This article is the first of two articles about traumatic eye injuries. This article covers the relevant anatomy, history, examination and emergency sight-threatening pathologies to enable you to refer to ophthalmology specialists. The second is called Common Traumatic Pathologies and covers injuries that are important to identify but are less of an emergency.

Anatomy 

Ocular

There are 3 layers of the eye:

1. External fibrous layer – cornea and sclera 
2. Middle vascular layer – choroid, ciliary body and iris 
3. Internal layer – retina

The lens separates the anterior and posterior structures of the eye:

Figure 1: Garrity 2022

Periocular

Eyelids

• The tarsal plate shapes the eyelid margin and pulls the eyelid close to the surface of the eye 
• Canalicular system – drains tears from the ocular surface into the nasopharynx 
• Orbital septum – separates the pre- and post-septal regions 

Importance: penetrating injury into the post-septal space can involve vital structures. 

Bony orbit 

Seven bones form the lateral and medial walls, orbital roof and floor. Importance: the medial wall is thin and most easily fractured.

Figure 2: Teach Me Anatomy, The Bony Orbit

The Orbital Compartment

Contents:

• Extraocular muscles 
• Retro-orbital fat 
• Ophthalmic artery
• Superior and inferior orbital veins 
• Optic nerve 

Importance: Trauma and haemorrhage can push on the structures within the orbital compartment leading to orbital compartment syndrome (OCS)

Classification of injury 

Open globe injury – full thickness injury through all the layers of the eye (from the air outside, through the cornea/sclera and into the centre of the eye). If caused by blunt trauma it is an open globe rupture, if caused by a sharp object it is an open globe laceration. Importance: open globe laceration may leave behind an intra-ocular foreign body.

Closed globe injury – no full thickness injury. Can be broken down into 2 subgroups: lamellar which has a partial thickness defect or contusion if there is no eye wall wound.

Laceration subgroups:

1. Penetrating injury – entrance wound but no exit wound
2. Perforating injury – entrance and exit wounds 
3. Intra-ocular foreign body – retained foreign object within the eye, entrance wound only

Important point: Post-traumatic/bacterial endophthalmitis is a sight-threatening condition that occurs in 8% of penetrating trauma cases. Refer to Red Eye article for further information. 

Key Points of History and Examination

History taking 

• When did the injury happen
• Was it witnessed
• Method and speed of insult to the eye 
• Were any visual changes noticed soon after the injury
• Have any treatments been given (e.g. irrigation)
• Were safety goggles being worn
• Recent activities: fireworks, cleaning, cooking, gardening, sports
• Ocular history and medical history including the use of anticoagulants

Examination

• Visual acuities
  • Red reflex
  • Cornea (using fluorescein)
  • Pupils and relative afferent pupillary defect (RAPD) – see below
  • Conjunctiva
  • Range of movement
  • Any lid lacerations/ burns
  • Orbital bony rim
  • Other examinations e.g. neuro may be relevant depending on the type of injury, contact lens removal 

Important point: If you suspect open globe injury or IOFB avoid examination that will apply pressure to the eye, avoid placing any medication or diagnostic eye drops and do not remove any protruding foreign bodies. 

RAPD

Figure 3 – Stanford Medicine 2022 

RAPD is a sign where pupils react differently when light is shone into one eye at a time using the swinging flashlight test. This sign is due to unilateral disease of the retina or optic nerve. 

Sight Threatening Conditions in the Emergency Department

Open globe injury

Key signs without needing a slit lamp:

• Prolapse of intraocular contents (e.g. iris or ciliary body)
• Severe 360-degree subconjunctival haemorrhage and/or chemosis
• Teardrop pupil pointing towards the corneal injury
• Motility defect

Key signs needing a slit lamp:

• Flat, shallow or “deflated” looking anterior chamber
• Intraocular or protruding foreign body
• New or asymmetric cataract; dislocated lens material
• Positive Seidel test (put a dye (fluorescein 10%) on the surface of the eye and look for a source of dilution from fluid leaking out of the eye from a wound)

Figure 4: Teardrop pupil with the tip pointing toward the corneal injury. This is commonly seen in open globe injury. (Serrano et al. 2013)

Key aspects of management:

• Immediate referral for specialist ophthalmology review – urgent surgical repair, ideally within 24h of injury
• Orbital CT non-contrast 
• Keep NBM, treat nausea and prevent vomiting 
• Analgesia
• IV antibiotics as per trust protocol 
• Head of bed elevated to 30 degrees 

Chemical injuries

Refer to chemical injuries article

Orbital compartment syndrome 

Please refer to the Orbital Compartment Syndrome article 

Foreign bodies

Please refer to the Foreign  Body article 

Traumatic hyphaema 

Key aspects of referral:

• Collection of blood between the cornea and the iris (the anterior chamber) with a fluid level which may cover all or part of the iris and pupil
• Commonly due to a tear in the iris which damages a blood vessel
• History often includes squash injuries and clotting disorders
• Symptoms: pain, photophobia, cloudy or blocked vision
• Commonly confused with subconjunctival haemorrhage which only shows blood in the white of the eye and is not painful

Figure 5: Patel et al. 2021

Key aspects of management:

• Check eye pressure if confident and open globe injury ruled out (see information above)
• Shield the eye
• Raise the head of the bed to allow the blood to drain
• If the patient has a bleeding disorder, sickle cell disease or is anticoagulated discuss with haematology
• Analgesia – topical (0.5% tetracaine or 0.5% proparacaine drops) with additional opiates if required

Important: Do not use ketamine for sedation (emesis common which can increase intraocular pressure) or NSAIDs for pain relief (platelet inhibition)

Vitreous haemorrhage

Bleeding into the vitreous cavity may indicate retinal tear or detachment. 

