Clinical testing of intraocular pressure . Self testing of intraocular pressure. Home monitoring of intraocular pressure. Screening studies, and outreach clinics. For Glaucoma, Ocular hypertensive, and general population groups.

Device Description

The phosphene tonometer is a pressure measuring device which consists of three ABS plastic components which are moulded, and a stainless 312 metal spring. These fit together and comprise the body of the instrument, a probe with the spring within and a fiduciary, with reset potential.

AI/ML Overview

The FPT/Fresco Phosphene Tonometer is a pressure measuring device intended for measuring intraocular pressure in clinical and home test use, allowing for self-testing.

Here's an analysis of its acceptance criteria and the supporting study:

1. Acceptance Criteria and Reported Device Performance

Acceptance Criteria (Implicit)	Reported Device Performance
Accuracy: Measurements generally within ±3 mm Hg of Goldmann tonometry in general population.	Clinically, 90% of measurements with the device were within ±3 mm Hg of Goldmann tonometry measurements, when measured by a clinician, or in self-testing of non-diagnostically specific patients.
Accuracy: Measurements generally within ±3 mm Hg of Goldmann tonometry in glaucoma subgroups.	Glaucoma sub-groups yielded 82% within ±3 mm Hg of Goldmann tonometry.
Reproducibility/Precision: Low variation in home self-testing.	Home self-testing for a ten-day period was undertaken in a group of controlled glaucoma patients as well as non-glaucoma cases. Over 2000 measurements were obtained. For two days, measurements were taken every hour. For the remaining eight days, pressure was measured 6 times a day. The standard deviation for readings taken 6 times daily yielded 0.7 mm Hg for 500 weekly readings. This indicates good precision and reproducibility in a real-world home setting.
Stability/Repeatability: Consistent readings over short time intervals.	Successive measurements with the phosphene tonometer yielded no statistically significant difference in repeat testing at 1, 3, 5, 8, 10, and 15 minutes.
Safety: No adverse effects.	There were no adverse effects evident in any of the studies that were evaluated.
Addressing specific patient populations (e.g., advanced visual field loss).	In cases of advanced visual field loss [greater than 14dB on central 24-2 Humphrey], the phosphene tonometer yielded higher readings than Goldmann tonometry [mean difference of 7 mm Hg.]. In these cases, a calibration correction is necessary for home monitoring, which compensates for the individual difference on a case-by-case basis. This demonstrates an understanding of the device's limitations and a proposed solution.

2. Sample Size Used for the Test Set and Data Provenance

The provided information does not explicitly state a single "test set" and its exact sample size or detailed provenance (country of origin, retrospective/prospective). However, the information can be inferred from the study results:

Clinically 90% accuracy: "non-diagnostically specific patients" - no specific sample size given for this group.
Glaucoma subgroup 82% accuracy: Again, no specific sample size provided for this subgroup.
Home self-testing: "a group of controlled glaucoma patients as well as non-glaucoma cases." Over 2000 measurements were obtained over a ten-day period (500 weekly readings mentioned for standard deviation). This implies a significant number of individuals participated to generate 2000+ measurements.
The data would likely be prospective given the nature of tonometer comparisons and home monitoring. The country of origin is not specified, but the applicant's address is in Canada.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications

The document does not explicitly state the number of experts used to establish ground truth or their specific qualifications (e.g., "radiologist with 10 years of experience").

The ground truth reference in the accuracy studies is Goldmann tonometry measurements, performed by a clinician. This implies that qualified medical professionals (likely ophthalmologists or trained technicians) performed the Goldmann tonometry, which serves as the gold standard.

4. Adjudication Method

The document does not describe any specific adjudication method (e.g., 2+1, 3+1) for the test set.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

The document does not describe an MRMC comparative effectiveness study comparing human readers with and without AI assistance. The device is a tonometer, not an AI-assisted diagnostic tool for image interpretation. It measures pressure and relies on a subjective response (perception of a phosphene), but does not involve AI for interpretation or decision support for human readers.

6. Standalone Performance

Yes, a standalone performance was done, in the sense that the device's performance was compared directly to a reference standard (Goldmann tonometry). The FPT/Fresco Phosphene Tonometer is itself a standalone device that provides a measurement; it is not presented as an AI algorithm augmenting human performance.

The accuracy studies (90% and 82% within ±3 mm Hg of Goldmann) directly assess the device's standalone ability to measure intraocular pressure relative to the established standard.

