase, however there is insufficient evidence to support their use in the treatment of sub-epithelial opacities

Topical ciclosporin (off-licence use)

Evidence base

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

Sources of evidence

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

Jhanji V, Chan TC, Li EY, Agarwal K, Vajpayee RB. Adenoviral keratoconjunctivitis. Surv Ophthalmol. 2015;60(5):435-43

Labib BA, Minhas BK, Chigbu DI. Management of Adenoviral Keratoconjunctivitis: Challenges and Solutions. Clin Ophthalmol. 2020;14:837-852

Lawrenson JG, Buckley RJ. COVID-19 and the Eye (Guest Editorial). Ophthal Physiol Opt 2020 (in press)

Meyer-Rüsenberg B, Loderstädt U, Richard G, Kaulfers PM, Gesser C: Epidemic Keratoconjunctivitis—the cur- rent situation and recommendations for prevention and treatment. Dtsch Arztebl Int 2011; 108(27): 475–80

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

Varu DM, Rhee MK, Akpek EK, Amescua G, Farid M, Garcia-Ferrer FJ, Lin A, Musch DC, Mah FS, Dunn SP; American Academy of Ophthalmology Preferred Practice Pattern Cornea and External Disease Panel. Conjunctivitis Preferred Practice Pattern. Ophthalmology. 2019;126(1):P94-P169

Plain language 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 is seen, rarely, in people with COVID-19 disease.

Conjunctivitis (viral, non-herpetic)
Version 13
Date of search 12.04.20
Date of revision 26.05.20
Date of publication 23.06.20
Date for review 11.04.22
© College of Optometrists

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