(147 days)
The CA, an auxiliary lens adapter, when used in conjunction with RTVue, is indicated for in vivo imaging and measurement of the cornea and other ocular structures of the anterior segment of the eye.
The CA device uses the same Optical Coherence Tomography (OCT) technology that was previously reviewed by FDA in its clearance of premarket notification K062552 for RTVue. The CA adapter gives the user an option to use the RTUve device as previously approved for retina scans, or to use it for cornea and anterior eye scans. Aside from the CA auxiliary attachment, the RTVue is virtually unchanged for the CA use except the CA software module provides for menu selections in the graphical user interface, which are selected by the operator to label corresponding corneal landmarks instead of those of the retina. The system scans a beam into patient's eye and uses a low coherence interferometer to measure the reflectivity of the ocular tissue. The cross-sectional ocular tissue structure is composed of sequence of A-scans. RTVue has a traditional patient and instrument interface like most ophthalmic devices. The device is mounted on a motorized patient table. The patient will rest their head on the forehead and chin rest. The operator uses joystick to align the device to patient's eye. The computer has a graphic user interface for acquiring, analyzing and displaying the acquired image. The RTVue image acquisition speed and image resolution remain the same when used in conjunction with CA.
The provided document describes the Optovue CA (CAM model) device, an auxiliary lens adapter for the RTVue Optical Coherence Tomography (OCT) system, intended for imaging and measurement of the cornea and other anterior segment ocular structures. The document includes a 510(k) summary and related FDA correspondence.
Here's an analysis of the acceptance criteria and the studies that prove the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state formal "acceptance criteria" with numerical thresholds for performance. Instead, it describes performance characteristics and compares them to predicate devices or establishes correlation with other measurement methods.
| Metric / Objective | Acceptance Criteria (Implicit from Study) | Reported Device Performance (RTVue/CA) |
|---|---|---|
| Image Resolution | Comparable to or better than predicate devices. Resolution suitable for anterior segment imaging. | 5.1 ± 0.4 um (axial resolution). Noted as "about 3 times better than the predicate device Visante OCT." |
| Image Quality (Corneal Imaging) | Capable of providing images comparable to or better than predicate devices, with visible anatomic features. | Capable of providing images that "compare well with the Visante OCT." "Anatomic features of the anterior segment of the eye were visible to the physicians that assessed the RTVue/CA images; the same physicians could not identify these features in the Visante OCT images." (Suggests superiority in feature visibility). |
| Cornea Thickness Measurement Correlation | High correlation with established commercial pachymeters. | - Highly correlated with ultrasound pachymetry system (Pearson r = 0.9889) |
- Highly correlated with Orbscan II (Pearson r = 0.9995)
- Highly correlated with Visante OCT (Pearson r = 0.9924 at vertex, r = 0.9939 over central zone). |
| Cornea Thickness Measurement Reproducibility | Low root-mean-square difference for repeat measurements. | 1.2 um root-mean-square for the difference between repeat pachymetry maps. |
| Safety | No change in safety profile compared to the RTVue base device. | The energy level and all safety-related design of the RTVue remain the same. The addition of the CA does not change safety. |
2. Sample Size and Data Provenance
- Non-Clinical (Image Resolution Test): No sample size is specified for the number of devices or scans. The data provenance is not mentioned, but it's likely an in-house lab test given the "Optovue, Inc." signature at the bottom of the page.
- Clinical (Corneal Imaging Comparison & Cornea Thickness Measurement Comparison): No specific sample sizes for patients or images are provided in the document. The studies are described in a factual manner, implying they are retrospective or prospective clinical evaluations, but no details on study design or data provenance (e.g., country of origin) are given.
3. Number and Qualifications of Experts for Ground Truth
- Clinical (Corneal Imaging Comparison): "Physicians that assessed the RTVue/CA images." The number and specific qualifications (e.g., years of experience, specialty beyond "physicians") of these experts are not specified.
- Clinical (Cornea Thickness Measurement Comparison): The "ground truth" for correlation was established using other commercial pachymeters (ultrasound pachymetry, Orbscan II, Visante OCT), which themselves are considered established measurement tools. No explicit "experts" were used to establish the ground truth beyond the inherent calibration and validation of these established devices.
4. Adjudication Method for the Test Set
The document does not describe any adjudication method for the image assessment or measurement comparisons. It only states that physicians assessed the images and that measurements were compared.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study is mentioned. The document describes a comparison of image quality and measurement correlation, but it does not evaluate human reader performance with or without AI assistance, nor does it provide an effect size for human reader improvement.
6. Standalone Performance Study
Yes, the performance tests described (Image Resolution Test, Corneal Imaging Comparison, Cornea Thickness Measurement Comparison) are all evaluating the standalone performance of the RTVue/CA device. There is no mention of a human-in-the-loop component for these specific performance assessments. The device is purely an imaging and measurement tool.
7. Type of Ground Truth Used
- Image Resolution Test: Likely a physical phantom or standardized target with known dimensions.
- Corneal Imaging Comparison: Subjective assessment by physicians comparing images from RTVue/CA against Visante OCT. The "ground truth" here is the visibility of anatomic features as perceived by the physicians.
- Cornea Thickness Measurement Comparison: The "ground truth" was established by comparison with measurements obtained from other commercially available, established pachymeters (ultrasound pachymetry, Orbscan II, Visante OCT). This relies on the established validity of these predicate measurement devices.
8. Sample Size for the Training Set
The document does not mention any training set or machine learning components. The device as described is an imaging and measurement instrument, not an AI/ML-driven diagnostic tool. Therefore, the concept of a "training set" is not applicable based on the provided information.
9. How Ground Truth for Training Set Was Established
As no training set is mentioned or relevant to the device as described, this information is not applicable.
§ 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.