The Haag-Streit 301 is decisively a product of German engineering and largely bucks the status quo that Humphrey and other competitors have already set. In fact, much of the Octopus series is largely deviating from other Perimeters in terms of testing strategies, design and even interface. Although it’s run by three large stepper motors located within the optical head, the unit is surprisingly quiet- almost silent in fact- even when the motors are at work. Not even a fan can be heard running in the background and that is a big step up from the traditional Humphrey Field Analyzers which seem to be powering a jet engine inside. The entire optical head is easy to align given the on-screen controls, however the (fairly uncomfortable) chin rest and forehead rest mean more patient alignment is necessary prior to testing up front. The 301 does have some impressive auto-alignment features which track the gaze and pause testing when the patient moves or blinks though. Unlike the 301, competitors such as the Matrix 715, and Oculus Easyfield both align patients in a fixed position where manual positioning isn’t required. With that being said, the automatic maneuvering of the 301’s optical head means better fixation and more consistent gaze than the other units we just mentioned. The fixation monitoring real-time camera is also displayed quite largely on the 301’s testing interface. In terms of perimetry, the 301’s software basically offers all the tests you’re accustomed to, except with all different names and little explanation as to how they relate to tests you’re used with traditional Humphrey models. Instead of 30-2 and 24-2, etc… you’re offered Program G1 (2), M2, 32, ST, LVC which we recommend reading Haag’s ‘Visual Field Digest‘ to fully understand. 30° perimetry on the 301 offers both screening and full-threshold testing patterns all inside a fairly compact instrument with unique styling.
OUR TAKE: German engineering has us liking the concept of an auto-alignment “pre-test-esque” visual field however also leaves us wondering why the optical head ‘needs’ to move. A concept that competitors have ‘fixed’ — pun intended.
The examination unit can be rotated in any direction to permit operation from all sides depending on the floor plan. This allows installation and use in extremely tight spaces. The same principle of rotation makes it technically possible to follow pupil movements and correct fixation loss automatically. An exclusive feature of the Octopus 301 Series is a direct projection system. All its optical elements, the background, the stimuli, the fixation target and the camera are lined up through the same optical path. No false light from outside can disturb the examination because there is no bowl or cupola. Therefore, the Octopus 301 perimeters can be used in ambient light conditions and still provide reliable results.
Good eye fixation may be the most important element in support of the reliability of data. The Octopus 301 has a unique rotating optical head that allows the unit to follow the patient’s pupil automatically. This means that the eye is kept centered and fixation is always maintained.
The Octopus perimeters have diagnostic examination programs using different test grids in relation to the topography of the retina and underlying pathologies. Also, the examinations are run in stages prioritizing the most crucial field areas by testing the critical points first.
Longer examination times may result in errors caused by patient and retinal fatigue. Therefore, it is important to have a choice to employ in particular cases a fast test strategy with a significant reduction in time. The Dynamic strategy adapts the step size automatically to the depth of a defect. The time saving here is approximately 50%. The TOP Strategy (Tendency Oriented Perimetry) reduces testing time to just over 2 minutes for an examination using the program G1 test grid with 59 locations.
Never miss a point
Normal blinking prevents dry eyes and helps the patient to relax and concentrate during examination. With Octopus Blink Control, you need never worry again about missing a stimulus presented in static perimetry. Stimuli interrupted by the patient’s blinking are automatically repeated later during the test. This means that every test location is tested reliably.
Maintaining the correct pupil position during examination is essential for correct identification of the location of a defect. If the pupil position changes during stimulus presentation, due either to shifting of the head or eye movement, the Pupil Position Control pauses the examination automatically until the pupil is re-centered. This stimulus is automatically repeated later during the test. The result is a visual field that you can trust.
Configure your favorite printout and graphics representation, in order to reduce the time necessary to interpret the results.
Choose either the proven Octopus 7-in-1 printout containing the cumulative defect curve (Bebie curve) or the HFA-style printout.
Since the Octopus 301 works without a cupola, a fully darkened room is not required. In order, though, to make the examination conditions pleasant for the patient and for obtaining reliable results, the instrument is to be placed in the room so that no direct light falls on the instrument or the patient.
Programs G1, 32, M2, ST and LVC.
The Octopus 301 does communicate via RS-232C and Ethernet (LAN) communication protocol, however ask your EHR provider prior to purchasing.
The 301 is solely a white-on-white perimeter, where as the 311 provide blue-on-yellow stimulus’. The 311 also offers the ability to change stimuli presentation and some other minor software features.
Patient results can be viewed through the patient’s folder within the device’s database. It can of course also be printed out.