The Zeiss HFA-II 750 perimeter has grown to be apart of the older generation of visual fields produced from Carl Zeiss Meditec, however it still holds the basic Goldmann principle that even the latest ones possess. Although manufacturers may try to sell you on a newer one, little in regards to the actual perimetry principles has changed. While you do not get galucoma progression analysis, nor EHR connection capabilities, you do get a visual field machine that performs all the tests you’d ever need to treat your patients and bill their insurance. Although more expensive in comparison to it’s little sisters (740, 745), this unit does offer “head tracking” which keeps the patients head and gaze aligned and alerts the technician if something is askew. This reduces the observation requirement from the tech.
OUR TAKE: Buy this if you want to bill for perimetry, and enjoy the benefits of blue-yellow-red stimulus, and gaze/head tracking however are indifferent to the latest spaceship Zeiss offers.
What mainly sets the HFA-II 750 apart from its lesser siblings is the head tracking feature. This allows the operator to truly walk away from the device as the test is delivering and still get reliable results. If the patient takes their head away, it will notify the technician. During the test, the 750’s user-interface displays a real time video of the eye (and takes pupil measurement) allowing near perfect alignment of the patient prior, and during the test. The 750 also maintains features seen in lesser units, including red-yellow-blue perimetry, and Gaze tracking.
Standard automated perimetry, which tests the visual field with a white stimulus against a white background (W-W perimetry) detects a visual field defect when about 40% of the retinal ganglion cells (RGCs) have been lost. It is preferable to detect damage at earlier stages of ganglion cell loss, given the irreversible nature of vision loss in glaucoma. Hence, the HFA-II 750 comes to the rescue. Blue-on-Yellow Perimetry (B-Y), also known as Short Wavelength Automated Perimetry (SWAP), can detect early visual field loss before a reduction in differential light sensitivity is seen with standard white-on-white (W-W) perimetry since there is an association between glaucoma and short-wavelength (blue) color vision deficits. SWAP is standard on the HFA-II 750.
We include a HP Laserjet 6C Printer with the purchase of the HFA unit. You can add a double top table to your purchase using the variations options prior to checking out.
It depends on the test, however most full threshold tests on HFA units take anywhere from 3-6 minutes per eye.
In general, the HFA units are relatively patient friendly however most do not dream of visual field testing. Elderly patients may find it difficult to maintain gaze, however the machine reads and understands this through false-negatives.