terminology and guidelines for glaucoma ii - Kwaliteitskoepel

HODAPP CLASSIFICATION 31
EARLY GLAUCOMATOUS LOSS
a) MD > - 6 dB
b) Fewer than 18 points depressed below the 5% probability level and fewer than 10 points below the p < 1% level
c) No point in the central 5 degrees with a sensitivity of less than 15 dB
MODERATE GLAUCOMATOUS LOSS
a) -6 > MD > -12 dB
b) Fewer than 37 points depressed below the 5% probability level and fewer than 20 points below the p < 1% level
c) No absolute deficit (0 dB) in the 5 central degrees
d) Only one hemifield with sensitivity of < 15 dB in the 5 central degrees
ADVANCED GLAUCOMATOUS LOSS
a) MD < -12 dB
b) More than 37 points depressed below the 5% probability level or more than 20 points below the p < 1% level
c) Absolute deficit ( 0 dB) in the 5 central degrees
d) Sensitivity < 15 dB in the 5 central degrees in both hemifields
1.4.5 - WORSENING OF THE VISUAL FIELD
Looking for visual field progression is the most important part of clinical management in chronic glaucoma because
this is the outcome that affects the patients quality of life. Changes in the visual field will make the Physician consider
a change in clinical management The identification of visual field progression requires a series of fields, usually more
than three, and often 5 or 6. Diagnosing visual field progession on a shorter visual field series is risky, because of the
inherent variability in patient responses. The exception would be a dramatic change that was associated with corresponding
symptoms suggesting visual loss and confirmed by unquestionable changes in ONH/RNFL. In many instances
of such sudden change, the cause will not be glaucoma, but either vascular in origin, or due to changes in the visual
pathways.
Recent Treatment/No Treatment trials (see Introduction) have shown that glaucomatous field progression is usually
slow, and that it will rarely be detected within one year of followup, even with a strict test/retest regime. In clinical practice
there will be an individual approach, with stricter follow up being indicated in cases with advanced disease or with
VF defects close to fixation. A practical scheme is to perform 2-3 tests that ‘train’ the patient, and provide mean values
for a baseline, and then to repeat testing twice a year. A clinical routine that involves less frequent testing will reduce
the chances of identifying change.
Reduced sensitivity in a cluster of test points on the same hemifield, and outside the periphery by >=5db, or a single
test point by > 10 db needs confirmation. This confirmation needs to be obtained on 2 subsequent field tests before
deemed a permanent change.
As an example, when using the Glaucoma Change Probability Maps in the Humphrey perimeter, at least three points
flagged as significantly progressing that occur in the same location in three consecutive examinations can be used to
define ‘confirmed’ glaucomatous field progression; the same pattern occurring in two consecutive fields can be used to
denote ‘tentative’ field progression.
Ch. 1 - 29 EGS