(260 days)
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.
| Acceptance Criteria | Reported Device Performance (Tomey EM-4000 vs. Konan Cellchek XL) |
|---|---|
| Pachymetry Accuracy (non-clinical) | ± 10 microns (Confirmed in non-clinical performance summary) |
| Endothelial Cell Density (CD) Agreement | Mean difference for CD: -6.49% (SD 5.648%). 95% LOA: (-413.6, 74.2). Correlation (R): 0.9634. |
| Coefficient of Variation (CV) Agreement | Mean difference for CV: 1.65% (SD 11.304%). Correlation (R): 0.6226. |
| Percent Hexagonality (HEX) Agreement | Mean difference for % HEX: 0.70% (SD 15.091%). Correlation (R): 0.5549. |
| Central Corneal Thickness (CCT) Agreement | Mean difference for CCT: -3.11% (SD 3.995%). Correlation (R): 0.8561. |
| Precision (Repeatability & Reproducibility) | For all variables (CD, CV, HEX, CCT), the Tomey EM-4000 showed slightly less variability compared to the Konan Cellchek XL (e.g., lower Repeatability and Reproducibility SDs, and Repeatability/Reproducibility Ratios |
§ 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.