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The Testing Screen (Figure E) allows you to prepare the patient for the test and to confirm or modify the testing configuration selections, if needed, prior to performing the visual field test.

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The status box under the chart on the right side of the screen shows that the Pre-test Demo is running. Until the test is started, stimulus presentations for the selected test are automatically displayed to demonstrate the test to the patient.

Confirm that the patient’s name, ID and date of birth are correct. Return to View Patients (F2) if changes are needed.

Confirm the desired Test Type is selected in the upper right of the screen. Also, confirm proper selection of the Folder, Test Speed, and Fixation Target. Refer to the System Settings section of this User’s Guide for more information. You can change each of these by using the pull down menu (click on the arrow to change if necessary).

You can alter the first eye tested in this screen by selecting the OD (RIGHT) or OS (LEFT) buttons above the chart.

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Figure (E)

In the Testing Screen, the video eye monitoring will display a live image of the patient’s eye to aid in proper alignment of the patient and to ensure fixation during testing. Selecting the FreezeButton will freeze the live image of the eye. This provides the capability to measure the pupil size using the increments on the cross hair in the frozen video image. The markings on the cross hair are in 1mm increments. Press the Unfreeze Button to return to live video.

VIEWING TEST RESULTS

You may view and print previous visual field test results for a particular patient by selecting a patient from the VIEW PATIENTS (F2) Screen and then selecting the Recall Tests Button. You may also select desired individual tests from multiple patients from the RECALL TESTS (F3)Screen by using the track pad. Use the track pad and select one test at a time, a section at a time by holding down SHIFT, or select multiple separate entries by holding down CONTROL and selecting each desired test with the track pad (see Figure F).

 

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Figure (F)

 

If you selected multiple entries, choose the pull-down menu at the top of the TEST DETAILSScreen (see Figure G) to select a specific test from all selected, or use the Previous or Nextbuttons at the bottom of the Test Details Screen to cycle through the selected tests. You may view the raw Threshold (dB) levels of the threshold test results, or you may use the pull-down menu above each chart to select various graphical representations of the test including:

Gray Scale Total Deviation Probability Plot Total Deviation (dB) Pattern Deviation Probability Plot Pattern Deviation (dB)

Note: Only the Total deviation probability plot is available for screening tests.

You may also select the OD (RIGHT) or OS (LEFT) eye button above both eye charts for the threshold tests to show two different graphical representations of the same eye (see Figure G)

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Figure (G)

 

Test data displayed includes Test Duration, Catch Trials, Mean & Pattern Deviation global indices with statistical significance, and GHT (for the 24-2 & 30-2 tests only). You may also recall and modify any Notes or test Information you previously entered for the selected test by selecting the appropriate tab below each chart. Select the More>> button at the upper right of the screen to view additional test information generated by the instrument.

The table below summarizes the various FDT visual field tests available on the Humphrey Matrix Visual Field Instrument. Sample printouts for all the tests listed are included at the end of this User’s Guide for your reference.

The screening tests provide qualitative results regarding the patient’s visual function. Screening tests are typically used for patients where no eye disease has been detected as part of a routine eye examination. Threshold testing is used to obtain quantitative visual field results to confirm the presence of eye disease and monitor visual function over time.

FDT Test

Visual Field Locations

Probability Level Classifications

Fixation Catch Trials

False Positive Trials

False Negative Trials

Test Strategy

N-30-5, N-30-1 Screening

19

4

3

3

0

Supra- Threshold

24-2-5, 24-2-1 Screening

55

2

10

10

0

Supra- Threshold

N-30-F Threshold

19

4

6

6

3

MOBS

24-2 Threshold

55

4

10

10

6

ZEST

30-2 Threshold

69

4

10

10

6

ZEST

10-2 Threshold

44

4

10

10

6

ZEST

Macula Threshold

16

4

6

3

0

ZEST

 

SCREENING TESTS

All of the Humphrey Matrix visual field FDT screening tests are supra-threshold tests meaning that they test at specific age-corrected contrast values determined by the normative database probability levels. Select the probability levels to use for screening for general clinical use to maximize sensitivity (-5 uses the 5% probability level) or for population based screening to maximize specificity (-1 uses the 1% probability level). The screening test results consist of probability plots of the tested locations for each eye and overall reliability measures along with patient and test information. The test locations indicate the different probability levels with different patterns, increasing in darkness with decreasing probability level. Refer to the sample printouts included at the end of this User’s Guide.

The N-30-5 (or N-30-1) FDT screening test is essentially the same 19-point rapid screening test performed on the Humphrey FDT Visual Field Instrument, except that moving the fixation target is not required with the Humphrey Matrix. The same normative database is used for the N-30 tests in the Humphrey FDT and Humphrey Matrix Visual Field Instruments so the tests are comparable between the two instruments. Each test location is assigned one of four probability levels, depending on the test selected. Each visual field location is tested until the patient responds, or until all three probability levels are tested. The initial probability level is tested twice if needed, followed by once at each of the other levels to complete the N-30 screening. As a result, the screening test time will increase for patients with eye disease.

