(194 days)
The ANTERION is a non-contact ophthalmic imaging and analysis device for the eye. It is intended for visualization and measurement of the anterior segment and measurement of the axial length.
The analysis covers:
- · Cornea Thickness
- · Anterior Segment
- o Anterior chamber width, depth, volume and angle parameters
- o Lens Thickness
- · Axial Length
The ANTERION is a diagnostic imaging device for the eye. The technology is based on swept-source optical coherence tomography (SS-OCT) technology. The device itself has two basic component groups:
- ANTERION Hardware (Imager/Base) with integrated forehead/ chin rest: The . hardware includes imaging hardware (e.g., laser, LEDs, optics, detectors, hardware for spatial encoding) as well as a touch screen.
- . ANTERION Software (V.1.2.4) (PC): The ANTERION Software includes the main user interface. The software allows for device control, such as selection of examination(s) and imaging parameter(s). The ANTERION software provides an interface for a Medical Image Management and Processing System.
The ANTERION hardware is separated in three parts: the Base (bottom part), the Imager (top part), and the Head Rest (forehead/chin rest).
For examinations, the patient places his/her head in the forehead/chin rest. The Head Rest is mechanically and electronically connected to the Base and controlled via a joystick. Placed within the stand are a stepper motor with additional mechanical parts and a controller board, allowing the operator to move the motorized chin rest up or down for optimally positioning the patients' eye. An external fixation light is mounted at the forehead rest.
The Base mainly contains the power supply and PC connection of the device. In the Imager, the components for scanning, signal generation, and signal processing are contained.
The operator directly accesses two software modules, which are named AQM (acquisition module) and VWM (viewing module). The AQM allows selecting between examinations. The VWM shows acquired images, parameters, and reports.
The ANTERION device contains two imaging modalities, a scanning optical coherence tomography (OCT) modality and an infrared (IR) camera. The OCT modality allows for cross-sectional imaging and biometry, while the IR camera allows for en-face imaging of a patient's eye.
The ANTERION device provides four separate software applications (Apps) to acquire various imaging and measurements of the anterior segment of the eye: (1) the Imaging App (cleared under K211817), (2) the Cornea App, (3) the Cataract App and (4) the Metrics App. The Cornea App provides tomographic data and measurements paraments for the patient's individual corneal geometry and corneal characteristics. The Cornea App provides tomographic data and parameters, such as corneal curvature and thickness. The Cataract App provides key measurements for the cataract surgery planning, such as corneal thickness, anterior chamber depth and axial length. The Metrics App generates OCT images and scan parameters for the anterior chamber such as anterior chamber angle and volume. The four ANTERION Apps are locked/unlocked independently by a license mechanism for each App. The software implementation of these Apps is realized within the AQM and VWM.
This submission is to seek clearance for the Metrics App, Cataract App and Cornea App.
To function as intended, the ANTERION must be connected to a Medical Image Management and Processing system (MIMPS) with compatible interface. To date, HEYEX 2 / HEYEX PACS is the only available MIMPS with compatible interface.
The provided text describes the acceptance criteria and the study that proves the device meets those criteria for the ANTERION device (K230897).
Here's the breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" in a table format with specific thresholds for each parameter. Instead, it presents extensive "Repeatability and Reproducibility" data (precision analyses) from two clinical studies (B-2018-3 and B-2018-5). The implication is that the demonstrated precision values meet the internal acceptance criteria for the device's performance.
Therefore, the table below will present the reported device performance, which is implicitly what the device "met" to achieve clearance. It's important to note that specific numerical acceptance thresholds are not explicitly defined in the provided text. The reported values are the performance demonstrated by the device in the studies.
