Glaucoma: VF Exam

Question 1

Automated Alternation Flicker: Fundus Photo taker: What does it do?

Answer 1

Basically, it takes a photo from a previous time and superimposes it onto the new photo, then ALTERNATES b/w the 2. This allows you to see the difference between the two.

Question 2

Visual Fields: Hill of Vision

1. Peak Retinal Sensitivity of what? (dB)

Answer 2

1. 30 dB

Question 3

VF Changes in Scotomas:

1. What are the differences b/w Relative and Absolute Scotomas?
2. What are ARCUATE SCOTOMAS (Bjerrum Scotoma)
   a. Most common to occur in what quadrant?
   b. This correlates with what?
   c. What if you have Focal Notching at Both Superior and Inferior POLES (what is it called)?
   d. What do Scotomas start as?

Answer 3

1. Relative: Some retinal Fibers are damaged but not all, so you get some response.
   a. ABSOLUTE: NO RESPONSE
   b. Fluctuating…b/w the 2.
2. Scotoma starts at Blindspot and ARCHES above or below Fixation w/respect to HORIZONTAL RAPHE!!
   a. Inferior Temporal Quadrant (NOTCHING)
   b. Superior half of VF.
   c. DOUBLE ARCUATE SCOTOMA
   d. PARACENTRAL DEFECTS, then become more DENSE and LARGER

Question 4

VF Changes in Scotoma (2)

1. Paracentral Scotoma
   a. w/in that degrees of CENTRAL?
   b. Most common in what area?
2. In Glaucoma: what should we think about?
3. Nasal Step
   a. Loss of Axons rarely proceed at the same rate comparing what areas of the RNFL.
   b. It’s a “STEP like” Defect at what LOCATION?
   c. MOST OFTEN LOCATED where?
   d. They begin usually as what?

Answer 4

1. a. 5-15 degrees (may precede start of Arcuate Scotoma)
   b. NASALLY; due to Partial Notching
2. HALLMARK: ASYMMETRY b/w 2 EYES. and ASYMMETRY b/w SUP and INF VFs. When we get to the Horizontal Raphe, we notice a BIG DIFFERENCE (so normal up to it, then a reduction of loss or serious loss. MOST COMMON SUPERIORLY than INFERIORLY)
3. a. Comparing Superior and Inferior RNFL
   b. At the HORIZONTAL RAPHE
   c. SUPERIORLY due to Inferior nerve fibers being more commonly damaged.
   d. Isolated Scotomas in the Periphery

Question 5

VF: changes in Scotomas (3)

1. General Depression
   a. Is it common?
   b. What is it?
   c. If this is seen, what 3 things should you consider it might be?
   d. *A 20-40% of Ganglion cell fibers are lost due to glaucoma. will this result in major issues with VFs?

Answer 5

1. a. RARE
   b. General, homogenous VF loss that manifests as uniform decrease in sensitivity

c. Cataract/Media; Miosis; Refractive Error
d. Not necessarily. Pt could have full VFs

Question 6

VF: Threshold Testing Strategies

1. Which should we use today: Full threshold, SITA Standard, SITA Fast?

Answer 6

1. SITA Standard: doesn’t take as long as full threshold (rarely used now); uses an ERF (error related factor): Allows for some error. (SITA FAST is faster but allows for a lot more error, so no bueno.)

Question 7

VFs: Issues

1. Fixation Losses: 20% of losses is considered what?
2. False Negative: What is it?
   a. Normal Field w/High false?
   b. Abnormal Field: High False?
3. False Positives: What is it?
4. So, in the long run, which is more important: False Negatives or False Positives?

