(256 days)
The IOLMaster 700 is intended for biometric measurements and visualization of ocular structures. The measurements and visualization assist in the determination of the appropriate power and type of intraocular lens. The IOLMaster 700 measures:
- · Lens thickness
- · Corneal curvature and thickness
- · Axial length
- · Anterior chamber depth
- · Pupil diameter
- · White-to-white distance (WTW)
The IOLMaster 700 is a non-invasive optical biometry instrument for visualization and measurement of ocular structures. The IOLMaster 700 is the latest generation device in the IOLMaster series. The version of the IOLMaster 700 that is the subject of this submission is a modified version of the IOLMaster 700 cleared under K170171.
Here's a breakdown of the acceptance criteria and study details for the IOLMaster 700 device, based on the provided FDA 510(k) summary.
It's important to note that this document is for a 510(k) submission, which primarily aims to demonstrate substantial equivalence to a predicate device. Therefore, the "acceptance criteria" discussed are largely about demonstrating comparability or non-inferiority to the predicate device and established clinical methods, rather than setting absolute performance thresholds for a novel device. The study design reflects this goal.
1. Table of Acceptance Criteria and Reported Device Performance
Since this is a 510(k) for a modified device, the "acceptance criteria" are not explicitly stated as numerical targets in the same way they might be for a de novo device. Instead, the performance data aims to demonstrate that the new features (Total Keratometry and Posterior Corneal Surface measurements) are either:
- Interchangeable with conventional methods for normal eyes.
- Perform better than or comparably to existing history-free approximation methods (like Haigis-L) for post-LVC eyes, especially when historical data is unavailable.
- And that repeatability and reproducibility are comparable to the conventional keratometry.
The reported performance is summarized in the "Results" sections of the clinical studies. For the purpose of this table, I will infer the acceptance criteria from the conclusions drawn by the manufacturer regarding comparability and suitability.
| Metric/Parameter | Acceptance Criteria (Inferred from Study Goals) | Reported Device Performance (Summary) |
|---|---|---|
| Normal Eyes - Interchangeability | ||
| Spherical Equivalent of TK vs. Conventional Keratometry | Mean difference and limits of agreement (Bland-Altman) show interchangeability. | Mean difference close to zero, narrow 95% LOA (e.g., TSE vs. SE [D]: Mean 0.013, SD 0.110, 95% LOA [0.233, -0.206]) - Concluded as interchangeable. |
| Cylinders of TK vs. Conventional Keratometry | Systematic difference expected and aligns with scientific literature (TK overcomes weakness of conventional keratometry). | Mean difference for TΔD vs. ΔD [D] was -0.032, SD 0.183. WTR: -0.147, ATR: 0.185. - Concluded TK differs systematically as expected and accounts for posterior cornea better. |
| Normal Eyes - Repeatability & Reproducibility | ||
| SE_TK Repeatability SD | Comparable to conventional keratometry (implied). | Non-cataract: 0.090 D; Cataract: 0.088 D. |
| CYL_TK Repeatability SD | Comparable to conventional keratometry (implied). | Non-cataract: 0.159 D; Cataract: 0.148 D. |
| A_TK Repeatability SD | Comparable to conventional keratometry (implied). | Non-cataract: 2.998°; Cataract: 3.459°. |
| SE_PCS Repeatability SD | Comparable to conventional keratometry (implied). | Non-cataract: 0.030 D; Cataract: 0.029 D. |
| CYL_PCS Repeatability SD | Comparable to conventional keratometry (implied). | Non-cataract: 0.047 D; Cataract: 0.048 D. |
| A_PCS Repeatability SD | Comparable to conventional keratometry (implied). | Non-cataract: 4.319°; Cataract: 7.371°. |
| Post-LVC Eyes - Performance vs. Gold Standard/Benchmark | ||
| TK vs. Clinical History Method (CHM) (Spherical Equivalent) | TK yields results closer to CHM than Haigis-L (established history-free method) does. | Individual differences above noise/clinical significance. However, TK "much closer" to CHM than Haigis-L (as shown by tighter distribution in Figure 1). |