Table 1: Reported Device Performance (Repeatability and Reproducibility)
| Parameter (ANTERION App) | Eye Population Category | Repeatability CV% (min-max across tables) | Reproducibility CV% (min-max across tables) |
|---|---|---|---|
| Metrics App | Open Angle Eyes | 4.696% (SSA 750 Nasal) - 35.515% (Lens Vault) | 6.219% (SSA 750 Nasal) - 45.011% (Lens Vault) |
| Metrics App | Narrow Angle Eyes | 0.511% (STS Distance) - 18.363% (AOD 500 Temporal) | 0.662% (STS Distance) - 24.415% (AOD 500 Temporal) |
| Cataract App (Biometry) | Normal Eyes | 0.018% (Axial Length) - 0.270% (Lens Thickness) | 0.027% (Axial Length) - 0.749% (CCT) |
| Metrics App (Biometry) | Normal Eyes | 0.202% (CCT) - 0.742% (AC Volume) | 0.362% (ACD) - 1.978% (AC Volume) |
| Cataract App (Biometry) | Cataract Eyes | 0.081% (Axial Length) - 0.446% (CCT) | 0.081% (Axial Length) - 0.819% (CCT) |
| Metrics App (Biometry) | Cataract Eyes | 0.142% (Lens Thickness) - 0.621% (AC Volume) | 0.208% (Lens Thickness) - 1.171% (AC Volume) |
| Cataract App (Biometry) | Eyes with Corneal Abnormalities | 0.049% (Axial Length) - 0.854% (Thinnest Point Thickness) | 0.067% (Axial Length) - 1.086% (Thinnest Point Thickness) |
| Metrics App (Biometry) | Eyes with Corneal Abnormalities | 0.217% (CCT) - 0.599% (AC Volume) | 0.438% (ACD) - 1.455% (CCT) |
| Cataract App (Biometry) | Post-Keratorefractive Surgery Eyes | 0.018% (Axial Length) - 0.259% (Thinnest Point Thickness) | 0.028% (Axial Length) - 0.966% (CCT) |
| Metrics App (Biometry) | Post-Keratorefractive Surgery Eyes | 0.182% (Lens Thickness) - 0.677% (AC Volume) | 0.275% (ACD) - 1.394% (AC Volume) |
| Cataract App (Biometry) | Eyes without Crystalline Lens | 0.027% (Lens Thickness) - 0.148% (CCT) | 0.111% (Lens Thickness) - 0.634% (CCT) |
| Metrics App (Biometry) | Eyes without Crystalline Lens | 0.223% (CCT) | 0.632% (CCT) |
Note regarding Acceptance Criteria: The document states, "The device met all pre-determined acceptance criteria" under "Non-Clinical Performance Testing". For clinical performance, it states, "Results of the clinical performance testing demonstrate a favorable clinical performance profile that supports a determination of substantial equivalence." This implies that the demonstrated repeatability and reproducibility values, as detailed in the tables, were considered acceptable for the device's intended use. Specific numerical thresholds for each parameter are not provided.
2. Sample Size Used for the Test Set and Data Provenance
The provided text details the sample sizes for the clinical studies which serve as the test sets for the device's performance.
-
Study Protocol B-2018-3:
- Sample Size:
- Group A (open angle): 29 participants completed, data from 25 for precision analyses (225 scans). 27 for agreement analyses.
- Group B (narrow angle): 27 participants completed, data from 27 for precision analyses (234 scans). 26 for agreement analyses.
- Total enrolled: 30 Group A, 28 Group B.
- Data Provenance: Single clinical site in the United States. The study was prospective, observational clinical study.
- Sample Size:
-
Study Protocol B-2018-5:
- Sample Size: 176 participants enrolled, 172 completed.
- Group A (normal anterior segment): 27 participants.
- Group B (cataract): 33 participants.
- Group C (corneal abnormalities): 45 participants (38-43 for specific parameters in precision analysis tables).
- Group D (post-keratorefractive surgery): 29 participants (28-29 for specific parameters).
- Group E (pseudophakic/aphakic eyes): 41 participants (39-40 for specific parameters).
- Scans: Varied per parameter and group, ranging from ~243 to 378 scans for precision analysis.
- Data Provenance: Single clinical site in the United States. The study was prospective, observational clinical study.
- Sample Size: 176 participants enrolled, 172 completed.
