Ophthalmic emergencies Flashcards
What is the definition of an ophthalmic emergency?
Condition that affects the eye that requires immediate intervention in order to protect the eye and preserve vision
What are 4 groups that ophthalmic emergencies can be classed into?
- Trauma
- Loss of vision
- Painful red eye
- Double vision
What are 2 of the commonest causes of traumatic eye injury today?
- sports: ice hockey, racket sports
2. DIY, gardening
What proportion of eye injuries occur in the home?
50%
What proportion of eye trauma is blunt trauma?
80%
What proportion of eye trauma is perforating injuries?
19%
What is the definition of blunt eye trauma?
no loss of integrity of the globe, no laceration/cut, but compressive trauma to globe
What is the definition of a perforating eye injury?
Break in integrity of the globe, full thickness cut through cornea or sclera
What is the definition of a intra-ocular foreign body?
Whatever has caused cut in wall of eye is retained in eye, needs to be removed
What are 5 types of eye trauma?
- Blunt
- Ruptured globe
- Intraocular foreign bodies
- Chemical burns
- Non-accidental injury
What is another way of describing a ruptured globe?
Penetrating injuries
What are 8 types of blunt trauma in the eye?
- Lid avulsion
- Periorbital haematoma
- Blow-out fractures
- Hyphaema
- Sphincter rupture
- Iridodialysis
- Retinal detachment
- Choroidal rupture
What is lid avulsion?
Lids torn from insertions
What is a periorbital haematoma?
Bruising around eye, affecting peri-orbital tissues
What are blow-out fractures?
Fracture of orbital floor, roof (rarely) or walls
What is a hyphaema?
Blood within the anterior chamber of the eye (between cornea and iris)
What is a sphincter rupture?
Circular muscle of iris being broken
What is iridodialysis?
tear of iris away from root
What is retinal detachment in eye trauma?
Blunt force sufficient to remove retina from inner surface of globe
What is choroidal rupture?
rupture of major blood vessels in wall of eye
What causes blunt trauma to occur in eye injuries?
When something makes contact with the eye, because it is a closed structure it squashes eye in an anteroposterior direction and stretches the eye and the equator. Mechanical waves are transmitted through the globe
What causes damage to occur in blunt eye trauma?
the mechanical waves are transmitted through the globe and damage can occur to any or all intraocular structures
What can cause you to underestimate the damage in blunt trauma to the eye?
Blunt injury from outside may not look severe but can cause damage to any of these structures in the eye
What should be the first step to take in a lid laceration?
check that the rest of the eye is OK, no concealed penetration injury to the globe
What are 5 types of lid laceration locations that should be referred to the ophthalmologist?
- Crossing lid margins (edge with eyelashes)
- Medial canthus (where upper and lower lid meet at nose)
- Lacrimal apparatus (tear ducts - close to medial canthus)
- Levator complex (muscles that raise upper lid)
- Associated with globe perforations should be referred to the ophthalmologist
Why do lid margins require special attention in lid laceration?
Any disruption to lid margin can cause problems to the ocular surface itself - need to be carefully repaired
How can lid lacerations (other than those that need to be seen by an ophthalmologist) be repaired?
Repair with 6/0 monofilament (same as location anywhere else in body)
What must care be taken for when repairing a lid laceration?
No damage by accidental capture of underlying tissues
What is another thing to consider when repairing lid lacerations?
Tetanus prophylaxis - give booster if unclear
What is the lacrimal punctum of the eye?
Minute openings on the summits of lacrimal papillae on the margin of the eye at the lateral extremity of the lacrimal lake; two lacrimal puncta on the medial (inside) portion of each lid
What is the function of the punctum?
hole where tears drain out of eye to the lacrimal sac then drain into the nose
Why would it be bad if a lid laceration involving the punctum were not repaired by an ophthalmologist?
If laceration were to be simply repaired, the punctum would never communicate with the lacrimal sac, so the patient would end up with watering of eye forever. Ocular plastic surgeon can pass stents through the punctum and reconstruct the tear drainage system as they repair the lid laceration
Why is it important generally for an ophthalmologist/ocular surgeon to repair lid lacerations involving the lid margin/other key parts?
to restore normal anatomy to protect the ocular surface
What is the cause of a peri-orbital haematoma?
Direct blow to orbital region; laxity of tissues around eye mean it can become quite swollen
What is the management of a periorbital haematoma?
- First: check for other ocular damage (e.g. orbital floor fracture, globe perforation, hyphaema, fundal examination), if bony injury suspected –>X-ray.
- Cold compresses for swelling, analgesia
What is a black eye?
a peri-orbital haematoma (large collection of blood within tissue around eye as it is lax)
What are 2 considerations for a patient with a black eye?
cause, other structures that may be damaged
How long will it take for a peri-orbital haematoma to settle?
Number of weeks
What is the cause of blow out fractures?
