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Test Parameters and Strategies

Humphrey Field Analyzer II-

series User Manual 2660021145640 A

4-4

Test Strategies

One of the most important test parameter settings is test strategy. For both screening and threshold

testing, the strategy you use can affect the total test time and the precision to which the

measurements are made. The strategy also dictates whether screening test results are displayed as

qualitative (symbols) or quantitative (decibels) information. All threshold strategies yield quantitative

results. Each measures the threshold at every test point. The test strategies differ as shown in the

tables below. Refer to both Table 4.1 and Table 4.2 for a more detailed explanation of the test

strategies, as well as for information about the other

screening and threshold parameters. 

Table 4.1 Screening Test Parameters

(Factory default parameter settings appear in bold print.)

Screening

Parameters

Parameter

Settings

Description

Test Strategy Two Zone For each point in the test pattern, a stimulus is presented 6 dB brighter

than the expected hill

of vision. Printouts display circles (O) for seen stimuli

and boxes (■) for missed stimuli. Since screening is done with an intensity

6 dB

brighter than the expected threshold, missed points are known to be

at least 6 dB deep.

Three Zone Same as Two Zone, except each missed point is measured again at a

maximum in

tensity of 10,000 apostilbs (0 decibels) to determine if the

defect is absolute. Printouts display circles (O) for seen stimuli, “X’s” for

relative defects, and boxes (■) for absolute defects.

Quantify Defects Same as Two Zone, except the sensitivity at each missed poin

t is measured

relative to the expected threshold. Printouts display circles (O) for seen

stimuli, and numbers (in decibels) to indicate the depth of any defects. The

greater the number, the lower the retinal sensitivity (deeper the defect).

Test Speed Normal Two stimulus presentation speeds are available.

Slow You may change the test speed while a test is in progress to allow the

patient some additional time to respond.

Zeiss Humphrey II-i series User Manual

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