Lecture 9: VF/Function Specific Perimetry Flashcards
____ is the central detection and monitoring of visual function in glc
Perimetry
Physiological blind spot is about __ degrees temporal from fixation
15
What is the hill of vision?
- Optic Disc Imaging, RNFL Analysis and Ganglion Cell Analysis
- Axons of the optic nerve fibers are contained in the RNFL
___ is the clincal standard for measuring glaucomatous VF defects
Standard Automated Perimetry (SAP)
- Clinical standard for measuring glc VF defects
- Glaucomatous loss detected/managed more reliably compared to manual perimetry
- Uses static perimetry
- Threshold sensitivity presented in decibels (dB)
- 0 dB = bright intensity
- Values of 30 dB are normal values
- Value are relative and not directly comparable across different makes of perimeters
What is suprathreshold technique
- Relatively quick to administer
- Record whether a location is normal (stimulus seen) or abnormal (not seen)
- Uses a stimulus 4-6dB brighter than expected threshold
- Chooses from age-matched database
- follows expected hill of vision
What is the best technique for glaucoma evaluation? What’s the con of using this test?
Full threshold.. IT TAKES SO LONG to do
- uses 4-2 staircase method
What are the 2 types of full threshold technique? What is the difference between each test?
-
Fastpac
- Reduces test time at the expense of measurement accuracy
-
SITA
- Reduces test time while maintaining standard of accuracy used in 4-2 threshold testing
- Takes about 7 mins per eye
- 2 types: SITA standard & SITA fast
SITA standard is designed for
- Designed for glc - do not use it with other conditions
- Interchanging SITA with conventional full-threshold is not recommended in longitudinal follow up of patients
- SITA is becoming new gold standard for threshold perimetry in glaucoma
- Quicker test is naturally appealing
- Sound research suggests measurement from SITA are in close agreement with full threshold
- SITA defects do appear shallower
SITA FAST is good in subjects who..
have difficulty completeting a long VF test
- Uses larger step sizes
- Makes it even qucker in time
- NOT a great choice for f/u care
- really only use clincailly if pt have difficulty physically/mentally performing standard test
List 5 Patient dependent factors.
What are the other factors? (5)
- Fatigue effect - difficult to control
- Inattentiveness - false negative
- Trigger happy - false positives
- Fixation loss
- Learning Curve
Other factors
- Refractive error
- Trial lens artifact
- Pupil size
- droopy eyelids
- Media opacities/tear film irregularities
Field loss (SAP) is an indicated for what?
advanced disease
If early in disease what test would you order & how often would you repeat testing?
- Baseline 24-2 HVF, consider baseline 10-2
- Repeat at least every 6 months
- Follow the ONH and OCT closely for change
If late in disease what test would you order & how often would you repeating testing?
- Follow the 24-2 VF closely for change
- Repeat at least every 3 months
- May need to follow 10-2 closely as well
- Continue to monitor ONH and OCT
What are the common glaucomatous VF defects?
- Arcuate
- Nasal step
- Paracentral
- Diffuse?
T/F a normal VF does not exclude glaucoma
TRUE, but it does exclude advanced disease
Approximately __ of RGC lost before 5-10DB of VF reduction
40%
fibers from the ___ retina usually most susceptible to damage
temporal
Damaged NFL typically give isolated damage in the ___ areas (__ - __ degrees). Eventually forming ____.
paracentral; 10-20
Arcuate scotomas
Early non-specific changes produces what type of visual field loss?
generalized constriction
Early significant changes produces what type of visual field loss
- Peripheral nasal step
-
Small wing shaped paracentral scotoma
- Within Bjerrum’s area
- Isolated or associated with nasal step
-
Siedel’s sickle-shaped scotoma
- Paracentral scotoma
- Joins blind spot

What does the image represent? Describe each.

- Schematic showing worsening patterns of VF loss in open-angle glaucoma
- A. Location of testing points of 24-2, Humphrey VF
- B. Isolated defects in paracentral area
- C. Small isolated defects combin to form a larger defect
- D,E. Arcuate defect forms and worsens and eventually breaks through to the periphery
- F. End-stage defect, with only small functoinal macular area remaining
What type of VF loss does this represent?

Paracentral scotoma
What type of VF loss does this represent?

Arcuate scotoma (Bjerrum)










