Week 7 - Lacrimal Flashcards
the two mechanism for epiphora
Over-production
Drainage system disorder
What should your slit lamp examination involve
1) examine for ectropion/entropion
2) blepharitis or meibomian dysfunction
3) tear meniscus height
4) punctal placement
How to examine for Nasolacrimal duct obstruction
Palpation - with your fingers and ask the patient if it is painful
- also look out for lumps, nodules, masses
What does white pus discharge from the puncta indicate?
inflammation
what does red (blood) discharge from the pucnta indicate?
tumour
What does the Jones 1 test determine?
Used to determine retention of tear
obstruction in drainage apparatus
What does a positive Jones 2 test indicate?
Functional blockage lower than puncta or canaliculi
What does a negative Jones 2 test indicate?
Negative for NaFl & Px reports saline in throat = NaFl never entered drainage system in Jones 1.
Functional blockage at puncta or canaliculi
What are the advantage of lavage therapy?
Serves as a diagnostic and therapeutic purposes
- flushes mucous plugs, concretion from lacrimal drainage system
- epiphora resolves instantly if blockages flushed out
How to manage tear overproduction?
- treat the condition causing excess tear
- dry eye management
How to manage canaliculitis?
- warm compress and massaging
- infection requires oral antibiotics - risk of orbital cellulitis
How to manage dacrocystitis?
Warm compresses and massage
topical antibiotics
chronic dacrocystitis - curettage and antibiotic irrigation
How to manage an obstruction lower than the lacrimal sac?
Surgical intervention - dacrocystorhinostomy
What is the histology of the caruncle?
Stratified, non-keratinised squamous epithelium
Contributes to tear film and the filtering of debris
What is the histology of the canaliculi?
Non-keratinised
Stratified squamous epithelium surrounded by elastic connective tissue
What is the histology of lacrimal sac?
Lined with double layer of columnar epithelium
What is the histology of the nasolacrimal duct?
double layer of coloumnar epithelium
what is the function of the Rosenmuller valve?
Prevents reflux from nasolacrimal sac into canaliculi
What is the function of the Valve of Krause?
Prevents reflux between the lacrimal sac and the nasolacrimal duct
What is the function of the Valve of Hasner?
Prevents reflux from the nasal meatus
Tear drainage in relation to the muscles
Horner’s muscle contributes to positive pressure on lid closure
On lid opening there is negative pressure into the lacrimal sac which draws tears
Valves in the system prevent reflux
Where are T and B cell found?
T and B-cells are found in concentrations just below the epithelia connected by specialized vessels
What are CALTS
Conjunctiva-Associated lymphoid tissue
Can be within the conjunctiva and lacrimal sac
Represent a mechanism to detect infection in the lacrimal drainage apparatus
Which muscle is important for exerting pressure on the globe during blinking?
The pretarsal and preseptal portions of the orbicular muscle exert pressure on the globa during blink
