Management of ocular trauma

Question 1

what is a corneal abrasion

list 3 causes that it may be due to

Answer 1

Corneal abrasions are superficial defects in the epithelium of the cornea

May be due to:
- Trauma (fingernail, twig, edge of paper, mascara brush)

• Sub-tarsal foreign body (abrasion gets adherent to upper sub-tarsal plate and abrades cornea as px blinks)
• Contact lens trauma (may be trying to remove a lens thats not actually there or aggressive during insertion and removal or from the lens itself)

Question 2

name a direct and a secondary cause of a corneal abrasion

Answer 2

Direct: trauma

Secondary: Sub-tarsal foreign body

Question 3

which type of corneal abrasion are common

what do they account for, by how much and why

Answer 3

Traumatic abrasions are common

Accounting for approx. 40% of acute ophthalmic presentations to A and E departments

Because of the acute pain associated either by the abrasion or the foreign body

Question 4

list 3 predisposing factors of a corneal abrasion

Answer 4

Corneal dystrophy - such as an epithelial basement membrane dystrophy (Cogans)

Diabetes - has more fragile epithelium so breaks down more easily

Neurotrophic keratitis - secondary to hepatic infection caused by herpes simplex virus

Question 5

explain why/how people with the corneal dystrophy cogans syndrome is a predisposing factor to a corneal abrasion

Answer 5

because normally the cornea is bound down to the stroma by hemidesmosomes and anchoring filaments which holds the epithelium down to the surface of the eye

however is cogans syndrome, this is compromised and there is no good attachments of the epithelium to the underlying stroma = these people are predisposed to corneal abrasions

Question 6

explain why/how neurotrophic keratitis is a presiposin factor to a corneal abrasion

Answer 6

neurotrophic keratitis is secondary to a hepatic infection by the herpes simplex virus and these people have had a viral keratitis
people with a viral keratitis are found to have a very unhealthy epithelium down to a loss of neural function

the viral keratitis tends to affect the nerve supply to the cornea, the corneal nerves have a alerting mechanism and also has a trophic function (i.e. the epithelium needs a nerve supply in order to maintain it’s integrity)

therefore if we take the nerve sensation away (as with neurotrophic keratitis) = the cornea becomes more vulnerable and the epithelial cells will more readily break down.

Question 7

list the 4 symptoms of a corneal abrasion

Answer 7

Pain - from any disruption to the surface

Photophobia - just a disturbance from bright light (so not same as uveitis)

Blepharospasm - eyelids forced shut and cannot open from pain

Lacrimation

Question 8

what is a clinical feature defined as

Answer 8

both signs and symptoms

Question 9

what are the 7 signs of a corneal abrasion

Answer 9

Lid oedema

Conjunctival hyperaemia (which is mostly associated with pain)

Corneal epithelial defect

Corneal oedema (barrier is removed and water can enter into the cornea from the tear film)

Visual loss (if central abrasion)

May be secondary AC inflammation (when the blood aqueous barrier breaks down)

Question 10

how can you clinically assess a secondary AC inflammation in someone who has had a corneal abrasion

Answer 10

to look for inflammatory cells and flare from the breakdown of the blood aqueous barrier = protein will be present which gives rise to scatter, called flare

if it is associated with major damage, it will cause a anterior chamber activity

when shining a light from the slit lamp onto the epithelium you will see lots of light scatter and also a lot of light coming back at you from the lens (in the anterior chamber)

Question 11

list the 5 steps of your clinical assessment of someone who has had a corneal abrasion

Answer 11

Determine cause of injury - from your history to determine how bad the cause is

Measure VA - ALWAYS

Evaluate abrasion with fluorescein

• Size
• Depth - optic section
• Confirm no FB present (evert lid)

Check for AC inflammation - turn off lights completely, as want no background light and use the smallest and brightest beam to detect

Topical anesthesia to aid examination - to help with lid eversion etc

Question 12

what is the 3 aims of management of a corneal abrasion

Answer 12

Pain control - advise px to buy oral analgesics e.g. ibuprofen

Facilitate healing - at rate which we expect by booking follow up check to see cornea is healing

Infection control - as taken away barrier so prophylactic anti biotic

Question 13

what 2 things is the choice of topical antibiotic treatment for a corneal abrasion dependent upon

and how will you give the topical antibiotics to this patient if they have either of these

Answer 13

• size and depth of the abrasion
• contamination from organic matter e.g. gardening injuries or debris in the abrasion

you will give the full course of the antibiotic which is either 4x drops per day with ointment at night and continue that for a whole week

if you don’t do it this way then theres no point of doing it at all as theres no benefit of putting chloramphenicol just once at that time

Question 14

list 8 points about the management and risk of a corneal abrasion

Answer 14

Chloramphenicol 0.5% eyedrops or 1% ointment

For large abrasions 1% cyclopentolate to prevent ciliary spasm (as ciliary spasm is caused by the pain, so it is thought that cyclopentolate will reduce the pain)

Analgesia (topical NASID and/or paracetamol/ibuprofen

No patching as does not improve wound healing

Arrange follow up to monitor healing

Refer if deep abrasion or contaminated with foreign material

Advise on eye protection

Risk of recurrent epithelial erosion syndrome - as when healing, it is still vulnerable to break down recurrently