Features:

• Reduced visual acuity 
• Black spots, cob webs or floaters
• Red reflex may be absent in the affected eye 

Key aspects of management:

• Urgent referral to ophthalmology 
• CT head if have a history of head trauma 

Retinal trauma 

May result in partial or full loss of vision. There are multiple types of retinal trauma:

1. Acute retinal break – may complain of flashes, floaters or spots. May require laser therapy within 24-72h for repair. 
2. Retinal detachment – may complain of flashes, floaters, “shadow” or “curtain” disruption of vision, loss of vision. Detachment requires surgical repair, the urgency of which is determined by the location of the detachment.
3. Purtscher retinopathy – sudden reduction in vision with superficial retinal haemorrhages or cotton wool spots following trauma to the legs, chest or head without direct eye injury. 
4. Commotio retinae – retinal oedema which shows retinal whitening with normal vessels on ophthalmoscopy. Typically resolves without intervention.  

All of the above conditions require urgent ophthalmology review.

Optic nerve injury

Symptoms:

• Reduced visual acuity 
• Red saturation or reduced colour vision 
• Afferent pupillary defect 

Key aspects of management:

• Urgent referral to ophthalmology
• CT orbit
• Treat the underlying cause 

Periocular injuries

• Injuries to the face around the eye can impair eyelid closure, leading to chronic corneal exposure. 

Key aspects of management:

• QDS lubricating eye ointment 
• Treat any pathology caused by the head trauma
• Once stable should be reviewed by ophthalmology specialist  

General Management Points if You Suspect a Serious Ocular Trauma

• Keep patient NBM
• Cover eye with eye shield or galipot 
• Tetanus immunisation if required
• IV analgesia/ antibiotics if a dirty wound
• CT head and orbits
• Refer to Ophthalmology

Written by Dr Sarah O’Beirne (FY3)

Corrections, additions & checking by Miss Emily Stedman (ST6 in Ophthalmology) & Ms Jennifer Tan (Consultant Ophthalmologist)

References

Ameri, Al-Zubidi & Veidani (2022) Relative Afferent Pupillary Defect. EyeWiki, American Academy of Ophthalmology. Accessed 11.10.22 <https://eyewiki.aao.org/Relative_Afferent_Pupillary_Defect>

Gardiner (2022) Overview of eye injuries in the emergency department. UpToDate. < https://www.uptodate.com/contents/overview-of-eye-injuries-in-the-emergency-department>

Garrity (2022) Structure and Function of the Eyes. MSD Manual Customer Version. < https://www.msdmanuals.com/home/eye-disorders/biology-of-the-eyes/structure-and-function-of-the-eyes>

Huffman (2022) What is hyphema? American Academy of Ophthalmology. Accessed on 14.09.22 <https://www.aao.org/eye-health/diseases/what-is-hyphema>

Kanski and Bowling (2013) Synopsis of Clinical Ophthalmology, Third Edition

Kaur et al. (2020) Red Eye. Mind the Bleep. Accessed on 27.09.22 < https://www.mindthebleep.com/red-eye/>

Lippincott. How to assess whether a globe is ruptured. Moran Core. Accessed on 14.09.22 <https://morancore.utah.edu/basic-ophthalmology-review/how-to-assess-whether-a-globe-is-ruptured/#:~:text=Suggestive%20signs%3A,out%20injury%20and%20for%20comparison>

Patel et al. (2021) Hyphema. EyeWiki, American Academy of Ophthalmology. Accessed 27.09.22 < https://eyewiki.aao.org/Hyphema>

Patel et al. (2021) Ocular trauma: acute evaluation, cataract, glaucoma. EyeWiki, American Academy of Ophthalmology. Accessed 14.09.22 <https://eyewiki.aao.org/Ocular_Trauma:_Acute_Evaluation,_Cataract,_Glaucoma>

Serrano et al. (2013) Traumatic Eye Injury Management Principles for the Prehospital Setting. Journal of Emergency Medical Services. Accessed on 14.09.22 <https://www.jems.com/patient-care/traumatic-eye-injury-management-principl-0/>

Stanford Medicine (2022) Pupillary Responses. Accessed on 08.11.22 < https://stanfordmedicine25.stanford.edu/the25/pupillary.html>

Teach Me Anatomy (2022) The Bony Orbit. Accessed on 14.09.22 <https://teachmeanatomy.info/head/organs/eye/bony-orbit/>