Zeiss Humphrey Field Analyzer 3, Инструкция по эксплуатации

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HFA3 Instructions for Use 2660021166131 Rev. A 2018-11
Data, Tests & Reports
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6-12
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Report Features
Reliability Indices
Blind Spot Errors (Fixation Losses/FL)
Blind Spot Errors are recorded when Blind Spot monitoring is active and occur when a patient
responds to a stimulus presented in the blind spot. The number of responses is recorded over the
total number of stimuli presented. A high error rate may mean poor patient fixation during the test
or that the blind spot was located incorrectly. Fixation Losses > 20% are indicated by a double X.
False Positives (FP)
False Positive errors occur when a patient responds too quickly to a stimulus or in the absence of a
stimulus. In SITA tests False Positives are not calculated until the end of the test and a percentage >
15% will be indicated by a double X. A percentage > 33% will be indicated for non-SITA tests. A
high score suggests that the patient may be overly concerned about not seeing all the stimuli.
Patients that respond inappropriately may also have abnormally high threshold results.
False Negatives (FN)
A False Negative is recorded if the patient does not respond when a stimulus is repeated at a
particular location and at a level much brighter than has already been seen.
Note: Reports will display only one message with the priority given to high False Positives and the
message “Excessive High False Positives”. Otherwise, the message “Low Test Reliability” is displayed
on SITA test reports if Fixation Losses are > 20%. For non-SITA tests, the same message will display
if either the number of Fixation Losses are > 20% or False Negatives are > 33%.
Grayscale and Numeric Formats
The Grayscale format depicts the size and depth of any present field defects. Each pattern variation
corresponds to a 5 dB change in sensitivity. The comparative scale in Table 4-2 displays the ten (10)
Grayscale patterns and relates them to decibels and apostilbs.
Note: The Grayscale in SWAP printouts often looks significantly darker because SWAP testing
normally generates lower threshold sensitivity values than does white-on-white testing. The
maximum (0 dB) stimulus in SWAP testing is 6 foot-lamberts, not 10,000 apostilbs.
Total Deviation Plots
The numeric values in the upper total deviation plot represents the difference in decibels (dB)
between the patient’s test results and the age-corrected normal values at each tested point.
The lower total deviation plot, called a probability plot, translates the values from the upper plot
into shaded symbols indicating the highlights points falling below specific percentile levels
1 – Reliability Indices 3 – Defect Depth
2 – Grayscale Results 4 – Numeric (dB) Results
SYM
ASB
0.8–
0.1 2.5–1 8–3.2 25–10 79–32 251–
100 794–
316 2512–
1000 7943–
3162 >
10000
DB 41–50 36–40 31–35 26–30 21–25 16–20 11–15 6–10 1–5 < 0
Table 6-2 Grayscale Symbols and Numerical Equivalents in Apostilbs (ASB) and Decibels (dB).