| TK vs. CHM (Toric/Cylinder) | TK yields results closer to CHM than Haigis-T (established history-free method) does. | Mean vector differences for TK vs. CHM (0.049 D @ 41.03°) superior to Haigis-TL vs. CHM (0.172 D @ 173.59°) (Figure 2). |
| Post-LVC Eyes - Repeatability & Reproducibility | ||
| SE_TK Repeatability SD | Comparable to conventional keratometry (implied). | 0.083 D. |
| CYL_TK Repeatability SD | Comparable to conventional keratometry (implied). | 0.135 D. |
| A_TK Repeatability SD | Comparable to conventional keratometry (implied). | 5.416°. |
| SE_PCS Repeatability SD | Comparable to conventional keratometry (implied). | 0.027 D. |
| CYL_PCS Repeatability SD | Comparable to conventional keratometry (implied). | 0.044 D. |
| A_PCS Repeatability SD | Comparable to conventional keratometry (implied). | 11.236°. |
2. Sample Sizes and Data Provenance
-
Test Set (Clinical Data):
- Normal Eyes (Study IOLM71): 142 normal eyes (without previous surgery or pathologies except cataract), 738 measurements. (Provenance: Raw data collected prospectively, non-significant risk clinical study at three sites, described as "normal eyes = without prior Laser Vision Correction").
- Normal Eyes (Study IOLMaster 2017-01909): 32 non-cataract eyes (281 measurements) and 31 cataract eyes (278 measurements). (Provenance: Prospective, monocentric, non-significant risk clinical R&R study, one eye per patient).
- Post-LVC Eyes (Study HamburgLVC): 30 eyes, 60 measurements (one pre- and one post-operative measurement for each eye). 29 myopic LASIK, 1 hyperopic LASIK. (Provenance: Prospective, single-site clinical study, one eye per patient).
- Post-LVC Eyes (Study IOLMaster 2017-01909): 30 post-LVC eyes, 267 measurements. (Provenance: Prospective, monocentric, non-significant risk clinical R&R study, one eye per patient).
- Country of Origin: Not explicitly stated, but the mention of "HamburgLVC" suggests Germany for at least one study site. The applicant "Carl Zeiss Meditec AG" is based in Germany.
-
Training Set: Not explicitly mentioned in this 510(k) summary, as the device improvements are primarily related to algorithms for new measurement calculations (Total Keratometry, Posterior Cornea Surface) derived from existing OCT technology, rather than an AI/ML model that requires explicit "training" in the traditional sense. The software verification and validation are for the overall product, and bench testing with "test targets of known curvatures" was used for accuracy and repeatability of the new measurement calculations.
3. Number of Experts and their Qualifications for Ground Truth
- Not applicable in the context of this 510(k). This device is a measurement instrument. The ground truth for the performance of the measurements is based on:
- Bench testing with "test targets of known curvatures."
- Comparison to existing, established clinical measurement methods (conventional keratometry, Gullstrand model, Clinical History Method for post-LVC eyes).
- The "experts" involved would be the clinicians conducting the clinical studies and presumably validating the established methods used for comparison. The document does not specify the number or qualifications of these clinicians beyond them being study site personnel.
4. Adjudication Method for the Test Set
- Not applicable. This study is focused on the performance of a measurement device. There is no subjective interpretation being adjudicated. The measurements are quantitative.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No. This is not an imaging device where human readers interpret and then AI assists in that interpretation. It is a biometric measurement device. The studies compare the device's measurements to established measurement methods.
6. Standalone (Algorithm Only) Performance
- Yes, implicitly. The device itself performs the measurements for Total Keratometry and Posterior Corneal Surface (via its software algorithm). The performance data (Table 1, Figure 1, Figure 2, Tables 2, 3) represent the output of the device's algorithms. There isn't a human-in-the-loop component for these specific measurements; the device generates the numbers. The clinical data then validates these algorithm outputs against established clinical practices.
