(268 days)
The Nidek Specular Microscope CEM-530 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 Nidek Specular Microscope CEM-530 provides non-contact, high magnification image capture of the endothelium enabling observation of the size and shape of cells. Information such as the number of endothelial cells, cell density, and cell area is analyzed through the captured images. The captured images and analysis results of the endothelium are used in intraocular or corneal surgery, postoperative follow-up, and corneal observation such as for endothelial disorders or the corneal state of patients who wear extended-wear contact lenses. Observation is possible in the central area (visual angle: 5°) and peripheral area (visual angle: 27°) using a periphery capture function as well as in the center of the captured images and analysis results can be printed on the built-in printer or optional video printer, or output to an external device over LAN connection. In addition to the specular microscopy, the corneal thickness can be optically measured in a non-contact method. The CEM-530 has auto-tracking and auto-shooting functions. Results can be printed using the the built-in thermal printer or captured images can be transferred to a filing system via LAN connection.
The Nidek Specular Microscope CEM-530 performed a clinical study to demonstrate substantial equivalence to the predicate device Konan Medical, Inc. Cellchek Plus (K120264).
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria were not explicitly stated as numerical thresholds in the provided text. Instead, the study aimed to demonstrate "agreement, accuracy, and precision" between the Nidek CEM-530 and the predicate device, with results being "acceptable" and "substantially equivalent." The key metrics evaluated were:
| Variable | Performance of Nidek CEM-530 (Mean) | Performance of Konan CELLCHEK XL (PLUS) (Mean) | Mean Difference (CEM-530 - Predicate) | Mean Difference as a % of Predicate Reading | Correlation (R²) vs. Predicate | 95% Limits of Agreement (LOA) | Repeatability Ratio (CEM-530/Predicate) | Reproducibility Ratio (CEM-530/Predicate) |
|---|---|---|---|---|---|---|---|---|
| Endothelial Cell Density (CD) | 2482.6 cells/mm² | 2553.1 cells/mm² | -70.5 cells/mm² | -0.42% | 0.9654 | (-406.3, 265.2) | 1.2102 | 1.1887 |
| Coefficient of Variation Endothelial Cell Area (CV) | 29.9% | 31.2% | -1.3% | 0.77% | -0.0088 | (-18.5, 15.9) | 0.8746 | 1.0016 |
| % Hexagonality | 69.0% | 59.3% | 9.7% | 18.19% | 0.2036 | (-7.2, 26.5) | 0.7586 | 0.7466 |
| Central Corneal Thickness (CCT) | 551.5 microns | 565.2 microns | -13.8 microns | -2.38% | 0.8856 | (-53.0, 25.5) | 0.2634 | N/A (Not provided for CCT) |
Summary of Device Performance against Implicit Acceptance Criteria:
- Agreement: The study reported that "Agreement of the measurements with the CEM-530 and the predicate device was found to be acceptable." Bland-Altman plots generally showed LOAs including 0, indicating no overwhelming systematic bias.
- Accuracy: Differences were generally small (3-5% for CD, CV, CCT) except for % Hexagonality (15%). Deming regression plots showed good agreement for CD, CCT, and CV (especially after outlier removal for CV).
- Precision: "Overall, within eye/subject variability was acceptable, and similar for both machines." Repeatability was notably better for Nidek CEM-530 for CCT, and comparable for other endpoints.
- Substantial Equivalence: The overall conclusion was that the Nidek CEM-530 is "substantially equivalent" to the predicate device based on these performance metrics.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Agreement Assessment: 74 eyes
- 24 non-pathologic young eyes (18-28 years of age)
- 25 non-pathologic adult eyes (29-80 years of age)
- 25 pathologic adult eyes (29-80 years of age)
- Sample Size for Precision Assessment: 62 evaluable eyes
- 20 non-pathologic young eyes
- 22 non-pathologic adult eyes
- 20 pathologic adult eyes
- Data Provenance: The study was a prospective clinical study. The country of origin of the data is not explicitly stated, but the sponsor and manufacturer are NIDEK Co., Ltd. in Japan, and the contact person is in Andover, MA, USA. It's common for such studies to be conducted in multiple locations, but this information is not provided.
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 or their qualifications for establishing the ground truth. The "ground truth" for this study was established by comparing the Nidek CEM-530's automatic measurements against the predicate device (Konan Cellchek Plus)'s manual measurements. It is implied that the manual measurements from the predicate device serve as the reference standard.
4. Adjudication Method for the Test Set
The document does not explicitly describe an adjudication method for the test set. The comparison was primarily between the automated measurements of the Nidek CEM-530 and the (presumably expert-performed) manual measurements from the predicate device.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed to assess the improvement of human readers with AI vs. without AI assistance. This study focused on the performance of a new automated device (Nidek CEM-530) compared to an existing predicate device (Konan Cellchek Plus), which primarily involved a comparison of device measurements rather than human reader performance with or without AI assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, a standalone performance study was done. The Nidek Specular Microscope CEM-530 is described as having "auto-tracking and auto-shooting functions" and "automatic image analysis." The clinical study reported on the "agreement, accuracy and precision of the CEM-530 by comparing results across three machines/operators to those obtained with the predicate device," and specifically "evaluates the precision and accuracy of the automatic analyses performed by the CEM-530 compared to manual measurements performed with the predicate device." This indicates that the CEM-530's automatic analysis was tested in a standalone capacity. An additional analysis was performed on 24 images comparing the automated method to a manual method on the same image.
7. Type of Ground Truth Used
The primary "ground truth" used for comparison was the manual measurements performed with the predicate device, the Konan Cellchek Plus. For the additional analysis on 24 images, the "manual method of analysis on the same image" served as the comparison for the automated method.
8. Sample Size for the Training Set
The document does not provide information regarding a separate training set or its sample size. The clinical study was conducted to assess the performance of the already developed CEM-530 device.
9. How the Ground Truth for the Training Set Was Established
Since information about a specific training set or its sample size is not provided, the method for establishing ground truth for a training set is not available in the document.
§ 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.