Elektron Technology HENSON 8000, User Manual, Page: 51 / 159

51 Visual field tests
© 2017 Elektron Technology
3 .2 .4 .3 De fe ct
Defect values are the difference betw een the measured threshold and that
expected from an age-matched normal eye.
They are presented in tw o different forms:
Absolute values in decibels (dB).
Symbols representing the probability that the threshold measure comes
from a normal eye. The probability values take into account the
variability in threshold estimates at each test location.
Positive values indicate a higher than average sensitivity.
T he a b o v e f ig ur e s ho ws the D e f e c t (le f t) a nd P a tte r n d e f e c t (r ig ht) v a lue s
a s s e e n in the s ta nd a r d p r into ut. A b s o lute v a lue s a t the to p a nd
p r o b a b ility s y m b o ls b e lo w.
Example:
If the measured threshold w as 25dB in a person of 40 years of age and the
normal value for that location w as 30dB, then the defect value w ould be -5dB.
Defect values appear on the standard printout and can be displayed on the
screen at the end of the test by pressing the defect button.
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