Ocular trauma Flashcards
Cornea definition
transparent layer forms the anterior border of anterior chamber
Which structure divides globe into anterior and posterior chambers
lens
Anterior chamber boundaries
Between cornea and iris
What liquid fills the anterior chamber
Aqueous humor: solution of sodium chloride and other ions
What liquid fills the posterior chamber
Vitreous humor: clear jelly-like substance
Canthal tendon
Eyelids have tendinous attachments (canthal tendons) medially and temporally on the bony orbit which keep the globe from moving forward
The intraocular pressure measurement device
Hand held tonometer
Intraocular pressure range
between 8 and 21 mmHg
Assessment of intraocular pressure in absence of tonometer
Press on the eyes with index finger and eye lids closed
if firmer, may indicate increased pressure
Cornea or conjunctiva laceration implication
When full-thickness indicate an open globe
Management of full-thickness lid laceration
Repair within 72 hrs by a surgeon familiar with eyelid and lacrimal drainage anatomy
Abrasion of the cornea and conjunctiva treatment
ophthalmic ointemnt
Problem with hyphema
blood in the anterior chamber
Retrobulbar haemorrhage with compartment syndrome sx
Decreased vision
Elevated eye pressure
Asymmetrical proptosis
Tight eyelids against the globe
How long after impairment of blood supply to the eye as a result of compartment syndrome does loss of vision occur
1.5 hrs
Mx of retrobulbar haemorrhage causing compartment syndrome
Canthotomy (cutting the dermis) and cantholysis (equivalent to doing fasciotomy)
Mx of chemical burns to eyes
1 Lt of saline irrigation through morgan lens
Stop every 30 mins, for 5 to 10 mins, then check the tear pH (aim 7.0)
Def of open globe
eye injuries that have full-thickness penetration through the sclera or cornea
Seidel test
Looks for small leaks of aqueous fluid
Anaesthetise the eye
Wet the fluorescein strip
Wipe over the area of concern
If leak present, dark orange changes to light orange or green
Preparation for transfer to eye unit in pt with open globes
Rigid eye shield with no padding
IV abx: eg gatifloxacin or levofloxacin
Minimise eye movements