7. Type of Ground Truth Used
- For Accuracy/Deviation:
- Known Reference Standards: Bench testing used "test targets of known curvatures."
- Established Clinical Methods/Models:
- Conventional keratometry and the Gullstrand model (for normal eyes).
- Clinical History Method (CHM) for post-LVC eyes, which is considered the "gold standard" when historical data is available.
- For Repeatability & Reproducibility:
- Multiple measurements on the same patients/eyes using the device itself across different scans, and sometimes different devices/operators.
8. Sample Size for the Training Set
- Not applicable / Not stated. This 510(k) describes a device that utilizes "Spectral domain interferometry (OCT principle)" and "Swept source laser" to obtain biometric measurements. The improvements are primarily algorithmic enhancements to interpret these optical measurements for new parameters (TK, PCS). It's not described as a machine learning model that undergoes a distinct "training set" phase in the typical AI/ML sense. Bench testing and clinical data validate the performance of these algorithms.
9. How the Ground Truth for the Training Set was Established
- Not applicable / Not stated as there is no explicitly defined "training set" for an AI/ML model. The underlying physics and algorithms are based on established optical principles (OCT, interferometry). The validation data compares the device's output to established clinical measurement techniques and physical standards.
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Image /page/0/Picture/0 description: The image contains 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.
Carl Zeiss Meditec AG % Lisa Graney Consultant Biologics Consulting Group, Inc. 1555 King Street, Suite 300 Alexandria, Virginia 22314
Re: K173771
Trade/Device Name: IOLMaster 700 Regulation Number: 21 CFR 886.1850 Regulation Name: AC-Powered Slitlamp Biomicroscope Regulatory Class: Class II Product Code: HJO Dated: December 11, 2017 Received: July 18, 2018
Dear Lisa Graney:
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.
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
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801); medical device 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.htm); good manufacturing practice requirements as set forth in the quality systems (OS) 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 (DICE@fda.hhs.gov) or phone
(1-800-638-2041 or 301-796-7100).
Sincerely,
Alexander Beylin -S 2018.08.24 14:15:53 -04'00'
for Malvina Eydelman, M.D. Director Division of Ophthalmic and Ear, Nose, and Throat Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K173771
Device Name IOLMaster 700
Indications for Use (Describe)
The IOLMaster 700 is intended for biometric measurements and visualization of ocular structures. The measurements and visualization assist in the determination of the appropriate power and type of intraocular lens. The IOLMaster 700 measures:
- · Lens thickness
- · Corneal curvature and thickness
- · Axial length
- · Anterior chamber depth
- · Pupil diameter
- · White-to-white distance (WTW)
| Type of Use (Select one or both, as applicable) |
|---|
| ------------------------------------------------- |
X Prescription Use (Part 21 CFR 801 Subpart D)
| Over-The-Counter Use (21 CFR 801 Subpart C)
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510(k) Summary
In accordance with 21 CFR 807.87(h) and (21 CFR 807.92) the 510(k) Summary for the IOLMaster 700 is provided below:
1. SUBMITTER:
| Applicant: | Carl Zeiss Meditec AGGoeschwizer Strasse 51-52D-07745 JenaGermany |
|---|---|
| Contact: | Lisa GraneyConsultantBiologics Consulting Group, Inc.1555 King Street, Suite 300Alexandria, VA 22314(571) 777-9518lgraney@biologicsconsulting.com |
Date Prepared: July 18, 2018
2. DEVICE:
| Device Trade Name: | IOLMaster 700 |
|---|---|
| Device Common Name: | Biometer |
| Classification Name: | 21 CFR 886.1850, AC-powered slit lampbiomicroscope |
| Regulatory Class: | Class II |
| Product Code: | HJO |
PREDICATE DEVICE: 3.
The predicate device is the previous version of the IOLMaster 700, cleared under K170171.
