(303 days)
The Galilei G6 Lens Professional) is designed to take images of the anterior segment of the eye, which includes cornea, iris, pupil, anterior chamber, and crystalline lens. To evaluate:
- · Corneal shape
- · Pachymetry (corneal thickness)
- Position of the cornea relative to iris and lens
- · Anterior and posterior opacity
- · Anterior chamber angle
- · Anterior chamber depth
- · Volume of the anterior chamber
- · White-to-white distance
- · Pupil size
- · Condition and position of implants (e.g. IOL, phakic IOLs, intracorneal rings)
- · Location of cataracts (nuclear, sub capsular and or cortical), using cross slit imaging with densitometry
- · Condition of the lens (opaque crystalline lens)
- · Lens shape
- · Crystalline lens thickness
The Galilei G6 Lens Professional is designed to additionally evaluate:
• Axial length
The Galilei G6 Lens Professional) also performs calculations to assist physicians in determining the power of the intraocular lens for implantation.
The Galilei G6 Lens Professional is (in hardware and software) identical to the Galilei G4 Dual Scheimpflug Analyzer but features an additional biometry module (hardware and software) referred to as "EBR Accessory".
The Galilei G6 Lens Professional consists of the following functional units:
- Measurement Head Container for the cameras, light sources, monitor drivers and electron-● ics. The Placido disk and Dual-Scheimpflug imaging is integrated into the Measurement Head, which performs a 180-degree rotation during data acquisition.
- Main Monitor Display and navigation through the software, selection of functions. ●
- PC box Container of the power supply and the computer. Periphery (Main monitor, mouse ● and keyboard) is connected directly to the computer.
- . Elevation Table - Height-adjustable instrument table with locking wheels.
- EBR Accessory Container of the EBR main printed circuit board as well as the optical and ● mechanical components such as a scanner and a partial coherence interferometer used for biometry measurements. Mounted inside the PC box.
The GALILE! G6 device takes images of the anterior segment of the eye, which includes the cornea, iris, pupil, limbus, anterior chamber and crystalline lens. Topography and anterior segment tomography are calculated from those images.
A pair of slit light images are recorded simultaneously with two cameras placed at opposite sides at an angle of 45°. Due to the Scheimpflug principle, an angled orientation of the camera's sensor allows a sharp focus over the entire image in spite of the 45° recording angle.
The images are then analyzed and anterior cornea, anterior lens and iris surfaces are detected. This information is then used to reconstruct a three-dimensional model of the anterior chamber.
Twenty (20) concentric rings in the Placido are reflected on the anterior surface of the cornea and recorded by a top-view camera in the center of the measurement head. The sizes and shapes of the recorded rings are used to calculate the curvature of the anterior surface of the eye.
Both the Placido and Scheimpflug information are then merged to a single model of the eye.
The EBR Accessory enables the Galilei G6 to take an optical A-scan by means of partial coherence interferometry.
A beam of partial coherence infrared light is directed along the optical axis into the eye. Whenever it passes a transition between layers with different refractive indices (e.g., corneal surfaces, crystalline lens surfaces, retinal surfaces), a portion of the light is reflected back towards the reflected light is compared to a reference beam passing through a light path of adjustable optical length. The length of the reference arm is varied by a scanner.
When the optical lengths of sample arm and reference arm match to within the coherence length of the partial coherence light source, an interference peak is detected and the corresponding layer within the eye is deduced.
Here's a breakdown of the acceptance criteria and study details for the Galilei G6 Lens Professional, based on the provided document:
Acceptance Criteria and Device Performance
The device's performance was primarily compared to the Pentacam® AXL (predicate device) in terms of agreement, repeatability, and reproducibility of various anterior segment geometry and axial intraocular distance measurements. The Acceptance Criteria are implicitly defined by demonstrating substantial equivalence to the predicate device, meaning the G6's measurements should fall within clinically acceptable differences compared to the AXL. The document highlights that minor differences, if any, should not affect safety or effectiveness.
Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state quantitative acceptance criteria as pass/fail thresholds for each metric. Instead, it aims to demonstrate "substantial equivalence" of the Galilei G6 Lens Professional to the Pentacam® AXL. The reported device performance is presented as repeatability and reproducibility values (SD and CV%) and a qualitative assessment of agreement with the predicate.
| Measure | Acceptance Criteria (Implicit for Substantial Equivalence to Pentacam® AXL) | Reported Galilei G6 Performance (normal eyes) | Reported Pentacam® AXL Performance (normal eyes) | Qualitative Performance Assessment (vs. AXL) |
|---|---|---|---|---|
| Agreement | Substantially equivalent (except for WtW where device-specific offsets are common) | Achieves substantial equivalence | N/A (predicate device) | Substantially equivalent |
| AL [mm] | Repeatability/Reproducibility CV values generally comparable to PAXL, translating to refractive differences |
§ 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.