(254 days)
The OPTICAL BIOMETER AL-Scan is a medical device that optically measures eye components such as:
- axial length;
- corneal thickness;
- anterior chamber depth;
- corneal curvature radii;
- corneal cylinder axis;
- white-to-white distance; and
- pupil diameter.
Axial length and corneal thickness can also be measured using ultrasound.
The OPTICAL BIOMETER AL-Scan also performs calculations to assist physicians in determining the power of the intraocular lens for implantation.
Diagnostic ultrasound imaging or fluid flow analysis of the human body as follows: Ophthalmic (A-mode)
The OPTICAL BIOMETER AL-Scan ("AL-Scan") measures ocular measurements including: axial length, corneal thickness, anterior chamber depth, corneal curvature radii, corneal cylinder axis, white-to-white distance, and pupil diameter. It measures these necessary values successively through a non-contact optical measurement method. The AL-Scan measures as a single unit the values necessary to calculate the power of an IOL for cataract surgery.
Two optional ultrasonic probes (A-scan Probe and Pachymetry Probe) are available for use in the event the optical measurement is unsuccessful. The A-scan probe scans the axial length, anterior chamber depth, lens thickness and the pachymetry probe scans the corneal thickness. Both probes utilize an ultrasonic measurement function by touching the probe to the cornea.
The AL-Scan also has the function to calculate the power of an IOL using measured values such as axial length.
The Nidek Optical Biometer AL-Scan (K133132) was tested for agreement with predicate devices (LenStar LS 900 and PacScan 300A for ultrasound measurements) and its own precision (repeatability and reproducibility).
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria for each measurement were implicitly defined by demonstrating agreement with the predicate devices within calculated 95% Confidence Intervals (CI) for the mean difference and 95% Limits of Agreement (LoA), as well as by achieving acceptable reproducibility and repeatability (measured by Standard Deviation (SD) and Coefficient of Variation (CV)).
Here's a summary of the reported device performance, highlighting key metrics, particularly for the "All Eye Populations Combined" data from Tables 1, 3, and 5. The agreement values represent the difference between the AL-Scan and the predicate device. The precision values (reproducibility and repeatability) are for the AL-Scan itself.
| Measure | Acceptance Criteria (Implicitly from Predicate Agreement/Precision) | AL-Scan Performance (Agreement with LenStar LS 900/PacScan 300A) | AL-Scan Performance (Precision - Reproducibility & Repeatability) |
|---|---|---|---|
| Axial Length (mm) | Small mean difference and narrow LoA with predicates; low SD/CV. | LenStar LS 900: Mean Diff: -0.007 ± 0.029, 95% CI: [-0.014; -0.001], 95% LoA: [-0.063, 0.049] | |
| PacScan 300A: Mean Diff: 0.034 ± 0.241, 95% CI: [-0.019; 0.088], 95% LoA: [-0.439, 0.507] | Reproducibility: SD: 0.034, %CV: 0.1% | ||
| Repeatability: SD: 0.034, %CV: 0.1% | |||
| Keratometry SE (mm) | Small mean difference and narrow LoA with predicates; low SD/CV. | LenStar LS 900: Mean Diff: -0.015 ± 0.043, 95% CI: [-0.025; -0.005], 95% LoA: [-0.100, 0.070] | Reproducibility: SD: 0.060, %CV: 0.8% |
| Repeatability: SD: 0.060, %CV: 0.8% | |||
| Corneal Cylinder Axis (°) | Small mean difference and narrow LoA with predicates; low SD/CV. | **LenStar LS 900 (Cylinder |
§ 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.