AED - Wet Eye - Week 2 Flashcards
How thick is the tear flim? Describe each layer, where it comes from, and how thick they are.
Total thickness is ~7.15μm
Lipid phase - meibomian glands - ~0.1μm
Aqueous phase - lacrimal glands and conjunctiva - ~7μm
Mucoid phase - goblet cells - ~0.05μm
What does lid action do to the tear flim?
Pushes it to the drainage sites
What do meibomian secretions aid in, and what may it limit?
Aids in spreading and may limit overflow
What forms in the eye concerning the tear film?
A lacrimal lake at the margin of the bottom eyelid
Describe all the structures of the lacrimal drainage system (5).
At the nasal margin of the eyelids is found two puncta (one for each eyelid) which drains into a canaliculus. These two canaliculi merge nasally to form the common canaliculus.
This drains into the naso-lacrimal sac.
This drains into the naso-lacrimal duct.
At the bottom of this duct is the valve of hasner.
What two forces draw tears into the naso-lacrimal sac?
Lid and capillary action
Where does the nasolacrimal duct drain to?
The back of the nose
What does the valve of hasner prevent?
Backflow
Define epiphora.
Tear overflow from the ocular surface
List three possible mechanisms of epiphora.
Tear overproduction
Poor tear support / movement
Impaired tear drainage
List 3 symptoms of epiphora.
Watery eye
Slight discomfort
Blurred vision
What can be said of epiphora if it is worse in cold/windy conditions (2)?
Usually anatomical / obstructive
What can be said of epiphora if it is worse in hot/dry conditions (2)?
Usually overproduction / dry eye related
List 5 signs of epiphora.
Increased marginal tear prism
Lid anomalies
Drainage blockage
Dry eye
Stenosed (narrowed) puncta
List 11 history questions you would ask for epiphora.
Age?
True tear spillage or just poor vision?
When are symptoms worse?
Associated discomfort?
Previous therapy?
Previous CNVII related events, tearing while eating?
Medication?
Red eye/discharge/crusting/allergies?
Pain/swelling?
Surface trauma?
Lid or conj. trauma/surgery/scarring?
When doing a slit lamp examination for epiphora, list 5 things to look out for.
Facial characteristics - entropion/ectropion
Normal lid movement
Lacrimal gland swelling
Punctal conformation/patency
Ocular surface condition
List 4 techniques (aside from slit lamp) that can be used to assess epiphora.
Lacrimal sac expression (pressure)
Lacrimal lavage (irrigation)
Fluorescein tests
Cotton thread/schirmers test
What is the normal range for schirmers test?
≥15 mm
List 4 tertiary techniques that can be used to work up an epiphora presentation. Briefly describe the purpose of each test if applicable.
Intranasal examination
X-ray or CT scan - inspection of drainage anatomy
Dacryocystography - radio-opaque dye and x-ray
Dacryoscintigraphy - radiolabel and gamma camera
List possible causes of tear overproduction.
Foreign body
Corneal/conjunctival irritation (allergy/infection/dry eye)
Intraocular inflammation
Refractive error (asthenopia)
Nasal irritation/inflammation
Psychological/emotional/environmental
Drug-related
Neural dysfunction/tumour
What does management of tear overproduction involve?
Managing the underlying condition
List three possible causes of poor tear film support.
Poor apposition of punctae
Obstruction of tear movement (conj. scarring/irregularity)
Lid pumping deficiency
-neuromuscular/ectropion/entropion
Define ectropion and entropion.
Ectropion - eversion of the eyelid, away from the eye
Entropion - inversion of the eyelid, towards the eye
What is ectropion/entropion commonly due to?
Age-related CT degenerative changes
List 4 signs and symptoms of ectropion (aside from lid alignment).
Hyperaemic palpebral conjunctiva
Watery/gritty eye
Droopy lower eyelid, exposing palpebral conjunctiva
Reduced TBUT
List two treatment options for ectroption.
Protection of ocular surfaces with tear supplements
Surgical correction
List 4 signs and symptoms of entropion (aside from lid alignment).
Gritty/watery eye
No visible lashes
Epithelial disturbances (SPK/ulcers)
Hyperaemia of the bulbar conjunctiva
List three treatment options for ectroption.
Tear supplements
Tape lower lid
Surgical correction
Can entropion be epilated?
Only if localised
Are optometrists generally able to treat underlying causes if epiphora is due to poor tear film movement?
Rarely, although topical therapeutic management with eyedrops may be necessary
List 5 obstructions that can result in impaired tear drainage.
Punctae
Canaliculae
Lacrimal sac
Nasolacrimal duct
Intranasal obstruction
List 6 possible causes ofimpaired tear drainage.
Congenital
Trauma
Inflammation/scarring
Drug-related
Infection
Tumours
What is the general management of impaired tear drainage (2)?
Identify and treat underlying cause as appropriate (referral if necessary)
Lacrimal probing and irrigation under topical anaesthesia
What can repeated lacrimal probing/irrigation lead to?
Further stenosis
Is canaliculitis a common or rare condition? Is it unilateral or bilateral?
Rare, unilateral
List 5 signs and symptoms of canaliculitis.
Unilateral epiphora
Chronic mucopurulent conjunctivitis that resists treatment
Pouting of puncta
Chalky granules expressed from canaliculi
Lavage indicating canalicular obstruction
Consider canaliculitis. If lavage indicates an obstruction, is further probing recommended?
Contraindicated
What is the treatment for canaliculitis (2)?
Refer
Appropriate antibiotic treatment
Define dacryocystitis and whether or not it is unilateral.
Unilateral infection of the lacrimal sac
List 4 signs and symptoms of dacryocystitis.
Pain
Swelling
Cellulitis
Mucopurulent discharge
What can be said of chronic dacryocystitis? What is it often secondary to?
It may have painless welling and is often secondary to a blockage of the nasolacrimal duct.
What is the treatment for dacryocystitis (3)?
Refer
Topical and systemic antibiotics
Warm compresses
Is lacrimal lavage/probing recommended in dacryocystitis? Explain.
Contraindicated due to risk of infection spread
List 5 causes of nasolacrimal duct obstruction in children. List the most common one first.
Failure of the valve of hesner to open normally at or near the time of birth
Absent punctum
Narrow/stenotic system
Infection
Nasal bone that obstructs the tear duct from entering the nose
