Static and kinetic visual field testing. Reproducibility in normal volunteers
R. K. Parrish 2nd, J. Schiffman and D. R. Anderson
The SD of static visual threshold ranges from 0.12 log units near fixation
to 0.41 log units 30 degrees from fixation. Among 60 points tested, most
persons have at least one point that tests 0.5 log units less sensitive
than the adjacent points, simulating a scotoma 0.5 log units deep. With
automated kinetic perimetry, the SD of isopter position is 2.6 degrees to
5.5 degrees, with the greatest variation appearing in the temporal field
where the slope is flatter and the isopters are more peripheral. More than
10% of the points show an inward deviation of 5 degrees or more compared
with their neighboring points. Retesting of the deviant points is required
to distinguish an artifact caused by variable responsiveness from true
localized defects. Judgments about progression also require that the
accuracy of the isopter position or threshold determination be taken into
account.
