the lacrimal system

Question 1

what is the function of the PTF?

Answer 1

prevents the eye from desiccation
allows transport of oxygen and nutrients to the cornea
lubrication of the eye surface
eliminated surface irregularities on cornea
washing out of foreign bodies

Question 2

what is epiphora?

Answer 2

failure of the drainage of the tears
anomaly of the lacrimal punctas and canaliculi
tear staining syndrome

Question 3

aetiology lacrimal puncta and caniculi anomalies?

Answer 3

1. developmental abnormalities

2. Acquired

Question 4

developmental defects preventing tear drainage?

Answer 4

atresia, imperforatio, ectopy

Question 5

acquired defects of tear drainage?

Answer 5

obstructions
- inflammatory (rare), foreign bodies

traumatic injuries

Question 6

treatment of anomaly of lacrimal punches and canaliculi?

Answer 6

surgery

- repair of imperfect puncture by using pressurised fluid

Question 7

what is the outcome of failure to produce normal PTF?

Answer 7

contamination of foreign materials within the eyes surface 
keratoconjunctivitis sicca (KCS)

Question 8

name the three layers of PTF?

Answer 8

1. lipid: secreted by eyelid glands in eyelid margin
2. water (aquamucin) - thickest layer: the lacrimal glands of the third eyelid
3. mucin: by goblet cells of the conjunctiva

Question 9

what is quantitative KCS?

Answer 9

change in volume of PTF

Question 10

what is qualitative KCS?

Answer 10

change in quality of PTF

- failure In lipid/ mucin layer of PTF

Question 11

aetiology of KCS?

Answer 11

idiopathic 
autoimmune 
KCS with systemic diseases 
chronic blepharoconjunctivitis 
drug induced; intoxications
surgically induced 
trauma 
neurogenic 
canine distemper 
congenital

Question 12

systemic diseases producing KCS?

Answer 12

polyarthritis, colitis, diabetes mellitus, hypothyroidism, Cushing’s
immunocomplexes in the blood destroy the tear film

Question 13

chronic blepharoconjunctivitis causing KCS?

Answer 13

scar formation at the site of the openings of the lacrimal gland

Question 14

causes of drug induced KCS?

Answer 14

long term therapy with sulphonamides
after (local) general anaesthesia
exotoxins

Question 15

surgically induced causes of KCS?

Answer 15

after removal of the prolapsed third eyelid gland (or entire third eyelid)

Question 16

trauma causes causes of KCS?

Answer 16

affecting the tear glands directly or via their nerve supply

Question 17

neurogenic causes of KCS?

Answer 17

neuropathy of n. trigeminus

Question 18

how can canine distemper cause KCS?

Answer 18

the virus is lacrimotoxic to the lacrimal gland and to the gland of the third eyelid

Question 19

which breed suffers most with congenital KCS?

Answer 19

Yorkshire terrier

Question 20

signs of acute KCS?

Answer 20

pain, blepharospasm, prolapse of the nicitans
dry, lustreless cornea
corneal ulceration: pathognomic to acute KCS - helps us to differentiate

Question 21

signs of chronic KCS?

Answer 21

hyperaemic, velvet like conjunctiva
dry opaque cornea
keratinisation of the cornea (and conjunctiva)
chronic staphylococcal infection

Question 22

diagnosis of KCS?

Answer 22

clinical signs
shimmer test, rose bengal test
qualitative KCS: Fluorescein stain
examinations for systemic disease

Question 23

therapy for KCS?

Answer 23

cannot be cured
medical
some surgical approaches
lifelong therapy

Question 24

medical therapy to KCS?

Answer 24

initial length of therapy is 3 months
artificial tears (increase volume)
Improvement of quality - combination of: artificial tears; hyaluronate content tears; vazelin; Vit. A ointment
controlling of secondary infections - topical ABs, corticosteroids
inhibition of immune mechanisms - cyclosporine
washing of the eye to remove excess discharge

Question 25

surgical therapy of KCS?

Answer 25

parotid duct transposition!