This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.  Read our Cookies Policy.
Close
Eye News
  • Features
    • Close
    • Features
    • Allied Professions
    • Humanitarian
    • Interviews
    • AI & Oculomics
    • Ophthalmology
    • Optometry
    • Podcast videos
    • Supplements
  • Education
    • Close
    • Education
    • Learning Curve
    • Quiz
    • Top Tips
    • Trainees
    • Medico-Legal
    • The Truth Behind The Headlines
    • Case Reports
    • Pete's Bogus Journey
  • Reviews
    • Close
    • Reviews
    • Book Reviews
    • Journal Reviews
    • What's trending?
    • Tech Reviews
    • My Top Five
    • The Culture Section
  • Events
  • News
  • Product Guide
  • Industry News
  • Contact us
    • Close
    • Contact us
    • Write for Eye News
  • Home
  • Features
  • Ophthalmology
  • Decoding the red eye

Decoding the red eye
By Vaishnavi Menon and Varshini Manoharan

15 February 2021 | Vaishnavi Menon, Varshini Manoharan | EYE - Cornea
Share This

 

 

 

 

Red eye, or hyperaemia, is one of the most common presentations to primary care [1] and the emergency department [2]. However, despite this the underlying cause is often misdiagnosed which can lead to severe, sight-threatening conditions being missed [1].

Thorough evaluation with an appropriate history and examination can help to distinguish the sight-threatening from the benign red eye. In this article, we aim to discuss common causes of red eye and provide a comprehensive approach to decoding the red eye.

What are the causes?

Redness of the eye can be unilateral or bilateral. It is the primary sign of ocular inflammation usually occurring due to engorgement of superficial blood vessels or can occur when a blood vessel ruptures [3]. Most of the cases tend to be benign as they are self-limiting or require minimal intervention. Only a handful of cases go on to be serious and in need of urgent referral.

There are a myriad of causes that lead to a red eye. The following is a red eye sieve to help consider the possible differential diagnoses [4]:

 

History and examination

As with all presentations, good history and examination is key to an accurate diagnosis and initiation of appropriate management. A thorough history is essential as the presence of a red eye may be associated with an underlying systemic disease. Therefore, a complete history including a systems review, past medical, drug, family and social history is necessary.

In order to determine the underlying cause for the red eye, there are two key questions to ask in the history of the presenting complaint: 1) Is there any pain? 2) Is there any loss of vision? Other important features to enquire about include whether the symptoms are unilateral or bilateral, the duration of symptoms, presence of photophobia, recent eye trauma or surgery, contact with anyone unwell, whether there is a history of contact lens use and, if so, contact lens hygiene.

A stepwise examination approach incorporates a thorough inspection of the structures of the eye as well as eye function [5,6].

 

Red flags [7]

NICE recommends considering a same day ophthalmology referral if the following features are present, as they may be indicative of serious underlying pathology::

  • Reduced vision or visual acuity
  • Deep pain in the eye or tenderness on palpation of the globe
  • Photophobia
  • Unequal pupil or abnormal pupil reactions
  • High velocity or chemical injury
  • Contact lens use
  • Fluorescein staining
  • Neonatal conjunctivitis – conjunctivitis in the infant in the first 28 days of life

Diagnosing the red eye [8,9]

 

 

 

Please click the PDFs to see two further tables connected to this article:
The acute non-painful red eye [10,11]
The acute painful red eye [10,11]

 

 

 

TAKE HOME MESSAGE
  • Presentations of red eye are usually benign and can often be managed in the community, however, it is important not to miss a sight-threatening diagnosis!
  • Golden questions: Is there any pain? Is there any loss of vision? Presence of these symptoms can be associated with more serious pathology.
  • The sight threatening causes of a red eye warranting immediate ophthalmology referral include:
    o Acute angle closure glaucoma 
    o Corneal ulcer / abscess 
    o Ocular trauma
    o Chemical injuries 
    o Endophthalmitis
    o Scleritis
    o Uveitis
  • All chemical eye injuries are potentially blinding injuries.
  • Abrasions may be missed if fluorescein is not used.
  • If in doubt of the aetiology of a red eye, refer to ophthalmology!

 

 

References

1. Kilduff C, Lois C. Red eyes and red-flags: improving ophthalmic assessment and referral in primary care. BMJ Quality Improvement Reports 2016;5(1):u211608.w4680.
2. Gilani C, Yang A, Yonkers M, Boysen-Osborn M. Differentiating Urgent and Emergent Causes of Acute Red Eye for the Emergency Physician. Western Journal of Emergency Medicine 2017;18(3):509-17.
3. Frings A, Geerling G, Schargus M. Red Eye: A Guide for Non-specialists. Deutsches Aerzteblatt Online 2017.
4. Olver J, Cassidy L, Jutley G, Crawley L: Ophthalmology at a Glance. Wiley Blackwell; 2005.
5. Sibal N, Tyagi A. Red eye: what's the diagnosis? Guidelines in practice 2018:
https://www.guidelinesinpractice.co.uk/
eye-ear-nose-and-throat/red-eye-whats
-the-diagnosis/454421.article

6. Allen R, Harper R: Basic Ophthalmology. San Francisco, Calif: American Academy of Ophthalmology; 2016.
7. Scenario: Management of red eye. NICE 2020:
https://cks.nice.org.uk/
topics/red-eye/management/
management-of-red-eye/

8. Cronau H, Kankanala R, Mauger T. Diagnosis and management of red eye in primary care. American Family Physician 2010;81(2):137-44.
9. Worthing J, Tse A. The Red Eye. Core EM 2019:
https://coreem.net/core/the-red-eye/
10. Dennison A, Murray P: Oxford Handbook of Ophthalmology. 4th ed. Oxford University Press; 2018.
11. Khaw P, Shah P, Elkington A: ABC of Eyes. Wiley; 2013.

(All links last accessed February 2021)

 

 

COMMENTS ARE WELCOME

Share This
Vaishnavi Menon
CONTRIBUTOR
Vaishnavi Menon

Queen Elizabeth Hospital, Birmingham, UK.

View Full Profile
Varshini Manoharan
CONTRIBUTOR
Varshini Manoharan

Bradford Royal Infirmary, Bradford, UK.

View Full Profile
Additional: Table1
The acute non-painful red eye.pdf
Additional: Table 2
The acute painful red eye.pdf
Download the full article
Download Article

Top Of Page

9 Gayfield Square, 
Edinburgh EH1 3NT, UK.

Call: +44 (0)131 557 4184
www.pinpoint-scotland.com

WEBSITE DETAILS
  • Cookie Policy
  • Data Protection Notice
  • Privacy Policy
  • Terms and Conditions
ABOUT US
  • Who we are
  • Register
  • Contact us
  • Contributors
  • Company Awards
DIGITAL ISSUES/GUIDELINES
  • Digital issues - Library
  • Supplements - Library
  • Guidelines
Accreditations
IPSO_FLAG_TEAL 2025.png cpdcertified.png

Pinpoint Scotland Ltd (Registered in Scotland No. SC068684) | © 2025 - Website by Gecko Agency