Zeiss HUMPHREY 720i User Manual - page 15

INTRODUCTION / INSTRUMENT SETUP

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HUMPHREY FIELD ANALYZER II -

 i

series

Blue-Yellow (SWAP) testing

Blue-Yellow perimetry, also known as Short Wavelength Automated Perimetry, or SWAP,

(model 745i and 750i)

has performed better than standard computerized perimetry according to published

longitudinal studies. Working independently, researchers from U.C. Davis and U.C. San Diego

have found that Blue-Yellow perimetry identified early glaucomatous visual field defects years

before they could be detected using standard white-on-white perimetry.

Blue-Yellow perimetry differs from standard static White-on-White perimetry only in that a

carefully chosen wavelength of blue light is used as the stimulus, and a specific color and

brightness of yellow light is used for the background illumination. For more information on

Blue-Yellow perimetry, see Section 4 and Section 7.

Automatic fixation monitoring

The HFA II employs several methods for ensuring that patients maintain proper fixation of the

target during testing. All models are equipped with a video eye monitor which presents a view

of the patient’s eye on-screen so that users can ensure proper patient fixation. Every HFA II also

offers standard Heijl-Krakau blind spot monitoring.

Models 740i, 745i and 750i also offer Gaze Tracking: a patented, high precision system which

uses real-time image analysis to verify the patient is looking at the fixation target and not

looking around. The gaze tracking device is unaffected by the patient’s head position. A

continuous record of fixation is available for monitoring on the test screen throughout the test.

The gaze track graph is included on the printout to provide a permanent record of the patient’s

fixation.

For patients who require a trial lens, the model 750i uses Head Tracking and Vertex Monitor-

ing to help ensure that the patient’s eye is both centered behind the lens and is held at the

proper distance from the lens. These features help to eliminate the trial lens as a possible

source of unreliable visual field results.

Data protection features

Visual field results need to be saved and protected for future use. The HFA II offers you a

number of data storage methods to file the results. Floppy disk data storage is available with all

models of the HFA II. Magneto-optical disk backup is available on the model 750i of the HFA II

and is optional with other models. There are a number of additional data protection features

that work internally to safeguard your data from serious loss or damage. This User’s Guide

describes in great detail the procedures for creating extra copies of your data.

Information on the internet

New information about your HFA II may be found on the Carl Zeiss Meditec web site.  The

internet address is : www.meditec.zeiss.com

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