Confrontation Visual Fields

• Visual field: the perceptual space available to the fixating eye

• Purpose: to provide a gross check for any defects in the peripheral visual field

• Extinction phenomenon

  • Patients with right parietal lesions can exhibit a form of visual extinction. When shown two objects, one contralateral (left) and one ipsilateral (right) to the lesioned hemisphere, subject will report seeing only the one in the ipsilateral (right) field

• Riddoch’s phenomenon

  • Some patients with neurological defects suffer from stato-kinetic dissociation

    • Moving objects are perceived better than static ones

    • Defects present on automated perimetry (static) tend to be more extensive compared to those measured by manual perimetry (kinetic)

• Finger counting

  • Tests the patient’s ability to correctly identify gross targets in each of the 4 major quadrants

  • Procedure

    • Examiner and patient remove spectacles

    • Sit at eye level and 1m away

    • Have patient occlude OS with palm of their hand and fixates clinician’s OS with their OD (clinician’s visual field corresponds to the patient’s)

    • Place one hand in the mid-plane (50 cm) at about 45° from fixation

      • Important to be exactly between you and the patient so the patient’s field can be compared to yours

        • Fingers more than 50 cm from patient patient’s field will be underestimated/constricted

        • Fingers are less than 50 cm from patient field will appear to be normal but you may be more likely to miss a defect/constriction

    • Present one, two, or four fingers in one of the four quadrants

    • Repeat for other 3 quadrants

    • Present both hands simultaneously in both superior quadrants

    • Present the fingers of both hands and ask patient to add together

      • Do NOT use the same numbers in each hand

    • Repeat for OS

    • Record normal fields as FTFC (full to finger counting) OD, OS

      • If not full, then document/draw constricted quadrant

  • Advantages

    • Sensitive to homonymous (neurologic) quadrantic and hemianopic VF defects

    • Fast and can be performed in any location

    • Can test for extinction phenomenon

  • Disadvantages

    • Results are not meaningful to the DMV

    • Sensitivity is not very high

    • Limits of the VF are not tested

• Field Limits

  • Compares known peripheral field limits to the patient’s peripheral field limits

  • Procedure

    • Patient removes spectacles and occludes OS; have patient fixate your nose

    • Move target (wand) from behind patient (non-seeing to seeing) toward the horizontal limit of the field

      • Test slightly above and below the temporal midline

    • Have patient tell you when it comes into view

    • Do the same for the superior and inferior visual field

      • Test on both sides of the superior and inferior midline

    • Test nasal side

      • Test on either side of the nasal midline

    • Repeat for OS

    • Record limits (ALWAYS record from the patient’s perspective)

      • Normal