Test Results and Reliability Measures
Humphrey Matrix User Manual
2660021138935 Rev. F 2015-11
4-6
there is significant loss in one part of the field and not in others. MD is best inter-
preted in relation to the Total and Pattern Deviation plots.
Pattern Standard Deviation (PSD) is a measurement of the degree to which the shape
of the patient's measured field departs from the normal, age-corrected reference field.
A low PSD indicates a smooth hill of vision. A high PSD indicates an irregular hill and
may be due either to variability in patient response or to actual field irregularities.
Reliability Measures
When reviewing the results of the visual field test, give careful consideration to the
reliability indicators (catch trials). They are an important measure of patient reliability in
taking the test (and of the reliability of the results). They are indicated as a ratio of the
number responded to the number presented (as well as a percentage of the total). For
example, 1/10 (10%) indicates that the patient responded to 1 of the 10 catch trials
presented. If errors occur in greater than one third of the catch trials, the test results may
be unreliable.
Fixation Errors
The ratio of the number of times the patient responded to a target placed in the blind spot
versus the total number of times fixation was tested (i.e., total number of targets placed in
the blind spot). Fixation errors indicate the patient is not maintaining good fixation during
the test, is misaligned, or does not understand the test.
False Positive Errors
The ratio of the number of times the patient responded to a “pause” in the testing
sequence (i.e., no target presented) versus the total number of “pauses” in the testing
sequence. False positive errors indicate the patient is pressing the button even if the
patient does not see any patterns (trigger happy) or does not understand the test.
False Negative Errors
The ratio of the number of times the patient did not respond to a test pattern at the
maximum possible contrast level of the instrument versus the total number of times that
maximum possible contrast level patterns were tested. When possible, false negative catch
trials are only presented at locations where the patient has previously responded. False
negative catch trials are not used with screening tests. False negative errors indicate the
patient is likely not paying attention, does not understand the test, or has a severe loss at
the location of the false negative catch trial(s).
Содержание Humphrey Matrix 800
Страница 1: ...User Manual Humphrey Matrix Model 800...
Страница 26: ...Introduction Humphrey Matrix User Manual 2660021138935 Rev F 2015 11 1 20...
Страница 84: ...Viewing and Printing Tests Humphrey Matrix User Manual 2660021138935 Rev F 2015 11 6 18...
Страница 108: ...Networking Configuration Humphrey Matrix User Manual 2660021138935 Rev F 2015 11 8 18...
Страница 150: ...OfficeMate PMS Instructions Humphrey Matrix User Manual 2660021138935 Rev F 2015 11 B 2...
Страница 156: ...Error Codes Humphrey Matrix User Manual 2660021138935 Rev F 2015 11 D 4...
Страница 157: ......