wk7: AED - Complex Conjunctivitis and Lids and Blepharitis Flashcards
Is ophthalmia neonatorum usually unilateral or bilateral?
bilateral
List the causes of ophthalmia neonatorum (5)
Chlamydia Gonococci Herpes Simplex Simple bacterial conjunctivitis Chemical
Which cause of ophthalmia neonatorum is the most common in the U.S?
Chlamydia
Of the causes of ophthalmia neonatorum, which ones are via exposure during delivery? (3)
Chlamydia
Gonococci
Herpes Simplex
Which pathogens/substances cause ophthalmia neonatorum due to exposure after delivery? (2)
Simple bacterial conjunctivitis (usually post-delivery)
Chemical
At what times do the different types (based on causes) of ophthalmia neonatorum manifest? (5)
Gonococcal: manifests 24-48 hours after delivery
Herpes Simplex: manifests around 1 week after delivery
Chlamydial: manifests around 2nd week after delivery
Simple bacterial - not stated, probably varies. Chemical -probably depends, but you’d expect quick onset. Silver nitrate drops for instance have onset 2 hours
How long does ophthalmia neonatorum from silver nitrate drops last?
About 24 hours
Why would you administer silver nitrate drops to babies? (1)
prophylaxis for gonococcal infection
What dfferential diagnosis exist for ophthalmia neonatorum? (1) How does this differ?
Nasolacrimal duct obstruction - has a bit of gooey eye you can wash out with no sign of redness
How do you treat chemically caused ophthalmia neonatorum?
irrigate with sterile saline and frequent non-preserved artificial tears
How do you treat non-chemically caused ophthalmia neonatorum? (1.5)
Immediate referral for isolation of pathogen and tx with appropriate antibiotic/antiviral
What are the 2 types of adult chlamydial conjunctivitis?
Adult inclusion conjunctivitis
Trachoma
What 3 species are responsible for chlamydial conjunctivititis in adults?
C. trachomatis
C. psittaci
C. pneumoniae
Is C. trachomatis in humans more or other animals?
almost exclusively human
What serotypes of C. trachomatis are involved in trachoma? (4)
A, B, Ba, C
What serotypes of C. trachomatis are involved in inclusion conjunctivitis or paratrachoma? (1)
Serotypes D-K
What do C. trachomatis serotypes L1, L2 and L3 do? (1.5)
are agents that infect tissues deeper to the epithelium and cause lymphogranuloma venereum
When does ophthalmia neonatorum present?
Within first 4 weeks of life
How is adult inclusion conjunctivitis most commonly transmitted? (1)
sexually
What are the symptoms of adult inclusion conjunctivitis? (6)
mucopurulent discharge (or watery)
gritty FB sensation
sometimes blurred vision (uni or bilateral)
often chronic, may seem acute
often assoc. with urethritis, vaginitis, cervicitis
high percentage of chlamydial STDs asymptomatic
List the signs of adult inclusion conjunctivitis (5)
Usually unilateral
Follicles (particularly upper tarsal conjunctiva, limbal follicles also possible)
Conjunctival chemosis
Preauricular or submandibular lymphadenopathy common
Marginal subepithelial corneal infiltrate + superior pannus in chronic prolonged cases
Define pannus
an abnormal layer of fibrovascular tissue or granulation tissue. e.g. a corneal pannus means the growth of fine blood vessels onto the clear corneal surface
How hard is adult inclusion conjunctivitis to treat?
Very easy to treat, just one tablet. GP will prescribe - 1 azithromycin will take care of it. However, the chlamydial version will have to be tracked by the health department as it’s a transmissable disease so a swab will need to be taken.
What ddx exist for adult inclusion conjunctivitis? (3)
adenoviral keratoconjunctivitis
herpes simplex keratitis
trachoma
List treatment strategies for adult inclusion conjunctivitis (4)
Refer px + sexual partners to GP or sexual health clinic for lab test
Co-existing infections also need to be identified and treated
Mx of ocular signs+symptoms with topical tetracycline (note: does not treat full extent of systemic)
Oral medication critical: azithromycin 1gm PO or erythromycin 250mg QiD 2 to 6 weeks
What is the main problem associated with trachoma?
While it is a mild infection, the problem comes with repeated reinfections in poor hygeine areas. People can get up to 200 reinfections. Can lead to blindness due to this
List the symptoms of trachoma (3)
onset in early childhood with early FB sensation
often unilateral (initially), mucopurulent discharge with prolonged, remittent course (appears recurrent)
scarring trachoma leads to trichiasis, dry eye and reduced vision due to corneal opacities
What might early trichiasis lead to for the patient on presentation? (1)
significant corneal pain
What are the signs of trachoma? (5)
main sign: superior bulbar + palpebral conjunctival follicular response
chronic inflammation (over many years), causes:
- conjunctival scarring (e.g. Arlt’s line)
- corneal infilitrates
- superior corneal pannus
- scarring of limbal follicles (Herbert’s pits)
What is the main cause of blindness in people with trachoma? (1)
Trichiasis
In trachoma grading, what do the following acronyms stand for: TF TI TS TT CO
TF: trachomatous inflammation, follicular TI: trachomatous inflammation, intense TS: trachomatous scarring TT: trachomatous trichiasis CO: corneal opacity
What ddx exist for trachoma? (4)
adult inclusion conjunctivitis
other causes of conjunctival cicatrisation
other causes of recurrent conjunctivitis
other causes of superior corneal pannus
How do you tx trachoma? (5)
ID source of exposure
Refer for surgical tx
Corneal grafts rarely successful
Inactive scarring requires topical lubrication + other dry eye mx approaches
Prevention: improved hygeine, access to clean water, fly reduction programs
Do you treat a community that has endemic trachoma with azithromycin?
No you have to deal with the hygeine first. Otherwise, the people you treat will just get it again from poor hygeine and/or others in the community. So you’d have to keep treating them which would build up potential azithromycin resistance
Can anterior and posterior blepharitis coexist?
yes. Often these 2 conditions can coexist
What proportion of blepharitis patients have posterior blepharitis? Is posterior blepharitis more common or less common than anterior?
About 70-90% of blepharitis patients have posterior blepharitis (so posterior is more common)
How can we differentiate anterior blepharitis (i.e. blepharitis ocurring on anterior lamella) from posterior? (2.5)
Can use:
- Marx’s line (grey line posteriorly)
- skin on anterior surface
So a simple way to tell if it’s anterior is to see if the blepharitis is anterior to the grey line. If it’s anterior to the grey line that means it’s anterior blepharitis (note: delimited = marked boundary)