Applanation tonometer AT-2

K182491 · Takagi Seiko Co., Ltd. · HKY · Dec 10, 2018 · Ophthalmic

Device Facts

• Record ID: K182491
• Device Name: Applanation tonometer AT-2
• Applicant: Takagi Seiko Co., Ltd.
• Product Code: HKY · Ophthalmic
• Decision Date: Dec 10, 2018
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 886.1930
• Device Class: Class 2

Indications for Use

The Applanation Tonometer AT-2 is intended to measure intraocular pressure for use as an aid in glaucoma screening and diagnosis.

Device Story

Applanation Tonometer AT-2 is a manual, non-electrical medical device used in conjunction with a slit lamp microscope to measure intraocular pressure (IOP). It operates on the Goldmann applanation principle (Imbert-Fick Law), where the force required to flatten a specific area of the cornea is measured. The device consists of a pressurizing force control unit, a measuring prism (PMMA), and a slit lamp mounting interface. In a clinical setting, a physician or technician applies topical anesthesia and fluorescein to the patient's eye, then contacts the cornea with the prism. The operator observes fluorescent semicircles through the slit lamp and adjusts the force knob until the semicircles align. The resulting pressure value is read from a mechanical drum scale. This measurement assists clinicians in glaucoma screening and diagnosis by providing a quantitative assessment of IOP.

Clinical Evidence

Bench testing only. Performance was evaluated in accordance with ISO 8612:2009 (Ophthalmic instruments - Tonometers). No clinical data was required or provided.

Technological Characteristics

Manual contact tonometer; no electrical components. Patient-contacting material: PMMA (measuring prism). Other components: stainless steel, copper alloy, aluminum alloy. Measurement principle: Goldmann applanation. Form factor: slit-lamp mounted with manual dial. Sterilization: non-sterile, reusable prism requires cleaning/disinfection.

Indications for Use

Indicated for patients requiring intraocular pressure measurement as an aid in glaucoma screening and diagnosis. No specific age or gender restrictions; contraindicated for patients where contact with the cornea is not advised.

Regulatory Classification

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.

Predicate Devices

• Haag-Streit AT900 (K981432)

Reference Devices

• Applanation Tonometer AT-1 (K172728)

Submission Summary (Full Text)

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B-TQMS4101Letterhead Rev.1

Image /page/1/Picture/1 description: The image shows the logo for Takagi Seiko Co., LTD. The logo consists of a blue abstract symbol on the left, followed by the company name in a bold, sans-serif font. A horizontal line is placed beneath the company name, emphasizing the brand.

330-2 IWAFUNE, NAKANO-SHI, NAGANO-KEN, 383-8585, JAPAN TEL. [phone] FAX. [phone] URL: http://www.takagi-j.com E-mail: [e-mail]

## K182491

## 510(k) Summary

## 1. SUBMITTER

| Company Name: | Takagi Seiko Co., Ltd. |
|--------------------------|------------------------------------------------------|
| Company Address: | 330-2 Iwafune, Nakano-Shi, Nagano-Ken 383-8585 JAPAN |
| Telephone No: | [phone] |
| Fax No: | [phone] |
| Contact Person: | SHINYA KITAMURA |
| Title of Contact Person: | None |
| Telephone No: | [phone] |
| Fax No: | [phone] |
| Email Address: | [e-mail] |
| Date Prepared: | December 6, 2018 |

## 2. DEVICE

| Name of Device: | Applanation Tonometer AT-2 |
|----------------------|----------------------------|
| Common Name: | Goldmann Tonometer |
| Classification Name: | Tonometer and Accessories |
| Regulation Number: | 21 CFR 886.1930 |
| Regulatory Class: | II |
| Product Code: | HKY |

## 3. PREDICATE DEVICE

| Name of Device: | Haag-Streit AT900 |
|----------------------|---------------------------|
| 510(k) Number: | K981432 |
| Common Name: | Goldmann Tonometer |
| Classification Name: | Tonometer and Accessories |
| Regulation Number: | 21 CFR 886.1930 |
| Regulatory Class: | II |
| Product Code: | HKY |

## 4. REFERENCE DEVICE

| Name of Device: | Applanation Tonometer AT-1 |
|----------------------|----------------------------|
| 510(k) Number: | K172728 |
| Common Name: | Goldmann Tonometer |
| Classification Name: | Tonometer and Accessories |
| Regulation Number: | 21 CFR 886.1930 |

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| Regulatory Class: | II |
|-------------------|-----|
| Product Code: | HKY |

#### 5. DEVICE DESCRIPTION

#### 5.1 Device Identification

The device consists of a pressurizing force control unit, tonometer tip (hereinafter referred to as measuring prism), section connected to a slit lamp microscope, and accessories. The measuring prism requires disinfection. The device includes no electrical elements. The device is set up to a dedicated support on the slit lamp, and used together with a commercially available slit lamp microscope. The pressurizing force control unit of the device incorporates a measurement dial that indicates pressurizing force, including a pressurizing force control knob, and a prism holder to mount the measuring prism. Also, the pressurizing force control unit includes a connector for a calibrator to check the pressurizing force of the device. The product is a manual medical device.