Direct blow to orbital region
Why do blow-out fractures occur?
because the orbit is a confined space, so blunt force to the anterior aspect means the contents are pushed backward. Bones around the orbit are relatively thin, and as intraorbital contents have nowhere to go they push on the walls and cause fractures. Contents can herniate through the fractures
What are 4 key symptoms of blow-out fractures?
- Orbital pain
- Pain on ocular movements
- Diplopia
- Paraesthesia over maxilla
What are two things that can cause pain on ocular movements after a blowout fracture?
- may involve origin of extraocular muscles, pulling on fractured bone when eyes move
- at time of fracture, bone will open and periorbital tissues will herniate through. As blunt force removed, bony margins close again, pinching periorbital fat/extraocular muscles; as try to move eye, pull against tissue trapped in the fracture
What is the cause of diplopia in blow out fractures?
Capture of orbital tissues and restriction of eye movement
Where will paraesthesia over the maxilla occur in blow out fracture and why?
Cheek on affected side, because often, infra-orbital nerve (from maxillary branch of trigeminal nerve) affected in these fractures. May be bruising or loss of this nerve
What are 5 key signs of a blow out fracture?
- enophthalmus (sunken into socket)
- reduced eye movements
- bony tenderness on palpation around orbital ring
- surgical emphysema
- reduced sensation over V2 (maxillary) distribution
Why is surgical emphysema a common sign of blow out fracture?
fractures tend to fracture into sinuses around the orbit so easy to get air in the tissues
What is the management of blow-out fractures?
Perform X-ray and refer to ophthalmology/ max fax
What is a sign often seen on X-rays in blow-out fracture (look on google)?
‘tear drop’ sign; polypoid mass protruding from floor of orbit into maxillary antrum: is the herniated orbital contents into maxillary sinus, including periorbital fat through fracture in orbital floor
What can be helpful when interpreting x-rays in blow-out fractures, as they can be difficult?
Useful to compare right with left
What 3 key things will be found on examination in blow-out fracture?
- Eye movements limited in affected eye due to tissue trapped in fracture –> mechanical tether
- Pain at extremes of eye movement
- Enophthalmos (look from above/below)
What are the 3 most likely causes of a dilated pupil in the context of trauma?
- traumatic mydriasis (damage to iris muscle)
2. optic nerve problem
What will a head CT show in a blow-out fracture?
soft tissue present in ipsilateral maxillary sinus, protrusion of bony fragments e.g. loss of inferior orbital wall; may be fluid level at bottom of right maxillary sinus (blood)
What can occur mechanically, secondary to hyphaema?
Stretching of iris tissue, tearing of blood vessels, bleeding into this space
What is the cause of a hyphaema?
Direct blow to the eye
What are 3 key symptoms of hyphaema?
- blurred vision
- watering
- photophobia
What causes reduced vision in hyphaema?
likely to have red blood cells in aqueous humour throughout, adherent to corneal endothelium (inner surface of cornea)
What causes watering and photophobia in hyphaema?
blunt force that can cause tearing of iris likely to cause intraocular inflammation
What is the key clinical sign of hyphaema?
blood in the anterior chamber - red level of fluid collecting in lower anterior chamber
What is the management of hyphaema? 5 elements
- look for globe perforation (suggests there’s been significant trauma)
- refer to ophthalmologist immediately; usually admitted
- treatment is bed rest to avoid persistent hyphaema
- topical steroids to settle inflammation and stabilise blood-aqueous barrier to prevent rebleeds
- reduce IOP - blood may block trabecular meshwork in anterior chamber angle, requires intensive management
- secondary bleeds may need surgical evacuation
What is the risk of persistent bleeds in hyphaema, which means surgical evacuation may be needed?
Prolonged risk of raised IOP & can be long term staining of corneal endothelium from blood -> may remain opaque after blood removed and need corneal graft
What can cause an irregular pupil in trauma to the eye?
Sphincter damage (could be a source of bleeding and hyphaema)
What can cause the outline of the pupil not to be perfectly spherical?
can be lumpy due to tears in the circular muscle during blunt trauma, so iris unable to constrict effectively; can also be eccentric shape due to disinsertion of iris from iris root and effectively have 2 pupils (also due to blunt trauma)
What is the treatment for when the iris root has been pulled out of its insertion (iridodialysis)?
surgical repair
What is the common cause of a ruptured globe?
High velocity injury, blunt or sharp. more likely to involve sharp object at high velocity
What are the symptoms of a ruptured globe?
severe pain, loss of vision (sometimes pain may be less)
What are 3 key signs of a ruptured globe?
- subconjunctival haemorrhage
- full thickness scleral and corneal lacerations
- prolapse of intraocular contents
What are 6 aspects of management of a ruptured globe?
- tetanus prophylaxis
- X-ray - assess for intraocular/intraorbital foreign body
- Plastic shield over eye
- urgent ophthalmology referral
- primary repair: restore integrity of globe by stitching holes
- secondary repair: attempt to restore function if associated retinal problem/ damage to other structures
Will all intra-ocular/intra-orbital foreign bodies show up on an X-ray?
no but good place to start
Why is a plastic shield put over the eye in a ruptured globe?
not a pad like after surgery; pressure on globe likely to force contents out of perforation in penetrating injuries, so plastic shield prevents pressure on globe
What is the underlying dark area in a scleral laceration?
choroid (blood vessels)
What can prolapse through a scleral laceration, causing a slit-shaped pupil?
peripheral portion of cornea/cornea-scleral junction, leakage of intra-ocular contents - pupil is pulled off centre
If nothing plugs a scleral laceration/ruptured globe e.g. iris, what will happen to the globe?
complete loss of intra-ocular contents and small shrunken globe when patient presents
What is the treatment for perforation fo soft tissue of the eye through a scleral laceration?
replace iris/ other tissue within eye, incise tissue if has become necrotic, stitch up hole
What can cause the lens to turn cloudy in the case of globe rupture?
corneal perforation; cornea good at self sealing but lens may go cloudy as foreign body passed through cornea and touched lens. Lens clarity maintained by complex ion pump mechanisms (fluid and ion regulation) so will form cataract if mechanisms disrupted and lens clouds
What should you be suspicious of in the case of a sudden cataract?
Penetrating eye injury
What should be the management of a nail gun causing a nail in the eye?
don’t try and pull out; it is touching intra-ocular contents, may be making contact with retina or nerve so important to know where these objects are going before you try and remove them
What is the overall aim in the case of intra-ocular foreign bodies?
aim is to remove it regardless of what has gone into the eye
What are 6 examples of relatively inert substances as foreign bodies in the eye?
gold, platinum, silver, glass, stone, plastic
What are 3 moderately inert substances when foreign bodies in the eye?
lead, zinc, aluminium
What is a moderately toxic substance as a foreign body in the eye?
iron
What are 6 toxic substances as foreign bodies in the eye?
- copper
- thorn
- twig
- wood
- soil
- hair follicle
What is the benefit of knowing what substances are relatively inert when in the eye?
may not cause problems if left in long term whereas more toxic need to come out very quickly
What are the most common forms of foreign bodies in the eye?
- iron (steel grinding/ work related, especially without eye protection)
- twigs, thorns, wood, soil - gardening, chopping bush or tree that swings and hits in face
What generally causes a foreign body to enter the eye?
High velocity object
What are the symptoms of an intra-ocular foreign object? Why can the symptoms be unreliable?
mild to moderate pain, vision may be unaffected; pain is unreliable sign and if goes through sclera unlikely to cause big change in vision
What are the possible clinical signs of an intro-ocular foreign object?
may be minimal, entry site may not be obvious/ can be very small, often self-seals
What are 4 elements of management of an intra-ocular foreign body?
- x-ray
- refer to ophthalmologist
- systemic antibiotics e.g. ciprofloxacin 750mg bd
- vitreo-retinal surgery: depends on where it is, normally need to refer to surgeon
What are 3 possible signs on examination of an intraocular foreign body?
- transillumination may reveal hole in iris (see image)
- dilated pupil and ophthalmoscopy may show foreign body on retina
- patient may have floater blind spot (or no visual changes
Why might it be hard to detect that there is an intraocular foreign body?
cornea has probably self-sealed so no prolapse of contents and not shrivelled eye
What are the 2 types of chemical burns to the eye and their effects?
- Alkalis: rapid penetration (more worrying, rapidly penetrate through intact ocular tissues)
- Acids: aggregate with proteins - more of a burning reaction which prevents deeper penetration
What are 4 symptoms of a chemical burn in the eye?
- Significant pain
- Red
- Photophobia
- Blurred vision
Why will there be photophobia in a chemical burn to the eye?
Due to damage to the cornea and scatter of light, or secondary to intraocular inflammation
Why will there be blurred vision in a chemical burn to the eye?
Affects cornea, removal of corneal epithelium which affects focusing of light on the retina
What are 5 signs of a chemical burn to the eye?
- Epithelial loss: can see with fluoroscein sodium and shining blue light, will see green patch
- Conjunctival injection (hyperaemia) and chemosis (conjunctival swelling)
- Limbal ischaemia (loss of blood supply to border between cornea and sclera)
- Corneal clouding
- Uveitis
Why is limbal ischaemia as a result of chemical burns to the eye worrying?
Limbal stem cells mean the cornea can regenerate its epithelium, so this can cause problems to healing in the cornea
What are 7 aspects of the treatment of chemical burns to the eye?
- Copious irrigation with 0.9% NaCl for at least 30 minutes or until neutral pH (compare pH to other eye; may be 4-5L saline)
- Urgent referral to ophthalmologist
- Admission dependent on extent of burn
- Topical and oral vitamin C (for healing)
- Cycloplegia to dilate, ease pain
- Topical steroids for surface inflammation
- Oral antibiotics
What are 4 examples of alkalis causing chemical burns that patients may present with?
- Oven cleaning fluid - sodium hydroxide (pH 14)
- Drain cleaning fluid - NaOH
- Plaster - calcium hydroxide (worse if dust than if wet)
- Fertilisers (some) - ammonium hydroxide (pH 13)