wk9: AED - Conjunctival Infections 1 [DG] Flashcards
Describe a non-infective reason why eyelids might be stuck together in the morning
Excess tearing from allergies can result in a crusty byproduct which will stick the lids together
How does a non-infectious cause of eyelids sticking together in the morning differ from an infectious cause? (in terms of the reason they are sticking together) (1.5)
non-infectious: crusty byproduct sticking lids together
infectious: gooey byproduct sticking lids together
What are the general symptoms of conjunctivitis? (5)
Discomfort
Discharge
Increased redness
Variable vision loss due to discharge, tear film disruption
Mild photophobia due to PEE/SPK (bit questionable)
How can discomfort vary with conjunctivitis aetiology? (3)
Gritty/scratchy = bacterial, viral (dry eye) Itchy = allergic Burning = bacterial, viral (dry eye)
How can discharge vary with conjunctivitis? (3)
watery
mucoid
mucopurulent
What is a good question to ask when a patient presents with variable vision? (1)
Does blinking clear up your vision? (i.e. b/c when you blink you create a new tear film layer, so this can help you see if tear film disruption is a problem, in which blinking should make it clearer for a bit)
Does the “green-ness” of the discharge in conjunctivitis patients matter?
Not really
What are general signs of conjunctivitis? (6)
Conjunctival reaction Little or no corneal involvement Slight lid oedema Lymphadenopathy Pseudomembranes/membranes Discharge
(note patient won’t necessarily have all of these)
What sorts of conjunctival reaction might you get in a patient with conjunctivitis? (3)
Injection/hyperaemia (redness)
Chemosis (oedema/swelling)
Follicular/papillary? (i.e. need to identify which one it is)
How do you use conjunctivitis features to make a differential diagnosis? (5)
Type of discharge Type of conjunctival reaction (papillary or follicular) Pattern of hyperaemia Presence of pseudomembranes/membranes Presence/Absence of lymphadenopathy
What is the downside to patients physically pulling out mucoid ropey-like substance from their eye? (1)
This stimulates the eye to produce more mucoid. Problem not resolved
Instead of pulling out mucoid physically, how is mucoid best removed from the eye? (1)
Wash it out with saline. This means you won’t produce any more mucoid
What does the discharge from conjunctivitis consist of? (6)
Exudate from dilated conjunctival blood vessels Mucus from goblet cells Debris from dying or dead cells Tear overproduction WBCs (usually neutrophils) Microorganisms
What are the diagnostic rules of thumb for conjunctivitis discharge? (4)
Watery = viral/allergic
Mucoid (ropy) = allergic
Purulent = acute bacterial
Mucopurulent (ropy purulent) = mild/chronic bacterial or chlamydial
List the general aetiologies of conjunctivitis (7)
Viral Bacterial Allergic Toxic CL related Trauma Assoc. with lid and/or corneal pathology
How does inflammation of the eye affect goblet cells? (1)
causes them to overproduce
Name a condition where you can get follicles superiorly? (1)
Chlamydia
Is it normal to have a few follicles in the palpebral conjunctiva?
yep
When do follicles in the palpebral conjunctiva become apparent?
at 2 years old and older
Where are follicles most common? (1)
Forniceal conjunctiva
What do follicles near the lid margin or centre of tarsus suggest? (1)
suggests pathology
How do follicles look in terms of blood vessels? (1)
Blood vessels at base or surrounding
What causes follicles? Describe the mechanism (1)
Hyperplasia of lymphoid tissue in conjunctival stroma
How can the size of follicles in a follicular conjunctival reaction vary?
0.2-2mm depending on severity and duration of inflammation
Name the 3 main acute causes of follicular conjunctival reactions
viral infections
chlamydial infections
medication hypersensitivity
Which is more variable in appearance, follicular or papillary conjunctival reactions?
papillary
How would you describe a papillary reaction in the conjunctiva?
subepithelial fibrovascular core with surrounding oedema and cell infiltration
Where can a papillary conjunctival reaction occur? (2)
Palpebral conjunctiva
Bulbar conjunctiva at the limbus
What is a hallmark characteristic feature of papillae? (that can be used to distinguish them from follicles) (1)
characteristic central blood vessel (sometimes difficult to see in large papillae)
Describe the general appearance of a papillary reaction
Fine mosaic pattern of elevated polygonal hyperaemic areas often described as being like cobblestones
Can individual papillae vary in size? How?
Yes. Individual papillae can increase in size with more intense reactions
Name 4 common causes of a papillary conjunctival reaction
chronic blepharitis
allergic disease
bacteria-related infection
contact lens related problems
How can you further classify conjunctivitis with follicles present? (2) [usefull table]
With swelling of pre-auricular lymph node
Without swelling of pre-auricular lymph node
Where are the pre-auricular lymph nodes?
located just in front of your ears
Where are the submandibular nodes?