#### 5.2 Principle Operation

#### a) Measurment Method

The Applanation Tonometer AT-2 is based on the physical law (Imbert-Fick Law) that states: the pressure in a sphere having an infinitely thin wall and containing fluid balances with the external force required for applanation of a certain (corneal) surface to a specified region of applanation based on the deformed shape of the cornea.

Specifically, the device measures the intraocular pressure based on the principle of Goldmann applanation tonometry by which the pressure required for applanation of a certain surface is measured. For measurement in a specified region of applanation in the case where the patient cornea has 3-diopter or greater corneal astigmatism, measurements in a specified region of applanation equivalent to a specified region of applanation without corneal astigmatism can be made by mounting with the angle on the angle scale inscribed on the measuring prism in alignment with the red line on the prism holder at the same angle of the amblyopic meridian of corneal astigmatism of the patient.

#### b) Device works

For the applanation Tonometer AT-2, the sterilized measuring prism is mounted on the prism holder of the tonometer, and after drops of topical anesthesia and fluorescein are placed in the eye of the patient, the measuring prism is brought into contact with the cornea. For accurate measurement of the applanation surface, the operator sets the slit lamp equipped with a blue filter to 10× magnification, illuminates the measuring prism with blue light, and observes the two fluorescent green semicircles (made by the two prisms included in the measuring prism). The pressure is adjusted by the pressurizing knob incorporated in the pressuring force control unit until both ends inside the two semicircles correspondence of both ends inside the two semicircles shows that the specified region of applanation is reached. The adjusted

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pressure is indicated by the pressurizing force indicating scale on the measurement drum incorporated in the device. The scale value indicated by the pressurizing force indicating scale on the measurement drum is read and the value multiplied by 10 is given in millimeter mercury (mmHg).

As the patient is seated, his or her intraocular pressure is measured on the slit lamp as part of regular examination within the range of conventional slit lamp examination.

#### 5.3 Signal Processing

Relationship between the positions indicated on the measurement drum, force on the applanation surface, and pressure (Table 4.1.6)

| Position of the | Force | Pressure | |
|------------------|-------|----------|------|
| measurement drum | mN | kPa | mmHg |
| 1 | 9.81 | 1.33 | 10 |
| 2 | 19.62 | 2.66 | 20 |
| 3 | 29.43 | 39.9 | 30 |
| 4 | 39.24 | 53.2 | 40 |
| 5 | 49.05 | 66.5 | 50 |
| 6 | 58.86 | 79.8 | 60 |
| 7 | 68.67 | 93.1 | 70 |
| 8 | 78.48 | 10.64 | 80 |

Table 4.1.6

#### 5.4 Related accessories are as follows:

Calibrator: used to check the pressurizing force of the device

#### 5.5 Device Characteristics

- 1) Patients-contacting material: PMMA.
- 2) The measuring prism is not sterilized when it is shipped and reusable; it must be cleaned and disinfected before the first use and between each use.

#### 5.6 Environment of Use

3.6.1 Areas of application of the device

The Applanation Tonometer AT-2 is intended for use in medical offices, hospitals, and in optometrist and optician offices and clinics.

3.6.2 Ambient conditions

Temperature: +10℃ to +35℃

Air Pressure: 800hPa to 1060hPa

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Relative humidity: 30% to 75%

### 5.7 Method of Operation

In applanation tonometry the intraocular pressure is calculated from the force required to flatten a constant area of the cornea.

The operation principal based on Goldmann applanation method.

### 5.8 Materials of Use

General type of material used

The Applanation Tonometer AT-2 comes into contact with patients' corneal mucosal membrane surface, the material is acrylic resin and the contact time is limited exposure, respectively.

Other component parts of the device are made of general materials (example: stainless Steel,

copper alloy, and aluminum alloy).

#### 5.9 Calibration

Pressure applied to the pressurizing arm is periodically checked by use of the calibrator during factory production/by users.

## 6. INDICATIONS FOR USE

The Applanation Tonometer AT-2 is intended to measure intraocular pressure for use as an aid in glaucoma screening and diagnosis.

