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
What are the symptoms of episcleritis?
Mild pain
Note that sight is NOT affected
What is the treatment for episcleritis?
NSAIDS drops (tablets may help too
or
steroidal eye drops if more severe (query scleritis)
How can scleritis and episcleritis be differentiated?
Pain in scleritis is severe!
What is Phlyctenular conjunctivitis?
localized noninfectious inflammatory/ hypersensitivity disorder
of the conjunctiva
With associated subepithelial nodules of the conjunctiva.
NOTE that “phlyctena” is the Greek word for “blister”
Explain the signs and symptoms of uveitic red eye (aka ciliary/circumcorneal congestion).
Dusky redness predominantly around the cornea.
How can ciliary/circumcorneal congestion (uveitis) be differentiated from conjunctival congestion (conjunctivitis).
ciliary/circumcorneal congestion (uveitis) will NOT blanch with vasoconstrictors, conjunctival congestion (conjunctivitis) will.
Explain the signs and symptoms of conjunctival red eye (aka conjunctival congestion).
Bright redness predominantly in the conjunctival fornices (the extreme superior and inferior folds)
What are the main causes of conjunctivits?
Viral
Bacterial
Allergic
What are the signs of viral conjunctivitis?
gritty eyes
watery discharge
follicles (non-specific inflammation)
enlarged lymph nodes
More commonly bilateral
What is the difference between follicles and papillae of the eye?
Follicles are due to collections of lymphocytes and are raised pink lesions due to viral conjunctivitis
Papillae are collections of proliferating vessels covered by thickened epithelium. They are flat, white lesions due to allergic conjunctivits
What are the signs of bacterial conjunctivitis?
gritty eyes
purulent discharge
enlarged lymph nodes
More commonly unilateral
What are the signs of allergic conjunctivitis?
itchy eyes
watery-stringy (these are mucous strands) discharge
papillae (non-specific inflammation)
no enlarged lymph nodes
More commonly bilateral
What is the commenest cause of neonatal conjunctivits worldwide and in the western world?
Gonococcal worldwide. It is VERY serious.
Chlamydia in the western world
What is a common cause of viral conjunctivitis is adults?
adenovirus
How does herpes simplex effect the eye?
It causes a branching dendritic ulcer on the cornea i.e. keratitis.
How is HSV keratitis treated and managed and why.
It is treated with acyclovir ointment.
It required management with steroids AND acyclovir as the body will keep mounting an immune response to the antigens which have been left behind. Acyclovir is used as if it is not the virus will come back down form the trigeminal nerve where it lays dormant and reinfects.
What is a hypopyon?
A level of sterile pus (protein and cells) exuded from the iris
It is due to toxins released from a bacterial ulcer on the cornea passing though the cornea.
This builds in the anterior chamber and is visible to the naked eye.
How can uveitic red eye and conjunctival red eye be told apart?
uveitic red eye - will NOT blanch with vasoconstrictor
conjunctival red eye - WILL blanch with vasoconstrictor
If there are folds of conjunctiva:
uveitic red eye - the blood vessels will NOT move with these.
conjunctival red eye - the blood vessels WILL move with these.
Where does the red colour in uveitic red eye actually come from?
The redness comes from the deeper vessels of the uvea mainly the anterior ciliary vessels.
Where does the red colour in conjunctival red eye actually come from?
The redness comes from the superficial vessels of the conjunctiva.
How does the blood flow in uveitic red eye and conjunctival red eye differ?
Under magnification:
uveitic red eye - centrifugal blood flow (from cornea outwards) can be seen
conjunctival red eye - centripetal blood flow (from periphery in towards cornea) can be seen
Which type of conjunctivitis is associated with crusting and matting of the eye lashes?
Bacterial conjunctivitis
Which of the types of conjunctivitis require treatment?
Bacterial conjunctivitis
