(908 days)
The Pediatric Vision Scanner is intended for the automated detection of misalignment of the visual axes using polarized light. It is indicated for the screening of amblyopia and microstrabismus associated with amblyopia in children age 2 to 8 undergoing evaluation in a professional eye care setting and who are responsive to taking direction and who can pay attention for at least 5 seconds.
The Pediatric Vision Scanner (PVS) is a non-invasive, optical instrument intended to be used for ophthalmic diagnostic purposes. The device integrates all hardware components within the plastic enclosure, including the image acquisition optics, the system computer, and visual display. The PVS is to be held with both hands and level to the ground, with the aperture aimed toward the child. The operator positions the PVS in dim light. Prior to each measurement, a background measurement is obtained to minimize signal interference. Rangefinders (laser diode, 650 nm wavelength) allow the proper positioning of the device (~ 0.5 meters) during background measurement and measurement. After the background is obtained, the operator instructs the patient to open their eyes, peer into the lens (with both eyes), and fixate on a target light (red Light-Emitting Diode (LED)) source (in the shape of a "smiley face"). The operator performs the measurement; a spot of near-infrared (laser diode, 830 nm wavelength), polarized light rotates circularly around the fixation target. Based on the polarization characteristics of the received light, the device uses an algorithm to determine whether or not this light is incident on the nerve fibers emanating from the fovea, the central retinal area for normal visual fixation, of each eye. Based upon this analysis and determination, the following output information is presented to the operator: LED outputs (based on binocularity values), "Tries": total number of scans (performed in two sets of 5, a maximum of 10), "Yield": ratio of number of scans that produced a signal to number of tries, "Binoc" / "binocularity": the ratio of scans resulting in bilateral, simultaneous fixation to number of tries. The device has an optical portion and integrated software analysis to administer, interpret, and convey the results of a scan. The optical portion of the device may be divided into two major pathways: Illumination pathway and Viewing pathway.
Here's a breakdown of the acceptance criteria and the study proving the device meets those criteria, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Clinical Performance: | |
| Sensitivity ≥ 80% | 88.81% (95% CI: 82.47 – 93.47%) |
| Specificity ≥ 82% | 91.74% (95% CI: 84.90 – 96.16%) |
| Non-clinical Performance (Bench - Lower Limit of Detection): | |
| "Pass" results (≥60% binocularity) when prisms inducing deviation below lower detection limit are used. | All devices showed 100% BIN for lower powered prisms, indicating a "Pass." One device showed 60-100% BIN at the detection limit (average 92%), still a "Pass." (Detection limit is between b(4) prism diopters) |
| "Refer" results ( |
§ 886.1342 Strabismus detection device.
(a)
Identification. A strabismus detection device is a prescription device designed to simultaneously illuminate both eyes with polarized light for automated detection of strabismus by analyzing foveal birefringence properties.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Clinical performance testing must demonstrate the device performs as intended under anticipated conditions of use. Testing must be conducted in a representative patient population and clinical setting for the indicated use. Demonstration of clinical performance must include assessment of sensitivity and specificity compared to a clearly defined reference standard (e.g., comprehensive ophthalmological examination comprises age-appropriate visual acuity testing, examination of the external ocular adnexae and orbit, anterior segment evaluation, extraocular motility evaluation, assessment of stereopsis, cycloplegic refraction, and dilated fundus examination).
(2) Non-clinical performance testing must demonstrate the device performs as intended under anticipated conditions of use. The following technical characteristics must be evaluated:
(i) Verification of lowest detectable amount of deviation; and
(ii) Validation of the accuracy and precision at the lowest detectable amount of deviation.
(3) Software verification, validation, and hazard analysis must be performed.
(4) Optical radiation safety testing must demonstrate the device is safe per the directions for use.
(5) Performance testing must demonstrate the electromagnetic compatibility of the device.
(6) Performance testing must demonstrate the electrical safety of the device.
(7) Labeling must include the following:
(i) Summaries of non-clinical and clinical performance testing;
(ii) Instructions on how to correctly use and maintain the device;
(iii) Instructions and explanation of all user-interface components; and
(iv) Information related to electromagnetic compatibility and optical radiation classification.