Ocular trauma Flashcards
what are the 5 categories of ocular trauma?
-physical trauma
-chemical trauma
-radiation trauma
-thermal trauma
-electrical trauma
what are the two types of physical ocular trauma?
closed and open globe
what are the two types of closed globe traumas
-contusion
-lamellar laceration
what are the two types of open globe traumas?
globe rupture and laceration
what are the three types of laceration?
-penetrating
-perforating
-intraocular FBs
what are contusion injuries? give some common causes
common eye traumas that make up 1/3 of cases that are classed as a closed globe injury. Usually caused by accidents like
-sports
-falling
-flying objects
-fighting
give 5 common signs of contusion
*Periocular Haematoma (black
eye /shiner)
* Eyelid swelling
* Ecchymosis (bruise)
* Hyphaemia
* Sub-conjunctival
haemorrhage
what’s the worst and best case scenario of a contusion injury?
-blow out fracture which can cause bone healing problems, bv issues and come with secondary complications
-best case is no blow out fracture so is self limiting and recovery in 1-2 weeks
give 9 secondary complications of blow out fractures due to contusion injury
Commotio Retinae
Conjunctival Chemosis
Vitreous Haemorrhage
RAPD
Macular Hole
Uveitis
Iridodialysis
Corneal Erosion
Lid Laceration
what typically cause lamellar lacerations?
FBs such as sharp objects, flying glass or nails
how can you diagnose lamellar lacerations
with fluorescein, you will see some small scratches that glow, there shouldnt be much staining overall as damage is superficial
what is the first and second most common eye trauma?
1st is corneal abrasions
2nd is corneal foreign bodies
someone with foreign body in the eye, what will they present with?
-redness
-watery eye
-significant pain
how can you search for foreign bodies in the eye?
lid eversion with a lid retractor or bent paper clip to look for small FBs embedded in the superior tarsal conjunctiva
what is a globe rupture?
when very large pressure applied to the eye causes failure of the sclera e.g. falling on a step
On a globe rupture, what scan can and cant you perform? What anaesthetics cant you use?
- cant use MRI or ultrasound but can use CT
-cant use anaesthetics with ketamine
what is a penetrating globe laceration? what can cause is?
-object has gone in with no sign of exit (so something is stuck in the eye)
-Associated with DIY like nails and screws
what is a perforating globe laceration? What do they almost always cause?
where the object has gone in and then out (could just leave a wound or may still be stuck)
-traumatic cataract
what must you not do to a penetrating globe laceration?
remove the FB otherwise you are likely to cause a globe rupture
what is IOP like in a perforating globe laceration and why? what can this lead to?
Iop typically is very low which means the optic nerve head is under strain as well as the macula as there’s no vitreous pressure to make sure its pushed to the retina making retinal detachment very likely
low iop can also cause the globe to shrink
what is seidles test for and how do you do it?
-to determine if the object that has caused a globe laceration has entered the aqueous
-You instill a large amount of fluorescein and then if aqueous has been damaged, then the fluorescein will leak out and the rate of leakage determine how deep/ large the wound is
what are intraocular bodies?
they are a type of penetrating injury where prognosis depends on the material of the FB
what materials and reactions can lead to intraocular FBs?
-iron = siderosis bulbi
-copper = chalcosis bulbi
-vegetative = fungal keratitis / endophthalmitis
-high velocity = complete ocular penetration
-human bites = fulminant infection
what ocular problems can an intraocular FB of iron cause? what about copper?
Iron:
-CAT
-OAG
-RD
-iris atrophy
copper:
-maculopathy
-retinal toxicity
-vitreous changes
what are the three types of chemicals that can cause chemical traumas?
-surfactants
-acids
-alkali
(combinations are also possible)
give examples of surfactants that can cause ocular traumas
-paint thinner
-degreaser
-ethanol
-petrol
when may prognosis be compromised in surfactant caused ocular trauma?
if the limbal stem cells are destroyed due to no cells to regenerate and replace damaged cells
what are symptoms of surfactant caused ocular trauma?
-redness
-pain that is intense
give examples of acids that may cause ocular trauma?
