(141 days)
The CenterVue COMPASS is intended for taking digital images of a human retina without the use of a mydriatic agent and for measuring retinal sensitivity, fixation stability and the locus of fixation. It contains a reference database that is a quantitative tool for the comparison of retinal sensitivity to a database of known normal subjects.
The CenterVue COMPASS is a scanning ophthalmoscope combined with an automatic perimeter that allows the acquisition of images of the retina, as well as the measurement of retinal threshold sensitivity and the analysis of fixation. The device works with a dedicated software application, operates as a standalone unit, integrates a dedicated tablet, a joystick, a push-button and is provided with an external power supply. COMPASS operates in non-mydriatic conditions, i.e. without the need of pharmacological dilation and is intended for prescription use only.
The Centervue COMPASS device operates on the following principles:
- An anterior segment alignment system is included, which uses two infrared LEDs with a centroid wavelength of 940 nm and two cameras, whereas the former illuminate the external eye by diffusion and the latter allow a stereoscopic reconstruction of the pupil's position, used for automated alignment purposes via pupil tracking;
- An infrared imaging system captures live monochromatic images of the central retina over a circular field of view of 60° in diameter, by an horizontal line from an infrared LED with a centroid wavelength of 850 nm and by an oscillating mirror which scans the line to uniformly illuminate the retina; such images are in turn used for auto-focusing purposes and to track eye movements, providing a measure of a patient's fixation characteristics and allowing active compensation of the position of perimetric stimuli;
- A concurrent color imaging system allows the capture of color images of the central retina over a circular field of view of 60° in diameter, using a white LED and a blue LED combined to obtain a white light illuminating the retina by the same scan mechanism;
- A fixation target projecting onto the retina a fixation target obtained from a green LED;
- A stimuli projector, projecting onto the retina white light Goldmann stimuli at variable intensity and allowing measurements of threshold sensitivity at multiple locations, according to a patient's subjective response to the light stimulus projected at a certain location.
The COMPASS device interacts with the patient by directing infrared, white, blue and green wavelength illumination into the patient's eye and by recording a patient's confirmation that a certain light stimulus has been perceived or not.
Here's an analysis of the acceptance criteria and the supporting study for the CenterVue COMPASS device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The FDA clearance letter (K150320) primarily focuses on establishing "substantial equivalence" to predicate devices, rather than explicit numerical acceptance criteria for clinical performance that might be found in a performance goal document for a novel device. However, the clinical study serves to demonstrate this equivalence. The key performance comparison is between the CenterVue COMPASS and the Humphrey HFA-II.
| Acceptance Criteria (Implied for Substantial Equivalence to HFA-II) | Reported Device Performance (CenterVue COMPASS) |
|---|---|
| Equivalence in retinal threshold sensitivity measurements for both normal and pathological subjects compared to the Humphrey HFA-II. | Mean differences in thresholds between COMPASS and HFA-II in both subject groups (normal and pathological) were found to be equivalent to those reported for the Humphrey HFA between SITA Standard and full threshold. |
| No significant adverse events during clinical testing. | No adverse event was reported during the study. |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size:
- 200 normal subjects
- 120 subjects with pathology affecting the visual field (specifically glaucoma)
- Total: 320 subjects
- Data Provenance: The document does not explicitly state the country of origin. It indicates the manufacturer is in Padova, Italy, and the study was conducted to support FDA clearance in the USA, suggesting the study likely occurred in conjunction with the manufacturer's operations or clinical sites. The study is presented as prospective clinical testing ("Measurements have been obtained...").
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts
The document does not specify the number of experts or their qualifications for establishing the "ground truth" for the test set (i.e., whether subjects were truly "normal" or had "glaucoma"). It only states that subjects were categorized as "normal" or with "pathology affecting the visual field (in particular glaucoma)." This implies a clinical diagnosis was used, but the specific process or number of experts for this diagnosis is not detailed.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method for the test set in terms of expert review or consensus. The study compares the performance of the COMPASS directly to the predicate device (Humphrey HFA-II) on the same subjects, rather than assessing the COMPASS's ability to classify against a pre-established ground truth determined by multiple experts.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
No, an MRMC comparative effectiveness study was not done. This device is primarily a diagnostic instrument for measuring retinal sensitivity and imaging, not an AI-assisted diagnostic aid for interpretation by human readers. The clinical study compares the device's measurements to another device, not human performance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, the clinical study presents data on the standalone performance of the CenterVue COMPASS device in measuring retinal threshold sensitivity. It directly compares the measurements obtained by the COMPASS to those obtained by the Humphrey HFA-II. The device operates as a standalone unit for acquiring images and measuring retinal sensitivity.
7. The Type of Ground Truth Used
The "ground truth" in this context is the measurement of retinal threshold sensitivity as determined by the accepted standard, the Humphrey HFA-II. The study aims to demonstrate that the COMPASS's measurements are "equivalent" to those of the HFA-II, specifically that the mean differences in thresholds are comparable to known differences within the HFA-II platform (SITA Standard vs. full threshold). The classification of subjects as "normal" or with "glaucoma" would have been based on clinical diagnosis, implicitly serving as a form of "expert consensus" or "clinical diagnosis" ground truth for subject selection, but not for the specific performance metric being evaluated (threshold sensitivity differences).
8. The Sample Size for the Training Set
The document describes a "reference database" that was developed to serve as a quantitative tool for comparison of retinal sensitivity to known normal subjects.
- Reference Database Sample Size: 200 eyes of 200 normal subjects.
- The age range of this population was 20 - 86 years (50.6 ± 15.2).
9. How the Ground Truth for the Training Set was Established
The ground truth for the "training set" (referred to as the "reference database" in the document) was established by obtaining threshold sensitivity data from 200 subjects confirmed to be "normal." The specific criteria or expert qualifications for determining "normalcy" are not detailed in this summary, but it implies a clinical assessment of individuals free from visual field pathology. The perimetric settings used to gather this data are listed (24-2 grid, 4-2 strategy, Goldmann III stimulus, etc.).
§ 886.1570 Ophthalmoscope.
(a)
Identification. An ophthalmoscope is an AC-powered or battery-powered device containing illumination and viewing optics intended to examine the media (cornea, aqueous, lens, and vitreous) and the retina of the eye.(b)
Classification. Class II (special controls). The device, when it is an AC-powered opthalmoscope, a battery-powered opthalmoscope, or a hand-held ophthalmoscope replacement battery, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 886.9.