terminology and guidelines for glaucoma ii - Kwaliteitskoepel

A retinal sensitivity value worse than normal is indicated by a negative symbol in Humphrey perimeters (mean deviation)
and a positive symbol in Octopus perimeters (mean defect).
• PSD or LV (pattern standard deviation or loss variance): this is the standard deviation or variance of the deviations
and is thus a measure of the degree to which the shape of a patient’s field differs from a normal, age-corrected, reference
field. Thus the PSD or LV indicate the extent of focal loss in the visual field. The PSD or LV can be normal in
cases where there is diffuse loss and they are not good indices for the follow up of advanced glaucoma.
•SF (short term fluctuation): this indicates variability during a test at points that are tested twice; it is generally higher
in fields with glaucomatous damage. SF is thus an index of the patient’s consistency during the test period.
•CPSD or CLV (corrected pattern standard deviation or corrected loss variance): this indicates the extent of focal loss
in the visual field, taking short term fluctuation into account.
•Probability indices : abnormal global indices are presented with a probability denoted p < ‘x’%, indicating that there
is ‘an ‘x’% chance that this index is in reality normal.
Bebié Curve or Cumulative Defect Curve (Octopus, Peridata): the 59 points tested at full threshold (in the G1 program) are
ranked from the highest to the lowest sensitivity after age correction. A curve is obtained where the points on the left
represent the better points in the visual field and those on the right the worse points 13 .
When the sensitivity loss is diffuse most of or all the curve is not within the 95% prediction interval of the
normal population curve.
When the sensitivity loss is localised, and the sensitivity at some points is normal and at others abnormal, the
patient’s curve is within normal limits on the left and drops down sharply to the right.
Glaucoma hemifield test: this compares each of 5 groups of test points tested in a hemifield with the corresponding group
in the opposite hemifield. It is reported as abnormal, borderline or normal 14 .
DIAGNOSTIC CRITERIA FOR GLAUCOMATOUS VISUAL FIELD LOSS
(in the absence of retinal or neurological disease affecting visual field)
Visual field loss is considered significant when:
a) abnormal Glaucoma Hemifield Test, confirmed on two consecutive tests 15 , or
b) 3 abnormal points confirmed on two consecutive tests, with p < 5% probability
of being normal,
one of which should have p < 1%, all being not contiguous with the blind spot,
c) CPSD < 5% if the visual field is otherwise normal, confirmed on two consecutive tests.
Any defect or suspected defect must be confirmed by repeated testing.
1.4.4 - GRADING SYSTEMS 16
Scoring based on defect extent and on proximity of the defect to fixation point
Hodapp and co-workers proposed a classification in three stages considering MD value, number of depressed test sites on
the pattern deviation map and the presence of defect sites within the central 5°. This type of scoring needs an accurate
analysis of visual field which is useful but time-consuming 17 . It emphasizes the closeness of defective points to the fixation.
Grading based on kinetic perimetry
Aulhorn and Kermeyer ‘s classification based on kinetic and profile static perimetry patterns includes five stages of
increasing severity, according to visual field defects extension and morphology 18 .
Ch. 1 - 27 EGS