(166 days)
This device will be used in the same manner as all ophthalmic diagnostic devices used to obtain ocular measurements (for axial length, anterior chamber depth and corneal radius), and perform calculations to allow physicians to determine appropriate IOL power and type for implantation.
The IOLMaster is a non-invasive, non-contact system for measuring the parameters of the human eye required to determine the appropriate power of IOL for implantation, (axial eye length, anterior chamber depth, and corneal radius), and for calculating the optimal power of IOL.
Axial eye length is measured using the principle of partial coherence interferometry (also referred to as laser Doppler interferometry), with a Michelson interferometer.
Corneal radius is measured using traditional keratometery principles. whereby light from LEDs is projected on the cornea of the eve, and after image capturing of the reflected marks and image processing provides the measurement.
Anterior chamber depth is measured by slit lamp illumination. The slit light is scattered by the cornea and the eye lens, generating an image of the cornea and the lens. The image is captured by a CCD-camera. Image processing and edge detection algorithms allow for calculation of the distance between the anterior surface of cornea and lens ( == anterior chamber depth).
These three measurements provide the physician with the data required to calculate the power of IOL to use for a patient. The physician can then choose from one of up to five internationally accepted formulas, built into the IOLMaster, to perform the calculation. The IOL power is then calculated according to the IOL type.
Users can also enter information regarding the different IOL types into the IOLMaster database, which can then be used to suggest the optimal IOL. This calculation and selection process is already performed by ultrasound and other diagnostic devices. However, the choice of formula and final determination of the appropriate IOL is at the physicians' discretion.
Here's an analysis of the provided 510(k) summary regarding the IOLMaster device, focusing on its acceptance criteria and the study used to validate its performance:
1. Table of Acceptance Criteria and Reported Device Performance
The 510(k) summary does not explicitly state "acceptance criteria" in a quantitative manner. Instead, it presents the device's performance as the deviation from established comparative devices. This deviation serves as the functional equivalent of performance criteria, where smaller deviations indicate better agreement and thus, acceptable performance relative to the established gold standards.
| Measurement Parameter | Acceptance Criteria (Proxy: Deviation from Comparative Devices) | Reported Device Performance (IOLMaster) |
|---|---|---|
| Axial Eye Length | (Implicitly: small deviation from GBS) | -0.03 ± 0.21 mm (vs. GBS) |
| Corneal Radii | (Implicitly: small deviation from ALCON) | -0.01 ± 0.06 mm (vs. ALCON) |
| Anterior Chamber Depth | (Implicitly: small deviation from GBS) | 0.12 ± 0.18 mm (vs. GBS) |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size:
- The second stage testing involved 155 human eyes.
- Prior to this, a "first stage testing" involved 678 human eyes. It's important to note that the detailed performance metrics are given for the 155 human eyes in the second stage testing, which seems to be the primary dataset for the reported deviations.
- Data Provenance: The study was conducted at the University Eye Clinic, Wuerzburg, Germany in February 1999. The data is prospective, as it describes the measurement of human eyes with the IOLMaster prototype and comparative devices.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
The document does not specify the number of experts used to establish the ground truth. The "ground truth" was established by measurements from existing, cleared devices (Grieshaber Biometry System, AL-1000 A-scan device, ALCON Ocuscan keratometer). These are considered established methods, and the expertise would lie in operating these devices and interpreting their results. There's no mention of a separate expert panel adjudicating the measurements from these objective devices.
4. Adjudication Method for the Test Set
There is no mention of an adjudication method in the traditional sense (e.g., 2+1, 3+1). The "ground truth" was established by direct measurements from the comparative devices, not by human consensus or review of IOLMaster results. The study directly compared IOLMaster measurements to these reference device measurements.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted. This study focuses on the agreement between the IOLMaster device and existing measurement devices, not on the improvement of human readers with or without AI assistance. The IOLMaster is a diagnostic measurement device, not an AI-assisted diagnostic aid for human interpretation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, this was a standalone performance study. The IOLMaster directly generates measurements (axial eye length, corneal radii, anterior chamber depth) using its internal algorithms, and these measurements were directly compared against the measurements obtained from the predicate devices. The performance metrics (deviations) are for the device itself. While physicians use the device, the measurements themselves are output by the algorithm.
7. The Type of Ground Truth Used
The ground truth used was measurements obtained from established, high-accuracy comparative devices.
- For Axial Eye Length and Anterior Chamber Depth, the Grieshaber Biometry System ("GBS"), a high-accuracy ultrasound biometry unit in immersion technique, was used as the ground truth. The TOMEY "AL-1000" A-scan device was also mentioned as a comparative device in the broader first-stage testing.
- For Corneal Radii, the ALCON "Ocuscan" keratometer was used as the ground truth.
8. The Sample Size for the Training Set
The document does not explicitly state a sample size for a training set. The study describes validation and verification testing of a "prototype" with specific performance data. While the device utilizes image processing and algorithms, there's no mention of a separate set of data specifically used for machine learning model training. The development process likely involved an internal testing and calibration process, but this is not detailed as a "training set" in the submission. The "first stage testing of 678 human eyes" could be considered part of an early development or internal validation, but it's not explicitly called a training set.
9. How the Ground Truth for the Training Set Was Established
Since a "training set" is not explicitly described, the method for establishing its ground truth is also not detailed. If the 678 human eyes in the first stage testing served as an internal development/training set, it would likely have used similar comparative devices as the reported validation study.
§ 886.1850 AC-powered slitlamp biomicroscope.
(a)
Identification. An AC-powered slitlamp biomicroscope is an AC-powered device that is a microscope intended for use in eye examination that projects into a patient's eye through a control diaphragm a thin, intense beam of light.(b)
Classification. Class II (special controls). The device, when it is intended only for the visual examination of the anterior segment of the eye, is classified as Group 1 per FDA-recognized consensus standard ANSI Z80.36, does not provide any quantitative output, and is not intended for screening or automated diagnostic indications, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 886.9.