Visual fields

• What is the visual field?

  The area of one’s surroundings that is visible at one time, with a steadily fixating eye
• What are the different types of visual fields to consider?

  • Monocular vs. Binocular
  • Central vs. Peripheral
  • Relative vs. Absolute
• What is the central visual field extent for the right eye?

  ~30°
• What are the peripheral visual field extents for the right eye?

  • Temporal: ~100°
  • Nasal: ~60°
  • Superior: ~60°
  • Inferior: ~75°
• What is the purpose of the Amsler Grid?

  It is useful for detecting central scotoma/distortions (metamorphopsia)

  
• In what cases is the Amsler Grid indicated?

  In cases of central visual disturbance, such as unexplained decreased visual acuity and macular pathologies

  
• What is the most common use of the Amsler Grid?

  To monitor age-related macular degeneration

  
• What does metamorphopsia indicate?

  It may indicate subtle macular disorders, such as swelling
• What does a scotoma indicate?

  It indicates more severe retinal or optic nerve disease
• What are the different charts used in Amsler Grid testing?

  1. Chart 1: Standard 5mm square grid
  2. Chart 2: Similar to Chart 1 with diagonal lines
  3. Chart 3: Red grid for toxic amblyopias
  4. Chart 4: Scattered white dots for central scotomas
  5. Chart 5: White parallel lines for metamorphopsia
  6. Chart 6: Black lines on white card for metamorphopsia
  7. Chart 7: Additional squares for subtle macular disease

  
• What is the purpose of confrontation testing?

  It is a useful screening for large, absolute scotoma
• How effective is confrontation testing for detecting postchiasmal defects?

  It detects 9 out of 10 postchiasmal defects
• How effective is confrontation testing for detecting prechiasmal defects?

  It detects 1 out of 3 prechiasmal defects
• What is the minimum evaluation required for driving license requirements?

  Confrontation testing
• What are the steps for performing confrontation testing?

  1. Patient covers one eye and fixates on the examiner's eye.
  2. Test all four quadrants with hands ~50cm from the patient.
  3. Present both hands simultaneously.
  4. Instruct the patient to report the number of fingers seen.
  5. Test both hemi-fields twice for confirmation.
• What does neglect mean in confrontation testing?

  It means the patient keeps neglecting one quadrant when two are presented
• What does extinction mean in confrontation testing?

  It means the patient gets one quadrant right but fails to report the other when two are presented
• What is the purpose of red cap testing in confrontation?

  To screen the function of the optic nerve
• What is the procedure for red cap testing?

  Ask the patient to identify the color of the cap and rate its brightness compared to the other eye
• What are the two types of perimetry?

  • Static Perimetry
  • Kinetic Perimetry
• Why is perimetry essential in glaucoma detection?

  It measures visual function (sensitivity) outside the fovea
• How is perimetry useful for neurological disorders?

  It helps in the detection of neurological disorders
• What is the role of neuroimaging in visual field testing?

  It is used once a disorder is detected
• What is the most commonly used form of automated perimetry?

  Computerized perimetry
• What does static perimetry measure?

  It measures sensitivity to small white lights presented on a dimly illuminated background
• What are the different stimulus patterns used in static perimetry?

  • Grid pattern (e.g., Humphrey)
  • Radial pattern (e.g., Medmont)
• What is the difference between screening and threshold in static perimetry?

  Screening provides reasonable sensitivity for detecting defects, while threshold is used for confirming defects and monitoring
• What is the SITA standard in static perimetry?

  It is an adaptive psychophysical procedure for estimating sensitivity
• What is the Bjerrum screen used for?

  • Historic use for central scotoma
  • Limited to central 30° to 50°
  • Requires 3 targets to evaluate scotoma
• What is the Goldmann Perimeter known for?

  It is the first standardized perimeter
• What is the bowl radius of the Goldmann Perimeter?

  30 cm
• What is the background luminance of the Goldmann Perimeter?

  10 cd/m²
• What are the target configurations in Goldmann Perimeter?

  • Size
  • Color (Red, Blue, White)
  • Intensity
• How is the target size in Goldmann Perimeter defined?

  Target size is defined from 0 (smallest) to V (largest)
• What is the significance of reliability indices in perimetry?

  They help determine if the test results are reliable
• What do visual field global indices indicate?

  They provide an overview of the visual field performance
• What is the purpose of gaze tracking in perimetry?

  It records the patient's gaze during testing
• How do we interpret the results of perimetry tests?

  By analyzing reliability indices, threshold values, and global indices

  
• What are the key components of perimetry interpretation?

  • Reliability indices
  • Test strategy
  • Patient data
  • Test duration
  • Threshold values
  • Grayscale map
  • Numerical total deviation map
  • Visual field global indices