Preferential Hyperacuity Perimetry (PHP)6

ForeseeHome uses a patented technology called Preferential Hyperacuity Perimetry (PHP). Hyperacuity, or Vernier acuity, is the human ability to perceive small differences in the relative spatial localization of two objects in space.

During a PHP test, stimuli are successively flashed in various locations of the visual field. A typical stimulus consists of a series of dots, the majority of which are aligned with each other. A few dots are misaligned, creating the perception of a wave or artificial distortion in an otherwise straight line.

ForeseeHome uses PHP to detect tiny changes in the central visual field, including metamorphopsia and scotoma

The brief presentation ensures that cortical completion is not engaged and that fixation is maintained during the entire presentation of each stimulus. The presentation of the signal is triggered when the patient is fixating on the center of the screen.

The patient’s task is to mark the location where the distortion was perceived. When the stimulus is projected on an unhealthy area of the retina, the patient may perceive two distortions: one corresponding to the artificial wave and the other to the patient’s pathological distortion. Or, they may only see one distortion corresponding to the pathological distortion


The ForeseeHome AMD monitor is designed as a closed viewer for single-eye examination. A set of lenses embedded within the viewer ensures that the test is viewed as if projected from infinity, such that a patient with good distance vision sees the test in maximal focus. The patient starts the test by inserting his/her head within the viewer. A pair of infrared sensors located in the walls of the viewer detects the position of the head relative to the hood and ensures that the test is not presented until the head is correctly positioned. The tested eye may be alternated from left to right by a half cycle rotation of the viewer.

Patients are instructed to test their prescribed eye(s) daily, and their responses are automatically transmitted to the Notal Vision Diagnostic Clinic at the end of each test. The wireless communication technology facilitates fast and reliable transmission of data, which is then made available to the physician through a secure website. Tests are continuously compared to a normative database threshold and the patient’s own baseline. When a statistically significant change of test patterns is detected, the DMC alerts the clinic so that they can schedule a prompt clinical examination with the patient.

In addition to monitoring test scores, the frequency of use is also tracked. To encourage patients to test at an adequate frequency (i.e., one that will allow timely detection in a conversion event), the DMC will contact the patient if no results are received for 7 consecutive days.

AMD=age-related macular degeneration.

FDA Indication for Use

The ForeseeHome is intended for use in the detection and characterization of central and paracentral metamorphopsia (visual distortion) in patients with age-related macular degeneration, as an aid in monitoring progression of disease factors causing metamorphopsia including but not limited to choroidal neovascularization (CNV). It is intended to be used at home for patients with stable fixation.

The ForeseeHome AMD Monitoring Program is only available by physician order and is intended to be used as an addition to regular eye exams.

The technical component of the ForeseeHome AMD Monitoring Program is covered by Medicare, subject to its coverage requirements for the test, to assess patients with dry AMD who are at risk of developing wet AMD. Please refer to your local Medicare Administrative Contractor (MAC) for which the ordering physician resides concerning coverage availability for the physician professional services component of the test.