Located under mandible, basically they are on the upper part of your neck close to centre. You can feel them pretty easily
How can you further classify conjunctivitis with follicles present and swollen pre-auricular nodes? (2) [useful table]
Herpetic signs present (e.g. dendrites, skin vesicles)
Herpetic signs not present
Assume you have a patient with conjunctivitis with follicles, pre-auricular node swelling and herpes signs present. What is the likely aetiology diagnosis? [useful table]
HSV
Assume you have a patient with conjunctivitis with follicles, pre-auricular node swelling and no signs of herpes. What is the aetiological diagnosis? (2) [useful table]
Adenoviral or Chlamydia
What is the diagnosis for a patient with conjunctivitis with follicles and no pre-auricular node swelling? (3) [useful table]
toxic conjunctivitis
molluscum
pediculosis
How can you classify papillary conjunctivitis? (3) [useful table]
Classify based on type and amount of discharge:
Severe purulent
Scant purulent
Watery or Mucoid
What is the likely diagnosis for a papillary conjunctivitis with severe purulent discharge? (1) [useful table]
GPC
What is the likely diagnosis for a papillary conjunctivitis with scant purulent discharge? (1) [useful table]
Bacterial other than GC
What is the likely diagnosis for a papillary conjunctivitis with watery or mucoid discharge? (2) [useful table]
Allergic
Atopic
How common are membranes/pseudomembranes?
Relatively rare, may see one in clinic every 8 weeks or maybe only a few times a year
What is a pseudomembrane?
coagulated fibrinous exudate lightly adherent to inflamed conjunctiva
What happens to the conjunctival epithelium when you peel the pseudomembrane off?
Remains intact. (Pseudomembrane can be peeled without bleeding)
Name the 3 main causes of pseudomembranes
adenoviral infection
gonococcal conjunctivitis
alkali burns
Which is worse, acid burns or alkali burns. Why?
Alkali burns are worse, because while an acid burn is an “event”, an alkali burn “keeps going for an extended time”, so it lasts longe
What is a true membrane?
coagulated fibrous exudate anchored to the inflamed conjunctival epithelium (rare)
How does peeling of a true membrane compare to peeling of a pseudomembrane?
peeling of a true membrane is more difficult and rips the conjunctival epithelium, causing bleeding from conjunctival vessels
Name 4 common causes of true membrane formation
Beta-haemolytic streptococci
Diphtheria (corynebacterium)
Gonococcal
Autoimmune conjunctivitis
Why do membranes and pseudomembranes have to be removed?
To stop scarring of underlying tissue
Are true membranes and pseudomembranes safe to remove?
Both are safe to remove
What MUST we do to confirm if somebody has adenovirus? (1)
Lymphadenopathy
What does lymphadenopathy involve?
Feeling the different lymph nodes to check for swelling/see if they are raised
What lymph nodes are we particularly interested in during lymphadenopathy? (2)
pre-auricular nodes
submandibular nodes
What 3 infections is lymphadenopathy commonly performed for?
Viral infection (adenovirus)
Chlamydial infection
Severe gonococcal infections
When performing lymphadenopathy as an optometrist, should you keep the patient’s shirt on? ;)
Yes you should
Why is gonococcus dangerous?
Because it can get through intact cornea
In regards to non-gonococcal bacterial conjunctivitis, describe the following:
A: How common?
B: Acute or chronic?
C: Do they persist or are they self-limiting?
A: very common
B: acute
C: usually self-limiting within 10-14 days
In regards to non-gonococcal bacterial conjunctivitis:
D: Unilateral or bilateral?
E: Symmetrical or Asymmetrical?
D: Bilateral
E: Asymmetrical - with onset over a couple of days (usually starts in one eye then transfers)
Name 4 common pathogens that can cause non-gonococcal bacterial conjunctivitis
Staph aureus
Staph epidermidis
Strep pneumoniae
Haemophillus influenzae (kids)
List the symptoms of non-gonococcal bacterial conjunctivitis (5)
Acute onset of: redness, gritty/burning, sticky discharge
Eyelids frequently stuck together on waking
May have mild photophobia due to SPK
Why would someone with bacterial conjunctivitis acquire SPK? (1)
Due to the endotoxins released from the bacterium damaging/breaking down the epithelium
Can Darryl Guest think of a bacterial infection that ISN’T an acute onset?
No he can’t. So all bacterial infection = acute onset.
What 3 factors make the perfect environment for bacteria? (3)
Moist
Dim
Anaerobic
What is the most common cause of conjunctivitis presentation in eye clinics?
Viruses. By far
What are the signs of bacterial conjunctivitis? (5.5)
Conjunctival hyperaemia, especially in fornices
Mild SPK
Mild papillary reaction
Mucopurulent discharge
Crusting on lids, phlyctenules, corneal marginal infiltrates
What are phlyctenules?
A small vesicle or postule especially: one on the conjunctiva or cornea of the eye
What ddx exist for bacterial conjunctivitis? (3)
Viral conjunctivitis
Allergic conjunctivitis
Gonococcal conjunctivitis
