Compass is the first Fundus Automated perimeter capable of performing standard 24-2 visual field testing, delivering TrueColor confocal images at the same time.

COMPASS is a scanning ophthalmoscope combined with an automatic perimeter that provides confocal images of the retina, as well as measurements of retinal threshold sensitivity, under non-mydriatic conditions.

Fundus Automated Perimetry

Fundus automated perimetry is a technique that images the retina during visual field testing, enabling a correlation to be made between visual function and retinal structure.

Advantages of Fundus Automated Perimetry over Standard Automated Perimetry include the possibility to measure sensitivity at specific retinal locations, higher accuracy thanks to retinal-tracking based compensation of eye movements and the simultaneous assessment of function (expressed by retinal sensitivity) and structure (images of the ONH, of the RNFL and of the retina). Fundus Automated Perimetry provides a simultaneous, quantitative assessment of fixation characteristics.

Use of Fundus Automated Perimetry in the clinical management of glaucoma has been limited so far, as available systems were lacking compliance with the standards of automated perimetry. COMPASS overcomes such limitations and brings visual field analysis to the next level!

In particular COMPASS, for the first time, extends field coverage to 30° + 30° and employs luminance parameters and a sensitivity scale as used in standard automated perimetry.

Benefits

    High-resolution TrueColor Confocal Imaging of the ONH, of the RNFL and of central retina
    Combined structure and function analysis
    High test – retest repeatability thanks to the Real Time Retinal Tracking, that actively compensates eye movements
    Reliable automated follow up with combined structure-function progression analysis
    Comprehensive printout
    Operator friendly: no trials lens required, automatic refractive correction
    More patient comfort: test can be suspended at any time without data loss

Key Features

    Extreme ease of use: patient auto-sensing, auto-alignement, auto-focus
    Auto flash adjustment, auto-capture
    Compact & clean design
    High quality images
    Minimal training required
    No additional PC required
    Touch-screen operation
    Internet-native

Compatibility to standard 24-2 visual field testing:

As a perimeter, the system offers full compatibility with standard 24-2 visual field testing and contains an age-matched database of retinal sensitivity in normal subjects.

Retinal Tracking:

Retinal tracking is at the heart of Fundus Automated Perimetry.

Infrared images, acquired at the rate of 25 images per second, allow for continuous, automated, tracking of eye movements. Determination of eye movements yields to Fixation Analysis, where the location of the functional site of fixation and its stability are computed.

Fixation analysis is unique to Fundus Automated Perimetry. Retinal tracking also yields to active compensation of fixation losses, with perimetric stimuli being automatically re-positioned prior to projection based on the current eye position. This mechanism is critical to ensure accurate correlation between function (i.e. retinal threshold values) and structure (retinal appearance).

Compensation of eye movements takes place before and during the projection of a certain stimulus. In absence of this mechanism, a normal 2-3 degrees shift in eye position occurring at the time of projection of a certain stimulus would easily produce an artifact in VF results, with a wrong sensitivity being reported at that specific location.

Retinal Imaging:

As a retinal imager, COMPASS uses a confocal optical system, similarly to SLO systems, to capture TrueColor images and to provide Red-free images of superior quality. In addition, a high resolution live image of the retina obtained using infrared illumination is available throughout the test.

SLO systems are superior to conventional fundus cameras in many ways, as they exploit a confocal imaging principle, which limits the effect of backscattered light from deeper layers and provides enhanced image quality in terms of contrast and resolution. Another major advantage of SLO systems is that they operate with much smaller pupils than non-confocal instruments.

At the same time, though, SLO systems do not provide color images, as they typically employ monochromatic laser sources, resulting in black and white or pseudo-color images. Differently from existing SLO systems, Compass uses a white light LED instead of monochromatic lasers, hence providing TrueColor images and offering high fidelity to real retinal appearance.

Compass images offer:

•     no need for pupil dilation (pupil down to 3 mm)
•     Wide field (60° degrees in a single capture)
•     excellent resolution, contrast and sharpness
•     high quality even in presence of media opacities, such as cataract
•     optimized exposure of the ONH

Fundus Perimetry    
Projection field    30° (radius)
Background luminance    31.4 asb
Maximum luminance    10000 asb
Dynamic range    0 - 50 dB
Stimulus size    Goldmann III (26”)
Stimulus duration    200 ms
Threshold tests    24-2, 10-2
Fixation control    25 Hz automated retinal Tracking
Foveal threshold testing    
Automatic pupil measurement