(106 days)
The Keeler Applanation Tonometer and Digital Keeler Applanation Tonometer are indicated for measuring intraocular pressure to aid in the screening and diagnosis of Glaucoma.
The unmodified device is Keeler Applanation Tonometer and Digital Keeler Applanation Tonometer. Both are Goldman type tonometers to measure intraocular pressure to aid in the screening and diagnosis of glaucoma. In applanation tonometry the intraocular pressure (IOP) is calculated from the force required to flatten a constant area of the cornea. Goldmann tonometry is considered to be the gold standard test and is the most widely accepted method in current practice. The Keeler Tonomate is a flattening cone containing biprism that converts the circular image of the flattened cornea to two semicircles that touch and cross at the time of flattening the cornea. The force required to flatten the cornea is converted to millimeters of mercury (mmHg).
The provided text describes a 510(k) submission for a Keeler Disposable Tonomate (also referred to as Keeler Tonomate), an accessory for the Keeler Applanation Tonometer and Digital Keeler Applanation Tonometer. The submission primarily focuses on demonstrating substantial equivalence to previously cleared devices rather than providing a detailed study with specific acceptance criteria and performance metrics for the accessory itself.
Here's an analysis based on the provided text:
Acceptance Criteria and Device Performance
The document does not explicitly state quantitative acceptance criteria or a formal study designed to measure the performance of the Keeler Tonomate against such criteria. Instead, the submission relies on the concept of substantial equivalence to predicate devices. The primary "acceptance criteria" here is that the modified device (with the disposable prism) should not raise new issues regarding the safety and effectiveness of the existing tonometers.
A table of acceptance criteria and reported device performance, as typically seen in a clinical trial or performance study, is not available in this document. The document argues that the technical characteristics of the disposable prism are identical to non-disposable prisms that have been in successful use since the 1950s.
Study Information (or lack thereof)
1. A table of acceptance criteria and the reported device performance:
- Acceptance Criteria: Not explicitly defined in a quantitative manner for the disposable prism. The implicit acceptance criterion is "substantial equivalence" to the predicate non-disposable prisms, meaning no new safety or effectiveness concerns.
- Reported Device Performance: No specific quantitative performance metrics (e.g., accuracy, precision) are reported for the Keeler Tonomate itself in comparison to a defined acceptance criterion. The document states that the "technical characteristics of Phakos Tonoclean and Keeler Tonomate were kept identical to those of the nondisposable prisms."
2. Sample size used for the test set and the data provenance:
- Sample Size: Not applicable/not provided. No specific test set of patients or measurements with the Keeler Tonomate is described.
- Data Provenance: Not applicable/not provided.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. There was no specific test set requiring expert ground truth establishment for this 510(k) submission.
4. Adjudication method for the test set:
- Not applicable. No test set requiring adjudication was performed.
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 MRMC study was conducted. This device is a tonometer prism, not an AI-assisted diagnostic tool.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This device is a manual measurement tool, not an algorithm.
7. The type of ground truth used:
- Not applicable. No direct "ground truth" was established for the performance of the disposable prism through a new study. The argument is based on the long-standing clinical acceptance and identical technical characteristics of the non-disposable predicate prisms.
8. The sample size for the training set:
- Not applicable. The Keeler Tonomate is a physical medical device accessory, not a machine learning model that requires a training set.
9. How the ground truth for the training set was established:
- Not applicable.
Summary of the Study and Rationale:
The document explicitly states: "No clinical investigations were required as the safety and effectiveness in clinical use of the tonometer prism has been well established for the original equipment manufacturer (OEM) version of the prism, which has been sold into the European market by the manufacturer since 2014. In addition, the technical characteristics of Phakos Tonoclean and Keeler Tonomate were kept identical to those of the nondisposable prisms which were in successful use since 1950s."
This indicates that instead of new performance studies, the submission relies on:
- The established safety and effectiveness of a predicate device (the OEM version of the prism in the European market since 2014).
- The historical, successful use of non-disposable prisms with identical technical characteristics since the 1950s.
- Design control activities, risk management, verification/validation for the manufacturing process of the disposable prism (e.g., packaging and sterilization cycle validation), to ensure the addition of the Keeler Tonomate "does not raise new issues on the safety and effectiveness."
Therefore, the "study" demonstrating the device meets "acceptance criteria" here is a substantiation of equivalence argument based on existing data, manufacturing controls, and the identical technical characteristics of the disposable prism compared to its well-established non-disposable counterparts, rather than new clinical trials or performance assessments of the disposable prism itself.
§ 886.1930 Tonometer and accessories.
(a)
Identification. A tonometer and accessories is a manual device intended to measure intraocular pressure by applying a known force on the globe of the eye and measuring the amount of indentation produced (Schiotz type) or to measure intraocular tension by applanation (applying a small flat disk to the cornea). Accessories for the device may include a tonometer calibrator or a tonograph recording system. The device is intended for use in the diagnosis of glaucoma.(b)
Classification. Class II.