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The EM-4000 Specular Microscope is a non-contact ophthalmic microscope, optical pachymeter, and camera intended for examination of the corneal endothelium and for measurement of the thickness of the cornea.

The Tomey EM-4000 Specular Microscope is a non-contact ophthalmic microscope and camera intended for corneal endothelium imaging. Its operating principle is based on the Specular optical principle. This device is used for imaging the corneal endothelium. The EM-4000 analyzes and displays data such as cell number, cell density, coefficient of variation and percent hexagonality. When photographing the corneal endothelium, the equipment performs the alignment and automatically focuses by capturing the reflected light from the patient's eye with the CCD camera. Infrared LEDs are used as the light source for the alignment. Operation with the iovstick also makes it possible to focus manually. The green LED light radiates to the cornea, and the endothelium image is captured with the CCD camera by the reflected light from the cornea. The endothelium images are stored in internal memory.

Furthermore, the EM-4000 is able to measure the central corneal thickness. The corneal endothelium is photographed first followed by measuring the central corneal thickness. The infrared LED light for measurement of corneal thickness radiates to the cornea through the objective lens for photographing the cornea, and the central corneal thickness can be calculated by measuring the distance on the optical line sensor between the reflected light from front surface and back surface of cornea.

Here's an analysis of the acceptance criteria and study detailed in the provided document:

The document describes the Tomey EM-4000 Specular Microscope, a non-contact ophthalmic microscope, optical pachymeter, and camera intended for examination of the corneal endothelium and for measurement of the thickness of the cornea. The study aims to demonstrate substantial equivalence to a predicate device, the Konan Medical, Inc. Cellchek XL (K120264).

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are not explicitly stated as numerical thresholds in this document for all parameters beyond pachymetry. Instead, the study aims to show "agreement, accuracy and precision" with the predicate device, demonstrating substantial equivalence. For pachymetry, a specific accuracy is mentioned.

2. Sample Size Used for the Test Set and Data Provenance

• Test Set Sample Size:
  • Agreement portion (specular microscope variables): 67 subjects
  • Agreement portion (Central Corneal Thickness - CCT): 68 subjects
  • Precision portion: 44 subjects
• Data Provenance: The study was a prospective clinical study. The country of origin is not explicitly stated, but the manufacturer is Tomey Corporation from Japan, and the contact person is in Andover, MA, USA, suggesting it could be a multi-site or US-based study, but this is not confirmed.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

The document mentions that the clinical study results for the device measurements using the Core Method of analysis were based upon the use of a "reading center." However, it does not specify the number of experts or their specific qualifications (e.g., "radiologist with 10 years of experience"). This information is missing from the provided text.

4. Adjudication Method for the Test Set

The document does not explicitly state an adjudication method (e.g., 2+1, 3+1). It mentions a "reading center" was used for the "Core Method of analysis." This implies that images were processed and analyzed, likely by trained readers or technicians at this center, to derive the measurements (CD, CV, %HEX). The comparison is then made between the Tomey EM-4000's results and those derived from the predicate device by this reading center. It's not clear if there was a multi-reader consensus process or a single reader approach for the predicate device's "ground truth" derived by the reading center.

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 study is comparing a new device (Tomey EM-4000) to a predicate device (Konan CellChek XL) to demonstrate substantial equivalence based on their direct measurements of corneal parameters. It is not an AI-assisted human reader study; rather, it is a direct device-to-device comparison. Therefore, there's no reported effect size on how human readers improve with AI assistance.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done

The study primarily evaluates the standalone performance of the Tomey EM-4000 as a diagnostic device by comparing its measurements to those obtained from a predicate device. Both devices are instruments that perform measurements directly. The document states, "The EM-4000 analyzes and displays data such as cell number, cell density, coefficient of variation and percent hexagonality." This implies autonomous algorithmic processing of the captured images without continuous human intervention during the measurement process, although human setup/operation is expected. The "Core Method of analysis" mentioned for the reading center likely refers to the standard analytical algorithms used for both devices' outputs. So, yes, it's essentially a standalone device performance comparison.

7. The Type of Ground Truth Used

The "ground truth" in this study is the measurements obtained from the predicate device, the Konan CellChek XL. The objective is to demonstrate that the Tomey EM-4000 produces measurements that are in agreement with and precise relative to the established predicate device, thus establishing substantial equivalence. It is not pathology, outcomes data, or an independent expert consensus on the true biological value, but rather a comparative truth against a legally marketed device.

8. The Sample Size for the Training Set

The document does not provide information on a training set for the EM-4000. This is typical for a device validation study where the algorithm is presumably already developed and "trained" (if machine learning is involved) prior to clinical evaluation. The clinical study described here functions as a validation/test set to demonstrate comparative performance.

9. How the Ground Truth for the Training Set Was Established

As no training set information is provided, there is no information on how its ground truth was established.

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