Schirmer Tear Test

  1. What is the lipid layer and where is it?
    • outer layer
    • from sebaceous (Meibomian) glands lining eyelids
  2. What is the water layer and where is it?
    • middle layer
    • from tear (lacrimal) glands
  3. What is the mucus layer and where is it?
    • inner layer
    • from goblet cells in conjunctiva
  4. What are the different causes of KCS?
    • autoimmune (immune system tries to destroy the tear glands)
    • congenital (defective tear glands)
    • trauma
    • drug reaction
    • viral infections
    • hormone imbalance
    • idiopathic
  5. What does KCS stand for and what is it?
    • Keratoconjunctivitis sicca
    • dry eye
  6. What is STT?
    standard measurement of aqueous tear production
  7. What do we use STT for?
    • to evaluate animals with ocular discharge and irritation
    • to diagnose KCS
    • to evaluate a patient with epiphora (tear overflow) - to determine if increased volume or decreased outflow is the problem
  8. What does STT stand for?
    Schirmer Tear Test
  9. Is interpreting the STT difficult?
  10. When we are interpreting the STT what must it correlate with?
    the clinical signs
  11. What can cause tear production to vary?
    • stress
    • animals are stressed in the vet clinic so it can affect the test
  12. Why should we do repeated STT?
    to evaluate if it is transient or permanent KCS
  13. When we do repeated tests, why do we need to use the same brand for each repeated test?
    because the different brands vary in absorbency
  14. How do we perform the STT?
    • remove excess mucopurulent discharge prior to testing (a dry cotton tipped swab may be used)
    • strip is bent at notch and placed over lower lid
    • keep strip in place for 1 minute
    • then measure the amount of wetting in millimeters
  15. What unit of measurement do we use for STT?
  16. What are the normal values for the STT in dogs and cats?
    • dogs:  equal to or greater than 15
    • cats:  equal to or greater than 16.9
  17. What is marginal or early subclinical KCS?
    • dog:  11 - 14
    • cat:  5 - 11
  18. What is mild to moderate KCS?
    • dog:  6 - 10
    • cat:  5 - 11
  19. What is severe KCS?
    • dog:  <5
    • cat:  <5
  20. What are the two ways to treat KCS?
    • medical
    • surgical
  21. What are the medical ways to treat KCS?
    • artificial tears
    • cyclosporine
  22. What are the surgical ways to treat KCS?
    • parotid duct transposition
    • superficial keratectomy
  23. What is the purpose of artifical tears?
    • keep the eye moist
    • slightly viscous
  24. How do we use artificial tears?
    apply at least every 2 hours
  25. What is cyclosporine?
    • stimulates tear production
    • powerful immune system response suppressor - restores natural tear production
  26. What product is cyclosporine?
  27. How do we use cyclosporine?
    ointment put in eyes twice a day
  28. When we apply the cyclosporine to the eye what does it do?
    prevents the immune system from destroying the tear glands
  29. Does cyclosporine affect the rest of the patient's immune system?
  30. Is cyclosporine effective if tear glands have been comletely destroyed?
  31. What does a parotid duct transposition do?
    • move rostral end of parotid salivary durt to conjunctiva
    • patient is literally "spitting in his own eye"
  32. What are some complications of parotid duct transposition?
    • not enough saliva
    • runny eye at mealtime
    • dental tartar in eye
  33. When would we do a parotid duct transposition?
    only if medical treatment does not work
  34. What can chronic KCS cause?
    can cause pigment to accumulate on the surface of the cornea
  35. When do we do superficial keratectomy?
    for chronic KCS and only if KCS is under control at the time of surgery
  36. How do we do a superficial keratectomy?
    outer layer of the cornea can be removed to get rid of the pigment that accumulates on the surface of the cornea
Card Set
Schirmer Tear Test
Clinical Practice ll