Case 1: The red-eye


The goal of the case reports is to go through common cases and review important concepts ( from the MDCM objectives).

This case will help you:

  1. Demonstrate basic knowledge of the clinical manifestations of common ophthalmological conditions (1.2.1)

  2. Begin to differentiate between urgent and non-urgent ophthalmological conditions (1.5.1)



ID: 28 year old female currently an electrical engineer.

Past-medical history: none

Past ocular history: myopia - 3 OU

Allergies: Penicillin

Medications: OCP


Patient presents to your walk-in clinic with a 10 days history of bilateral red-eyes. It initially started with her right eye (see clinical photography below) and 3 days later her left eye began to turn red. On further history she reports some tearing and scant crusty discharge mostly when she awakes in the morning.  She reports some rhinorrhea as well, but denies any other symptoms of a upper respiratory tract infection. Her sister also complained of her right eye becoming red. The patient goes on to report that she has mild increased sensitivity to light or  photophobia and her vision is blurrier especially in the afternoon. However, she denies any history of vision loss, pain or history of foreign bodies or trauma.


On Exam (O/E):

VA (with glasses) : OD 20/25-1         OS 20/25+2

IOP (with the tono-pen) :  OD 14       OS 13


Pupils: equal, round and reactive to light. No relative afferent pupillary defect OU

Extra-ocular movements appear normal OU

External exam: you appreciate pre-auricular lymphadenopathy on her

right side


Slit lamp exam (SLE): From external structures to internal structures

Conjunctiva: +++ Follicules on the palpebral conjunctiva OU

and excessive tearing, 3+ conjunctival redness (injection) 

Sclera : white OU

Cornea : Clear

Anterior chamber: Deep and quiet (no cells)

Iris: Within normal limits (WNL)

Lens: Within normal limits (WNL) 

Most likely diagnosis: Adenoviral conjunctivitis


Adenoviral conjunctivitis is the most common cause of conjunctivitis and the prevalence is estimated between 15%-70% of all conjunctivitis worldwide. There are more than 50 types of serotypes identified. The mode of transmission in through hand to eye contact, ocular secretions, respiratory droplets. It is highly contagious, and the risk of transmission has been estimated to be 10-50%. The virus has been found to live on surfaces for over 10 days. The incubation and contamination period are between 5-12 days and 10-14 days, respectively. The acute phase  of severe conjunctivitis can last from 2 to 4 weeks.  It is important that you recognize as soon as possible the signs and symptoms of adenoviral conjunctivitis and install proper hygiene protocols (proper hand washing precautions, no sharing of person equipment and isolated rooms etc)


Adenoviral conjunctivitis is associated with other common clinical entities:

  • Pharyngoconjunctival fever  :

    •  Abrupt onset of high fever

    • Pharyngitis

    • Bilateral conjunctivitis

    • Periarticular lymph node enlargement

  • Epidemic keratoconjunctivitis :

    • Cause by serotypes 8,19,37

    • More severe presentation

    • Watery discharge

    • Hyperemia, chemosis

    • Ipsilateral lymphadenopathy

  • Nonspecific follicular conjunctivitis

    • Simple adenoviral conjunctivitis


Going back to our particular case, two important clues that steer us towards the diagnosis were first it was a bilateral process and second it fit the sequential time course of adenoviral conjunctivitis by beginning in one eye and hoping to the other a few days later. We can also see that her sister was contaminated which leads us more towards an infectious process; especially a viral process.


To review: 


 Risk factors for contamination with adenoviral conjunctivitis include contact with:

  • Contaminated fingers

  • Medical instruments

  • Contaminated swimming pool water

  • Personal items from an infected person


Symptoms include:

  • Redness

  • Irritation

  • Tearing

  • Blurry vision and sensitivity to light


Signs include:

  • Eyelid edema

  • Follicular conjunctivitis

  • Conjunctival edema

  • Hyperemia and conjunctival injection

  • Preauricular lymphadenopathy          

Treatments include:

  • Supportive care

  • Cool compresses and artificial tears for comfort

  • Strict hygiene

  • Staying off work during the contamination period


Complications include:

Patient who develop severe epidemic keratoconjunctivitis can develop conjunctival pseudomembranes or even true membranes, as well as sub-epithelial infiltrates in their cornea which can decrease their vision. This requires treatment with topical steroids prescribed by an ophthalmologist.


Differential diagnosis:

Bacterial conjunctivitis

  • Classically, patient's will present with more purulent discharge which can be copious and thick. This is often seen in newborn babies who become infected. The patient tends to also get worst lid swelling, papillae and chemosis​ (conjunctival edema)

  • Common agents: S. aureus, S. pneumoniae, H.influenzae and M. catarrhalis

  • In neonates or sexually active patients you must consider N.gonorrhoeae and also consider co-treating for chlamydia and treat the partner. 

Allergic conjunctivitis

  • ​Usually have mucous discharges and tends to be more itchy with flare-ups during the summer or spring. ​​
  • On exam they tend to have more papillae and more corneal involvement (i.e. shield ulcer in vernal conjunctivis)

Corneal abrasion or ulcer 


Chemical injury

  • Consider acid or base. Usually have more pain and eye can be white with acid injury. Usually unilateral and associated with more pain and a telling history. 


Blepharitis or dry eye 

  • Often also bilateral but also more of a chronic time course with associated findings on exam of meibomian gland dysfunction and hyperemia of the eyelid margin with more punctate epithelial erosions on the adjacent inferior cornea. Ask for associated systemic findings in dry eye like autoimmune disease or roscea. 


Foreign bodies or trauma 

  • Check for a careful history of a foreign body or trauma especially grinding metal on metal (risk of intra-ocular foreign body) Look closely with the slit lamp for signs of lacerations in all ocular structures or objects embedded in the cornea or any pigmented tissue coming out of the eye with associated collapse of the anterior chamber --> Globe rupture emergency


Angle closure glaucoma

  • Often presents more acutely with significant cornea haze and edema, a mid dilated, shallow anterior chamber and very high intra-ocular pressure (i.e. 35 to 55).  The patient will also be in severe pain with nausea, vomiting and photophobia



Authors : Bouhout Soumaya, Dr. Andre Ali-Ridha, Dr. Discepola



References :


  1. consulted October 2nd  2018

  2. Pihos AM. Epidemic keratoconjunctivitis: A review of current concepts in management. Journal of Optometry. 2013;6(2):69-74. doi:10.1016/j.optom.2012.08.003.


  4. consulted October 2nd  2018

  5. Ehlers, J. P., Shah, C. P., & Wills Eye Hospital (Philadelphia, Pa.). (2008). The Wills eye manual: Office and emergency room diagnosis and treatment of eye disease. Philadelphia: Lippincott Williams & Wilkins.




Approach to conjunctivitis.png
red eye.png
Author : Marco Mayer
Approach to conjunctivitis: 
Image taken from The Wills Eye Mannual 7th edition page 104