Answer 7

1. a sign of unreliability; but there is NO real standard set for this.
2. Patient doesnt respond to a stimulus that should have BEEN EASILY SEEN
   a. Should interpret as Abnormal (but is could be due to glaucomatous loss…have to look at everything as a whole)
   b. Pt responds w/a ton of variability in Abnormal regions.
3. Trigger happy; Also do to patient responding too fast or too slow..
4. FALSE POSITIVES = INVALID VF; False negatives could be high and results could still be valid.
   * No published criteria (but >10% False positive is usually what is considered Unreliable)

Question 8

VF: Print Out

1. Raw Data
2. Gray Scale
3. Total Deviation
   a. Negative?
4. Total Deviation Probability Plot
5. What does Total Deviation Tell us?
   a. Pupillary Miosis/Mydriasis will more likely cause a Generalized Depression?
   b. Can a VF be done on a patient is undilated/dilated?
   c. Uncorrected refractive error of 1D = what in depression?

Answer 8

1. Actual threshold measured (dB)
2. Pictoral representation of Raw Data
3. Number value that compares data to Age-Corrected Values
   a. Below median normal.
4. Number value of Total Deviation converted into a Probability. (DARK = t be able to see what they missed)
5. If we have a Generalized/Depression (Cataracts/Pupil Size, uncorrected Refractive Error)
   a. Pupillary Miosis
   b. YES. Just not while patient is DILATING
   c. 1dB depression in Retinal sensitivity

Question 9

VF: Print Out (2)

1. Pattern Deviation
2. Pattern Deviation Probability Plot
3. What is the Best Clinical Indication of a True VF Defect?
4. When looking at these plots, what is more indicative of pathology?

Answer 9

1. Adjusts for generalized depression to determine Localized depression (Deviation corrected for Overall Height of Hill of Vision)
2. Numeric Value converted into Probabilities
3. Pattern Deviation/Probability Plot
4. CLUSTERS of abnormal points. (not just a few scattered points)

Question 10

VF: Print Out (3)

1. Mean Deviation
   a. What is it?
   b. What does a MD of -10dB mean?
   c. If Mean deviation is OUTSIDE NORMAL RANGE, what is determined?
2. Pattern Standard Deviation: What does it tell you?
   a. In Glaucoma, is it smooth or Localized depression usually?
   b. What would we expect the PSD to look like in ADVANCED GLAUCOMA?
3. What is the GLOBAL INDEX that INDICATES FOCAL FIELD LOSS?
4. Abnormal MD w/NORMAL PSD means what?
5. If MD worsens and PSD stays about the SAME, what is WORSENING?
6. If MD is STABLE and PSD WORSENS what do we expect is PROGRESSING?
7. If BOTH MD and PSD are WORSENING, what do we expect?
8. Early to Moderate Glaucoma: what will PSD do?

Answer 10

1. a. Basically a Weighted average, where Points CLOSER TO FIXATION count more than PERIPHERAL POINTS
   b. Overall sensitivity of VF Loss of -10dB over the Entire VF (+ value is RARE!)
   c. a Probability Value is determined
2. If the reduction is Smooth over the entire Hill of VISION or a LOCALIZED DEPRESSION
   a. USually LOCALIZED (we would Expect HIGH PSD = Localized IRREGULARITIES)
   b. Probably a NORMAL PSD cuz everything is DEPRESSED so no difference b/w Sensitivity VALUES!
3. PSD
4. DIFFUSE LOSS (probably due to a CATARACT!) Unlikely that it’s from Glaucoma
5. WORSENING CATARACT
6. Progressing GLAUCOMA
7. CATARACT AND GLAUCOMA are WORSENING!
8. Increase which means WORSENING Glaucoma with GREATER FOCAL DEFECTS

Question 11

VF: Test

1. Glaucoma Hemifield Test
   a. What does it do?
   b. What is a HALLMARK of GLAUCOMATOUS VF LOSS?

Answer 11

1. a. Goups fields. Then looks at DIFFERENCES b/w UPPER and LOWER HEMIFIELDS
   b. SENSITIVITY differences b/w UPPER and LOWER HEMIFIELDS!

Question 12

Tons of VFs that can be run.