-sulphuric acid (car batteries)
-vinegar
-lemon
-phosphoric acid (cleaning products)
-HCL (vomit and concrete etchers)
what acid can cause the most dangerous ocular trauma where can it be found and why is it the most dangerous?
hydrofluoric acid found in refrigerants and released when certain plastics are burnt
As the fluoride ions replace the calcium ions in the body causing:
-apoptosis of otherwise healthy cells
-apoptosis of adjacent healthy cells as they cant carry out respiration
give examples of alkalis that can cause ocular trauma
-ammonia (toilet cleaners)
-Sodium hypochlorite /hydroxide (bleach /drain unblocker)
-calcium hydroxide (cement)
what are the signs of someone who has had alkali caused ocular trauma?
-white cornea giving fish like appearance
-red sclera due to death of conjunctival vessels
which type of chemical trauma is the worst and why?
alkali because unlike acids, they penetrate the eye more deeply. Acids tend to cause immediate pain and damage by coagulating proteins, forming a solid precipitate that limits further penetration and damage. In contrast, alkalis saponify fats in cell membranes, making cells more soluble. This allows alkalis to penetrate deeper into the eye, continuing to cause damage as they spread through ocular tissues, potentially reaching the retina and causing more extensive injury.
give an example of an irritant that can cause chemical ocular trauma. what exactly does it do
Chloroacetophenone (tear gas
-Causes epithelial defects, stromal haze, oedema which leads to mild to moderate injury what depends on concentration/duration of exposure
How do you treat a patient who has suffered a chemical trauma?
- make sure to rinse immediately (ideally with sterile saline but water is fine in an emergency) from the nasal side outwards so you’re not rinsing the chemical into the lacrimal caruncle
- use universal indicator strip to determine the pH of the tears
- do not stop irrigating until the pH returns to neutral or after 20 mins
how else can you treat a patient with chemcial ocular trauma thats not rinsing with water?
by using a buffer such as sodium bicarbonate solution to neutralise the pH
what is the most common types of radiation trauuma?
non-ionising radiation trauma such as from microwaves, UV or infrared light
what can typically cause uv radiation trauma?
things that source radiation:
-welding
-tanning beds
things that reflect radiation:
-skiing
-sailing
how does uv radiation present?
delayed presentation post exposure:
-intense pain
-redness
-peeling conjunctiva (as it heals)
-pain is usually worse than how it actually looks
what do the most severe UV radiation trauma symptoms cause
arc eye
name 9 conditions associated with UV over exposure
- Photokeratitis
- Cortical cataract
- Pterygium
- Pinguecula
- Band keratopathy
- Heat shock ( UV reactivates)
- AMD ( UV Implicated)
- Droplet keratopathy ( UV Implicated)
- Conj/ corneal squamous cell carcinoma
give 4 examples that can cause visible light trauma, what does it cause?
-lasers
-direct sunshine
-arc lights
-solar eclipse (can cause solar maculopathy)
permanent blindness in the effected area
what are the two main types of thermal trauma and give examples
-Infared radiation e.g. glass blowing, blacksmith, chef
-conduction (usually linked to FBs) e.g. boiling liquids, fireworks and sparks
what can you use to manage thermal trauma?
-cataract extraction
-prophylactic antibiotics
-painkillers
-cold compress
-in case of conductive treatment as FB/ chemical as appropriate
when can someone suffer electrical trauma?
if they work with high voltage electricity or struck by lightening
what can electrical ocular trauma lead to?
-irreversible damage to the optic nerve
-damage to the cornea which usually resolves
-damage to the lens which causes a traumatic cataract
-can cause macular holes
give an example of an injury that can involve a combination of ocular traumas
insect stings or bites as they involve:
-Puncture (from the sting/mandibles)
-Infection (from their dirty feet/mouths)
-Injection (of saliva/venom/digestive enzymes/acids)
-Massive histamine response (from the patient)
-Foreign Body (from the stinger)
could be managed by very strong steroids to reduce the inflammation
fireworks
-chemical and thermal injuries
give an example of how fake eyelashes can cause a trauma
using too much glue to stick them on causing large amounts of heat to be released hence creating thermal burn to the eyelids
give an example of how CL could escelate a physical trauma
airbag in a car crash caused the driver’s hard scleral contact lenses to shatter bursting the eye and allowing the uvea to escape causing globe rupture and possible also
- commotio retinae
- retinal detachment