Question 15

why is patching not advised as a management option for corneal abrasion and what is better to use instead

Answer 15

because eye padding potentially made the corneal abrasion worse as when the eye is hidden behind the pad = can’t see any changes to that eye, so if it develops any complications following the abrasion, then we would not have known

a thin soft bandage plano CL is a better option to protect the cornea and bridge the pain whilst being able to see any changes occurring to the cornea

Question 16

give examples of what can cause a sub-tarsal foreign body

Answer 16

FB entering the eye such as:
wind blown
particle falling into the eye (e.g. DIY)

most of the time the tears will wash the FB away, but embedded debris thats stuck on the tarsal plate has to be removed by the clinician

Question 17

what are the clinical features i.e. 2 signs and 3 symptoms of a sub-tarsal foreign body

Answer 17

Symptoms

• Foreign body sensation (whereby every time the px blinks, will traumatise the ocular surface)
• Lacrimation

Signs

• Hyperaemia
• Embedded FB
• Corneal FB tracks - established by using flourescein

Question 18

what will be the 4 management steps for a sub-tarsal foreign body

Answer 18

Topical anaesthesia to aid examination

Remove FB by saline irrigation or saline wetted cotton bud - which is easier to do under slit lamp

Consider prophylactic antibiotic if corneal damage

Advise on suitable eye protection

Question 19

list 3 possible causes of a corneal foreign body

Answer 19

Patient may give a history of foreign body entering the eye

• wind blown
• DIY or gardening
• high velocity (hammering or grinding)

Question 20

what are the clinical features i.e. 3 signs and 3 symptoms of a corneal foreign body

Answer 20

Symptoms

• Foreign body sensation
• Lacrimation
• Blurred vision - depending on location

Signs

• Embedded FB
• Linear scratches
• Rust ring from ferrous material = contains iron (must be very careful of this as its very toxic to the epithelium)

Question 21

list the 5 steps carried out in the clinical assessment of a corneal foreign body

Answer 21

Determine cause of injury - by taking a good history

Measure VA

Rule out multiple particles - do a full assessment

Assess depth of corneal foreign body (slit lamp optical section) - slit lamp optic section

Topical anaesthetic may aid examination

Question 22

what will be your management of a corneal foreign body and what are the 6 steps of doing this

Answer 22

removal of the foreign body

• Loose FB can be irrigated with saline - try this first
• Conjunctival FB removed with cotton bud
• Assess depth of corneal FB with slit lamp
• Embedded corneal FB should be removed with a hypodermic needle
• Check VA before and after removal
• Evaluate need for antibiotic prophylaxis

Question 23

what should be used to remove a corneal foreign body

Answer 23

a hypodermic needle

Question 24

describe how a hypodermic needle us used to remove a corneal foreign body

Answer 24

Hold the needle with the bevel uppermost and horizontally ‘flat on’ to the cornea
i.e. bevel should face the optom

Gently lift off the foreign body (FB) from the corneal surface - by doing a rocking motion to scoop the FB off the cornea and flip it out

Question 25

list 5 points about the further management of a corneal foreign body after it has been removed by the hypodermic needle

Answer 25

Do not patch the eye

Prophylactic antibiotic if risk of infection

Analgesia - for the pain

If penetrate into stroma or presence of rust ring then refer to an ophthalmologist

Advise on suitable eye protection

Question 26

when should you refer a patient with a corneal foreign body to the ophthalmologist (instead of managing yourself)

Answer 26

if it penetrates into the stroma or in the presence of a rust ring

Question 27

what 3 things will you think to do if you see a 24 year old student who suffers an injury to his right eye whilst playing squash and what is your diagnosis

Answer 27

History questions
Assessment
Management

Blunt trauma

Question 28

list 3 possible causes of a blunt trauma

Answer 28

RTA
sport
assault

Question 29

list the 4 clinical signs of a mild case of blunt trauma

and

list the 6 clinical signs of a severe case of blunt trauma

Answer 29

Mild cases:

• eyelid swelling
• bruising
• sub-conjunctival haemorrhage
• corneal abrasion

Severe cases:

• blow out fracture
• hyphema
• raised IOP
• iridodialysis - iris becoming detached in the periphery at its root
• commotio retinae
• retinal detachment

Question 30

list the 7 steps carried out in your clinical assessment of a blunt trauma

Answer 30

History (detailed)
VA
Ocular motility - to check for blow out fractures and diplopia particularly on up gaze
IOP
Pupils - look for RAPD
Anterior eye exam
Posterior eye exam

Question 31

list the 7 signs of a trauma which will cause rd flags and will need referral

Answer 31

Reduced VA
Diplopia
Enophthalmos
Raised IOP
Hyphaema
Anisocoria/distorted pupil - associated with iris trauma 
Ruptured/perforated globe - uvea breaking through sclera 
Vitreous haemorrhage

Question 32

what change in raised IOP will be a red flag and hence an action to refer the px as a result of trauma

Answer 32

it will be unilateral
so use the other eye as a control
if there is more than 5mmHg difference between the 2 eyes

then it is likely to be a consequence of trauma

Question 33

list 4 types of ocular trauma from least to most serious

Answer 33

corneal abrasion

sub-tarsal foreign body

corneal foreign body

blunt trauma