The 24-2-5 (or 24-2-1) FDT screening test is a screening version of the 24-2 full threshold test. Each test location is assigned one of two probability levels, depending on the test selected. Each visual field location is tested at a single probability level (pass/fail). Each visual field location is tested until the patient responds or the location is tested twice at the initial probability level to complete the 24-2 screening.

All the Humphrey Matrix visual field threshold tests are full threshold tests meaning that they provide quantitative measures of the visual function at each location tested. The threshold test results consist of a raw threshold plot (dB values), a gray scale plot (pattern shading), total and pattern deviation plots (dB values), total and pattern deviation probability plots (pattern shading), MD and PSD global indices (numeric with probability values), overall reliability measures, along with patient and test information for each eye tested. The probability plots indicate one of five possible probability levels with different patterns, increasing in darkness with decreasing probability level. Refer to the sample printouts included at the end of this User’s Guide.

The N-30-F FDT full threshold test is essentially the same 19-point full threshold test performed on the Humphrey FDT Visual Field Instrument, except that moving the fixation target is not required and the threshold algorithm has been optimized to reduce test time with the Humphrey Matrix. The same normative database is used for the N-30 tests in the Humphrey FDT and Humphrey Matrix Visual Field Instruments so the tests are comparable between the two instruments.

For the N-30-F FDT full threshold test, the instrument utilizes a staircase threshold strategy known as a Modified Binary Search (MOBS). The Humphrey Matrix utilizes a four-reversals rule (N-30-F) for determining the threshold level. The range of possible threshold level values for the raw data (patient threshold scores) is between 0 dB Maximum Contrast (lowest patient sensitivity) and 56 dB Minimum Contrast (highest patient sensitivity). The formula used to

calculate the dB values is log × ⎛2048⎞ × 10 × H where c ranges from 1 (minimum contrast) to 204810 ⎝ c ⎠

(maximum contrast) and H is approximately 2. Note that XX dB is displayed if the threshold is not determined due to inconsistent patient responses which do not meet the MOBS threshold criteria. The magnitude of the threshold level values is directly correlated to the Humphrey Field Analyzer values.

The 24-2, 30-2, 10-2 and Macula FDT full threshold tests are modeled after the Humphrey Field Analyzer tests to provide visual field test results that are familiar to you. The FDT test results for the threshold tests correlate with the HFA results, but they are not directly comparable. The FDT tests use a large (~270 subjects for each eye) age normative FDT database. The FDT full threshold tests use a maximum likelihood threshold strategy known as a ZEST (Zippy Estimate of Sequential Testing) to provide accurate threshold results as quickly as possible. ZEST is similar to SITA used on the Humphrey Field Analyzers, but differs in the specific algorithm details.

The 24-2 (55-point) and 30-2 (69-point) FDT full threshold tests are central 30 degree visual field tests for use in general visual field testing and glaucoma management. These tests also provide a Glaucoma Hemifield Test that provides a plain language interpretation of the visual field results based on an asymmetry analysis between test locations in the upper vs. lower hemifield to detect glaucoma.

FDT isolates a subset of low redundancy, retinal ganglion cell mechanisms in the magnocellular (M-cell) pathway. These M-cells have large diameter fibers and comprise only 3% to 5% of all retinal ganglion cells. The damage to these cells in the disease process is detected effectively and efficiently by FDT. Refer to the Clinical Examples Reference Guide for more information.

The Humphrey Matrix Visual Field Instrument does not require scheduled calibration. The instrument calibration is automatically checked each time the instrument is powered ON and at the start of each test to be sure the unit is properly calibrated. If the instrument detects the need for calibration, the Operator LCD Display will display a needs calibration warning. If not calibrated when the needs calibration warning is displayed, the unit will continue to operate normally until the unit reaches the calibration limits. Once the calibration limits are reached, the unit will not operate normally until a calibration is completed successfully. Perform calibration at any time, not only when requested by the instrument. Calibration will take approximately 15 minutes to complete.

To calibrate the instrument, select the Help (F6) Screen, and then select the Calibration Button. Before selecting the Calibrate Button in the Calibration Screen (see Figure L), make sure the Patient Eyepiece is covered with the Calibration Cap. Once the Patient Eyepiece is covered,select Calibrate. There is a prompt to ensure the Patient Eyepiece is covered. If the Calibration Cap is not available, substitute something that will temporarily block light from entering the Patient Eyepiece (black cloth over Patient Visor, etc.) or perform the calibration in a completely darkened room. The Operator LCD Display will indicate if there is too much ambient light to complete the calibration. A Calibration Progress indicator is provided.

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Figure (L)