1. Which is recommended?
   a. WHY?
2. How many VFs are needed?
3. Definition of Glaucoma According to VFs ALONE? (HPA Classification (study)): Need 1 of the FOLLOWING!
4. 2 Big things to diagnose glaucoma?
5. HPA Glaucoma Study
   a. Early Defect: Meet 3 Criteria (all 3 have to be met)
   b. Moderate Defect: 4 Criteria need to be met
   c. Severe (Only 1 of these required) (4)

Answer 12

1. 24-2: 54 test points: 24 degrees in each direction EXCEPT 30 degrees NASALLY
   a. SET up SPECIFICALLY FOR GLAUCOMA!
   * SHORTER than SITA as well.
2. No standard accepted yet. Most say 2-3 at least. Some studies say 3 cuz first VF is usually TRASH
3. Glaucoma Hemifield Test: Outside NORMAL LIMITS on 2 VFs, or Cluster of 3+ Continguous Non-edge points p-6dB; Less than 25% below 5% level and -12dB; Less than 50% (37 pts) below 5% level and

Question 13

Humphrey VF: Determining Progression

1. GPA
   a. What does event mean?
2. VFI
   a. What does rate look at?

*Progression Rate: What is so important about it?

Answer 13

1. Event Based Analysis
   a. Compares Baseline to Most recent data
2. Rate Based Analysis
   a. How fast the reduction is progressing over an amount of time.

*Most important thing to determine therapy and future visual impairment/future progression rate

Question 14

Humphrey Progression Analysis

1. Baseline Exam
2. VFI Value
3. VFI Rate of Progression Analysis
4. VFI Plot
5. VFI Bar
6. Current VF Summary
7. GPA Alert
8. Purpose of Guided Progression Analysis
   a. Uses ALGORITHM from what TRIAL?
   b. How does it analyze? (compares to what?
   c. What tests can it be used on?

Answer 14

1. Establish Initial VF of Pt
2. Summary that show’s Pt’s VF Status compared as a % of Normal-age VFs
3. Trend of overall VFs of the Pt
4. Regression Analysis of VFI Values and a 3-5 yr projection
5. Graphic depiction of Pts useful Vision at current VFI Value w/3-5 yr projection
6. Complete Report showing VFI, MD, PSD, Progression Analysis Plot, and GPA Alert
7. Tells us if there has been Statistically Significant Deterioration seen in the Consecutive Tests
8. Help identify Clinically significant Progression of VF Loss in Patients w/Glaucoma!
   a. From EARLY MANIFEST GLAUCOMA TRIAL!
   b. Highlights Changes from baseline exams that are larger than the typical clinical variability in PTs w/similar DEGREES of GLAUCOMA!
   c. Full threshold (baseline only), SITA standard and SITA Fast

Question 15

Guided Progression Analysis

1. Open Triangles
   a. What does it look at?
   b. %?
2. Half-Filled Triangle: Identifies what?
   a. Signifies what?
3. Filled Triangle: Identifies what?
   a. Signifies what?

Answer 15

1. Points that have CHANGED beyond normal variability AT LEAST ONE TIME
   b. Points that have gotten worse than most variable 5% (so p

Question 16

VFs Analysis

1. VFI: Purpose?
   a. Number that’s better?
   b. Basically it does what?
   c. Need a minimum of how many exams over how many years?
   d. Slope of MD from all exams used to determine Regression Analysis: Allows what?

Answer 16

1. Overall percentage of how Pt compares to Normal Age-adjusted Population
   a. Higher number the BETTER (100%): 0% means you’re Perimetrically Blind
   b. It QUANTIFIES the RATE of PROGRESSION relative to Pt age
   c. Min of 5 EXAMS over 3 YEARS required to have VFI Plot

d. Us to determine Rate of Progression (Great concept, but Glaucoma progression is usually NOT LINEAR!)

Question 17

VFs:

1. Frequency DOUBLING TECHNOLOGIES (FDT)
   a. Use
2. Short Wavelength Automated Perimetry (SWAP)

Answer 17

1. a. Becoming more mainstream!
   * Target as Flickering of a linear background until Pt can detect doubling of the Background. Appears to correlate w/Conventional Perimetry but hasn’t shown to be more sensitive yet.

• RESISTANT to environmental factors like Blur, refractive error and room illumination.
  2. It’s a Blue-yellow VF. (stimulate different Ganglion cells). NOT WIDELY USED!