Lecture 5: visual field progression and new types of perimetry

Question 1

Why is it important to monitor VF defect progression in glaucoma?

Answer 1

-can indicate best management option
-important in clinical trials for new treatments

Question 2

What are the disadvantages of global indices?

Answer 2

-data reduction
-No spatial info
-poor sensitivity

Question 3

What is GPA?
What is needed to do a GPA?
What are the disadvantages?

Answer 3

glaucoma progression analysis

-need 5 visual field plots to confirm change
dot: no change from baseline
white triangle: significant change
cross: too much variability
black triangle: true change
half white and back triangle: change confirmed at next visit

-dependant on baseline
-does not use all the fields

Question 4

What are the alternative perimetry techniques for assessing glaucoma?

Answer 4

*Glaucoma occurs much earlier than it can be seen by perimetry
*Magnocellular pathway responds to:
-high amounts of flicker
-achromatic stimuli
-Moving stimuli
-low spatial frequencies

Question 5

What is blue on yellow perimetry?

Answer 5

*Suggested it can detect visual defect earlier
*Cohort study showed its not better than current perimetry
*Longer Test
*+ Adaptation required
*More variability!
*Poor response in elderly
*Yellowing of crystalline lens with age

Question 6

What is the frequency doubling test?

Answer 6

*Flicker stimulus
*Low spatial frequency sinusoidal grating
*Didn’t turn out to be more effective than automated perimetry
*Well-designed instrument, liked by patients
*Called FDT matrix perimetry
*Doesn’t detect glaucoma earlier