Flashcards in Lec 10 Deck (29)
What gland(s) produce the lipid layer?
What gland(s) produce the aq layer?
Accessory and main lac lacrimal gland
What gland(s) produce mucous layer?
conj goblet cells
What are the 3 components of the tear system
Production, Distribution, Drainage
How much of our tears are passed via the nasolacrimal drainage system?
__ gland = basic secretion
___ gland = reflex and psychogenic stimulation
accessory gland = basic, main lacrimal gland = reflex/psychogenic
Basic secretion ___ the normal volume of aq layer and ____ with age
What is the efferent pathway?
General Visc Efferent fibers from CN 7 --> pterygopalatine ganglion --> hitchhike with V2 (zygomatic)---> infaorbital fissure --> lacrimal N (v1)
What cranial nerve predominantly carries the efferent pathway for lacrimation?
What cranial nerve predominantly carries the afferent pathway for lacrimation?
What is the afferent pathway for reflex tears?
Cornea/nasal mucous --> long/short ciliary n --> nasociliary n --> V1 --> pain signal to Trigeminal Ganglion --> lacrimal nucleus --> facial n
(then Efferent pathway)
What is the corneal reflex triad
Lacrimation, blinking (due to facial n. nucleus stimulation), Miosis (stimulation of EW nucleus)
What are the possible causes of epiphora?
Hypersecretion of tears (2ndary to irritation of ocular surface), outflow obstruction at level of puctum or nasolac duct or sac
Overall = imbalance between production, distribution, drainage
What is another word for tear meniscus
What is the set up to examine tear prism?
thin parallelpiped, med illum, tall beam, 10-1x, white (though enhanced with fluorescein and cobalt blue)
What is a normal tear meniscus height?
High viscosity is more like water or peanut butter?
Soapy tears is indicative of what?
increased fatty acids in tears, MGD
Describe: Schirmer Tear Tests
gross estimate of aq volume of tears, indicator of tear production (typically to confirm lack of tear production)
What does Schirmer I test for?
tear production of basic + reflex?
What would a Schirmer I value of 4 mm indicate? Would you hve to do a Basic secretion test too?
severely abnormal. Nope
What tools do you need to perform Schimer II compared to I
II also requires topical anesthetic, cotton tipped applicator
What are normal/mild/mod/severe for Schirmer I?
Normal >15, Mild reduction 10-15, Moderate 5-10, Severe <5mm
What is a normal value for basic secretion?
> 10 mm
What is a normal value for SchirmerII
Normal > 15 mm
What does Schirmer II test for?
What does TBUT identify areas of?
T/F: TBUT of > 10 is normal