7. Type of Ground Truth Used

The primary ground truth used is measurements from Goldmann tonometry. Goldmann tonometry is the widely accepted clinical gold standard for measuring intraocular pressure.

8. Sample Size for the Training Set

The document does not mention a "training set" in the context of an algorithm or AI model development. The FPT/Fresco Phosphene Tonometer is a mechanical device, not a software algorithm that requires a training set. The various study results reflect validation of the device's performance against a known standard.

9. How the Ground Truth for the Training Set Was Established

Since there is no mention of a "training set" or an AI algorithm, the ground truth establishment for a training set is not applicable to this device. The validation involves comparing the device's readings to directly measured Goldmann tonometry.

Summary

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MAR 2 0 2000

K991840

Bernard B Fresco 40 Saint Clair Avenue East #303 Toronto, Ontario M4T 1M9 Canada

Fax: (416) 922-2020 Phone: (416) 922-2020 Contact Person: Bernard B Fresco

Email: fppt@aol.com

SUMMARY

Trade Name: FPT/Fresco Phosphene Tonometer

Common Name: Pressure Phosphene Tonometer/Eyelid Tonometer

Classification Name: Tonometer for clinical and home self-testing, as per 21CFR § 886.1930

Description

Intended Use

Tonometer for measuring intraocular pressure in clinical and home test use. Allows for self-testing, as it is applied to the eyelid, and has a subjective end point.

Technological Characteristics

The pressure phosphene tonometer differs from the Goldmann tonometer in that it is utilised on a closed eyelid instead of the cornea, and it requires a subjective response [perception of a phosphene]. It has no power source requirements.

Study Results

1. Clinically 90% of measurements with the device were within + and -3 mm Hg. Of Goldmann tonometry measurements, when measured by a clinician, or in self-testing of non-diagnostically specific patients.

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7991840

1. Glaucoma sub groups yielded 82% within + and 3 mm Hg. of Goldmann tonometry.
1. Home self-testing for a ten day period was undertaken in a group of controlled glaucoma patients as well as non-glaucoma cases. Over 2000 measurements were obtained. For two days measurements were taken every hour. For the remaining eight days pressure was measured 6 times a day. The standard deviation for readings taken 6 times daily yielded 0.7 mm Hg for 500 weekly readings.
1. In cases of advanced visual field loss [greater than 14dB on central 24-2 Humphrey], the phosphene tonometer yielded higher readings than Goldmann tonometry [mean difference of 7 mm Hg.]. In these cases a calibration correction is necessary for home monitoring, which compensates for the individual difference on a case by case basis.
1. Successive measurements with the phosphene tonometer vielded no statistically significant difference in repeat testing at 1, 3, 5, 8, 10 and 15 minutes.
1. There were no adverse effects evident in any of the studies that were evaluated.

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Image /page/2/Picture/1 description: The image shows the logo for the Department of Health & Human Services - USA. The logo is circular, with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. In the center of the circle is an emblem featuring a stylized eagle with three lines representing its wings and a wavy line representing its body.

Public Health Service

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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Dr. Bernard B. Fresco 40 Saint Clair Avenue East #303 Toronto, Ontario M4T 1M9 Canada

Re: K991840 Trade Name: FPT/Fresco Phosphene Tonometer Regulatory Class: II Regulation: 886.1930 Product Code: 86 HKY Dated: May 25, 1999 Received: May 28, 1999

Dear Dr. Fresco:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic (QS) inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations .

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Page 2- Dr. Bernard B. Fresco

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for questions on. the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

A. Ralph Rosenthal

A. Ralph Rosenthal, M.D. Director Division of Ophthalmic Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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510(k) NUMBER (IF KNOWN)

K991840

DEVICE NAME

Fresco Phosphene Tonometer and or Phosphene Tonometer and or FPT and or Eyelid Tonometer

INDICATIONS FOR USE

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use(Per 21 CFR 801.109)	OR Over-The-Counter-Use ✓(Optional Format 1-2-96)

Bruce Drum

(Division Sign-Off)

Division of Ophthalmic Devices

510(k) Number	K991840
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Regulation Number and Section

§ 886.1930 Tonometer and accessories.

(a)
Identification. A tonometer and accessories is a manual device intended to measure intraocular pressure by applying a known force on the globe of the eye and measuring the amount of indentation produced (Schiotz type) or to measure intraocular tension by applanation (applying a small flat disk to the cornea). Accessories for the device may include a tonometer calibrator or a tonograph recording system. The device is intended for use in the diagnosis of glaucoma.(b)
Classification. Class II.