COT Visual Field Testing 2 — Questions and Answers
Question 1: Which visual field test strategy presents stimuli at threshold levels determined by prior responses, making it more efficient than full threshold testing?
- SITA Standard (Correct answer)
- Goldmann kinetic
- Confrontation testing
- Amsler grid
Correct answer: SITA Standard
SITA (Swedish Interactive Thresholding Algorithm) Standard uses statistical modeling to estimate thresholds faster than traditional full threshold strategies.
Question 2: A patient shows a visual field defect that respects the horizontal midline and corresponds to the inferior retina. This pattern is most consistent with:
- Glaucomatous arcuate scotoma
- Altitudinal defect from anterior ischemic optic neuropathy (Correct answer)
- Bitemporal hemianopia
- Central scotoma from macular disease
Correct answer: Altitudinal defect from anterior ischemic optic neuropathy
Altitudinal defects that respect the horizontal meridian are classic for anterior ischemic optic neuropathy (AION), affecting the superior or inferior half of the field.
Question 3: On a Humphrey Visual Field printout, what does the Pattern Deviation plot show?
- Raw sensitivity values at each test location
- Sensitivity values corrected for generalized depression (Correct answer)
- The expected normal values for patient age
- Comparison of right vs. left eye results
Correct answer: Sensitivity values corrected for generalized depression
The Pattern Deviation plot removes overall sensitivity depression (e.g., from cataract), revealing localized defects more clearly.
Question 4: Which stimulus size is the standard default for automated static perimetry on the Humphrey Field Analyzer?
- Goldmann I
- Goldmann II
- Goldmann III (Correct answer)
- Goldmann V
Correct answer: Goldmann III
Goldmann Size III (0.43° diameter) is the standard stimulus used for automated threshold perimetry on the Humphrey Field Analyzer.
Question 5: A patient's visual field shows a defect in the right eye's temporal field and left eye's temporal field simultaneously. This bilateral temporal loss suggests a lesion at the:
- Right optic nerve
- Optic chiasm (Correct answer)
- Right optic tract
- Left occipital cortex
Correct answer: Optic chiasm
Bitemporal hemianopia results from compression of the optic chiasm where nasal fibers from both eyes cross, typically caused by a pituitary tumor.
Question 6: What is the primary purpose of using a blue stimulus on a yellow background (SWAP) in visual field testing?
- Test rod photoreceptor function
- Detect glaucomatous damage earlier by isolating short-wavelength pathways (Correct answer)
- Assess color vision deficiencies
- Reduce test time compared to standard white-on-white
Correct answer: Detect glaucomatous damage earlier by isolating short-wavelength pathways
Short-Wavelength Automated Perimetry (SWAP) isolates the blue-yellow pathway, which may show deficits earlier in glaucoma than standard white-on-white testing.
Question 7: During automated perimetry, what is the significance of a high false positive rate (>15%)?
- The patient is not seeing the stimuli clearly
- The patient is responding when no stimulus is present, making results unreliable (Correct answer)
- The patient has reduced contrast sensitivity
- The test was performed under photopic conditions
Correct answer: The patient is responding when no stimulus is present, making results unreliable
A high false positive rate indicates the patient is pressing the response button even when no stimulus appears, making the field appear artificially better than it is.
COT Visual Field Testing 2
Which visual field test strategy presents stimuli at threshold levels determined by prior responses, making it more efficient than full threshold testing?