3. Number of Experts Used to Establish Ground Truth and Qualifications
The provided text does not explicitly state the number of experts or their qualifications used to establish ground truth for the test set.
It mentions:
- "Manual correction of ANTERION segmentation and manual editing of the scleral spur and angle recess points were performed as needed" for Protocol B-2018-3.
- "Manual correction of ANTERION segmentation was performed by an independent reading center and manual placement of the angle recess points were performed" for Protocol B-2018-5.
While it mentions manual correction and an "independent reading center," it does not specify the number of experts, their specialty (e.g., ophthalmologists, optometrists, or technicians), or their years of experience for establishing this ground truth.
4. Adjudication Method for the Test Set
The document mentions "Manual correction of ANTERION segmentation and manual editing of the scleral spur and angle recess points were performed as needed" and "Manual correction of ANTERION segmentation was performed by an independent reading center and manual placement of the angle recess points were performed."
However, it does not describe a formal adjudication method (e.g., 2+1, 3+1, majority vote, etc.) for resolving disagreements among multiple readers or for establishing the final "ground truth" if multiple experts were involved in these manual corrections. It implies that a single "manual correction" was applied, but the process for achieving a single corrected state from potentially multiple reviewers or iterations is not detailed.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, a standard MRMC comparative effectiveness study was not performed as described for AI assistance.
The studies compared the ANTERION device's measurements not to human readers' performance, but to other devices (CIRRUS HD-OCT 5000 and Pentacam AXL) for accuracy and to itself for precision (repeatability and reproducibility). The ANTERION is an imaging and measurement device, not an AI-assisted diagnostic tool that aids human readers in interpretation. Therefore, a study of how human readers improve with AI vs without AI assistance is not applicable in the context described.
The studies assessed the ANTERION's ability to consistently and accurately measure ophthalmological parameters.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
The performance results presented (Repeatability and Reproducibility) for the ANTERION device represent its standalone performance as a measurement device. The reported CV% values reflect the device's inherent precision in generating these measurements.
While manual corrections of ANTERION segmentation were performed in the studies, this was described as a step in processing the acquired images to enable measurements, rather than human "interpretation" of the algorithm's output for diagnostic purposes in a human-in-the-loop scenario. The repeatability and reproducibility are derived from the measurements produced by the device, sometimes after such manual adjustments. The overall goal was to demonstrate the consistent and accurate measurement capability of the device rather than a diagnosis assistance system.
7. The Type of Ground Truth Used
The ground truth for the clinical performance assessment appears to be based on:
- Comparison to legally marketed devices: The studies performed "agreement analyses" with CIRRUS HD-OCT 5000 and Pentacam AXL, implying these served as reference or comparative ground truth for measurement accuracy. The details of these agreement analyses (e.g., Bland-Altman, Deming regression) are mentioned, but the specific numerical outcomes of these agreement analyses are not provided in the excerpt.
- Manual correction by experts/independent reading center: For measurements derived from image segmentation (e.g., angle parameters, corneal thickness, chamber depth), "manual correction of ANTERION segmentation" and "manual placement of the angle recess points" were performed. This suggests that the ground truth for these segmented features was established by manual review, presumably by qualified personnel, even though their qualifications are not specified.
Therefore, the ground truth is a combination of comparison to established ophthalmic devices and expert manual correction/review of segmented images. It is not pathology or outcomes data.
8. The Sample Size for the Training Set
The provided document describes the clinical studies for device validation/testing. It does not provide information on the sample size used for the training set of the ANTERION's algorithms. As a measurement device rather than an AI diagnostic algorithm in the typical sense, it's possible that its internal algorithms rely on established physical/optical models and calibration, not necessarily a large-scale "training set" of images in the machine learning context. However, if machine learning was used for segmentation, the training set details are not provided.
9. How the Ground Truth for the Training Set Was Established
Since no information is provided about a "training set" or the use of machine learning for its algorithms, there is no information on how the ground truth for any hypothetical training set was established.
§ 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.