## 7. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE

### 7.1 Comparison of AT900 and AT-2

Table 1. Applanation Tonometer AT-2 vs. HAAG-STREIT Applanation Tonometer AT900

| Comparison of Goldmann Tonometer Technical Characteristics<br>Applanation Tonometer AT-1 vs. Haag-Streit AT900 | | |
|----------------------------------------------------------------------------------------------------------------|-------------------------------------------|-------------------------------------------|
| Criteria | Predicate Device<br>Haag-Streit AT900 | New Device<br>Applanation Tonometer AT-2 |
| 510(k) Number | K981432 | K182491 |
| Type | Manual contact Tonometer | Manual contact Tonometer |
| Indication | Intraocular Pressure<br>(IOP) measurement | Intraocular Pressure<br>(IOP) measurement |
| Design | Slit lamp mounted<br>Manual dial | Slit lamp mounted<br>Manual dial |
| Prism Material | PMMA | PMMA |
| Measurement Range | 0 – 80mmHg | 0 – 80mmHg |
| Measurement Method | Applanation | Applanation |

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| Measurement<br>technique | Direct reading of IOP in<br>mmHg (each division on<br>dial of measuring drum is<br>equal to 0.2gf (1.96mN)) | Direct reading of IOP in<br>mmHg (each division on dial<br>of measuring drum is equal to<br>0.2gf (1.96mN)) |
|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------|
| Applanation circle<br>diameter | 3.06mm | 3.06mm |
| Calibration | Maintenance and calibration<br>required | Maintenance and calibration<br>required |
| Intended use | The Applanation Tonometer AT-2 is intended to measure<br>intraocular pressure for use as an aid in glaucoma screening<br>and diagnosis. | |

### 7.2 Technical Specifications

Table 2. Applanation Tonometer AT-2 vs. HAAG-STREIT Applanation Tonometer AT900

| Models<br>Item | Predicate Device<br>Haag-Streit AT900 | New Device<br>Applanation Tonometer AT-2 |
|-----------------------------|-------------------------------------------------------------------------|------------------------------------------|
| Measurement range | 0-80mmHg | |
| One scale unit | 1.96mN | |
| Measurement accuracy | $\pm$ 1.5 % of the nominal value or $\pm$ 0.49 mN, whichever is greater | |
| Repeatability | $\leq$ 0.50mN | |
| Reverse span | 0.49mN | |
| Applanation circle diameter | | 3.06mm $\pm$ 0.02mm |
| Applanation area | | 7.354 mm³ |
| Dimensions (millimeter) | 89(W) × 115(D)<br>× 250(H) | 207.6 (W)x84(D)<br>x201(H) |
| Weight | 0.5kg | 0.81kg |

## 8. PERFORMANCE AND SAFETY

### 6.1 Performance Testing

Performance of the Applanation Tonometer AT-2 was tested in accordance with ISO 8612:2009-Ophtalmic Instrument-Tonometers, Annex A.2.

### 8.2 Biocompatibility

The AT-2 is surface contacting device intended for limited contact with intact corneas. The device is intended for limited contact duration. The material composition and device manufacturing process are the same as those of the AT-1 prism cleared in K172728; therefore, new biocompatibility testing is not needed.

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#### 8.3 Sterilization

The AT-2 is used non-srerile and sterilization is not applicable. AT-2 Prism and the AT-1 prism (K172728) are identical; therefore, new cleaning and disinfection validation is not needed.

#### 8.4 Electrical safety and electromabnetic compatibility (EMC)

Electrical safety and EMC testing is not applicable. AT-2 does not contain electrical components.

#### 8.5 Software

Software verification and validation is not applicable. AT-2 does not include software.

## 9. Conclusion

According to each evaluation result as mentioned above, the Applanation Tonometer AT-2 is substantially equivalent to the predicate device in safety, performance, specifications.

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Image /page/7/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which is a blue square with the letters "FDA" in white. To the right of the blue square is the text "U.S. FOOD & DRUG ADMINISTRATION" in blue.

December 10, 2018

Takagi Seiko Co., Ltd. Shinya Kitamura Official Correspondent 330-2 Nakano-Shi Nagano-Ken 383-8585 Japan

Re: K182491

Trade/Device Name: Applanation tonometer AT-2 Regulation Number: 21 CFR 886.1930 Regulation Name: Tonometer And Accessories Regulatory Class: Class II Product Code: HKY Dated: September 10, 2018 Received: September 11, 2018

Dear Shinya Kitamura:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate 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) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

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Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801): medical device reporting (reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/CombinationProducts/GuidanceRegulatoryInformation/ucm597488.html; good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (http://www.fda.gov/DICE) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely yours,

for Malvina B. Eydelman, M.D. Director Division of Ophthalmic and Ear, Nose and Throat Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure