Acute red eye Flashcards
What are the two main causes of red eye?
Haemorrhage:
Congestion which can be:
a) Localised
b) Generalised - conjunctival or ciliary
What are the two types of haemorrhage that can cause red eye?
Subconjunctival (between conjunctiva and sclera)
Retrobulbar
What is the most common type of haemorrhage that gives red eye?
Subconjunctival
Describe the pathophysiology of a reterobulbar haemorrhage?
Bleeding behind the eye ball which tracks forward to lie under the conjunctiva
How do the signs of subconjunctival haemorrhages differ with retrobulbar haemorrhages?
Subconjunctival haemorrhages –> the posterior edge of the blood patch is visible.
Retrobulbar haemorrhages –> and the posterior edge is not visible.
What are the signs of reterobulbar haemorrhage?
No visible posterior edge + red vessels are not visible
Raised pressure (thus a protruding eye ball)
Restricted eye movements
(Ptosis, dilated pupil)
What are the adverse outcomes of reterobulbar haemorrhage?
It is an EMERGENCY –>
optic nerve compression
blindness
What are the potential causes of subconjunctival haemorrhage?
Occur after surgery
during increased pressure from coughing
Bleeding disorders or meds (aspirin or warfarin)
Trauma
What are the signs of conjunctival haemorrhage?
Usually asymptomatic
Sharp pain can be felt at initial haemorrhage
Redness at sight of haemorrhage
What are the main causes of reterobulbar haemorrhage causing red eye?
The main cause is iatrogenic (injection of anaesthetic)
The second main cause is trauma (head injury or optic floor fracture)
What causes the redness in cogestion red eye?
Vascular engorgement
What are the causes of localised congestion red eye?
episcleritis
and
phlyctenular conjunctivitis
What are the causes of generalised congestion red eye?
conjunctivitis
keratitis (inflammation of cornea)
uveitis (inflammation of iris, ciliary body and choroid)
acute glaucoma
What is the episclera?
It is the outermost layer of the sclera and is in contact with the conjunctiva. It is NOT scleritis.
What are the potential underlying causes of episcleritis?
collagen vascular disease
and
rheumatoid arthritis