DEVICE DESCRIPTION: 4.
The IOLMaster 700 is a non-invasive optical biometry instrument for visualization and measurement of ocular structures. The IOLMaster 700 is the latest generation device in the
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IOLMaster series. The version of the IOLMaster 700 that is the subject of this submission is a modified version of the IOLMaster 700 cleared under K170171.
INDICATIONS FOR USE: 5.
"The IOLMaster 700 is intended for biometric measurements and visualization of ocular structures. The measurements and visualization assist in the determination of the appropriate power and type of intraocular lens. The IOLMaster 700 measures:
- Lens thickness .
- Corneal curvature and thickness
- . Axial length
- Anterior chamber depth .
- Pupil diameter
- White-to-white distance (WTW) •
TECHNOLOGICAL COMPARISON: 6.
| DEVICE CHARACTERISTICS | PROPOSED IOLMASTER 700(CARL ZEISS MEDITEC AG) | PREDICATE IOLMASTER 700(CARL ZEISS MEDITEC AG)K170171 |
|---|---|---|
| Principles of Operation | Spectral domain interferometry (OCTprinciple),Light spot projection (infrared LEDs),Image capturing | Identical |
| Feature - Corneal Curvature Measurement: | ||
| Keratometry (consideringanterior corneal surface) | Available | Available |
| Technology for obtainingmeasurements/images | Telecentric keratometry = distanceindependent,Light spot projection (infrared LEDs) | Identical |
| Measurement range /Resolution of display | 5 mm to 11 mm / 0.01 mm | Identical |
| Total Keratometry (consideringanterior and posterior cornealsurface) calculated by SWalgorithm | Available (with additional algorithm) | Not available |
| Total Keratometry measurementvalues: | ||
| Spherical Equivalent (TSE) [D] | Available | Not available |
| Corneal cylinder (TAD) [D] | Available | Not available |
| Axis (Tα) [°] | Available | Not available |
| Posterior corneal surfacemeasurement values: | ||
| Spherical Equivalent (PSE) [D] | Available | Not available |
| Corneal cylinder (PAD) [D] | Available | Not available |
| Axis (Pα) [°] | Available | Not available |
| Feature - Lens Thickness Measurement (LT): | ||
| Technology for obtainingmeasurements/images | Swept source laser,Spectral domain interferometry (OCTprinciple),Multiple A-scans provide a B-scan | Identical |
| Measurement range /Resolution of display | Phakic eye range1.0 mm to 10 mm / 0.01 mmPseudophakic eye range0.13 mm to 2.5 mm / 0.01mm | Identical |
| Feature - Central Corneal Thickness Measurement (CCT): | ||
| Technology for obtainingmeasurement | Swept source laser,Spectral domain interferometry (OCTprinciple),Multiple A-scans provide a B-scan | Identical |
| Measurement range /Resolution of display | 0.2 mm to 1.2 mm / 1 μm | Identical |
| Feature - Anterior Chamber Depth Measurement (ACD): | ||
| Technology for obtainingmeasurement | Swept source laser,Spectral domain interferometry (OCTprinciple),Multiple A-scans provide a B-scan | Identical |
| Measurement range /Resolution of display | 0.7 mm to 8 mm / 0.01 mm | Identical |
| Feature - Axial Length Measurement (AL): | ||
| Technology for obtainingmeasurement | Swept source laser,Spectral domain interferometry (OCTprinciple),Multiple A-scans provide a B-scan | Identical |
| Measurement range /Resolution of display | 14 mm to 38 mm / 0.01 mm | Identical |
| Feature - Pupil Diameter Measurement (P): | ||
| Technology for obtainingmeasurement | Image capturing of the iris with internaldigital camera. | Identical |
| Measurement range /Resolution of display | 1 mm to 12 mm / 0.1 mm | Identical |
| Feature - White-to-White Measurement (WTW): | ||
| Technology for obtainingmeasurement | Image capturing of the iris with internaldigital camera. | Identical |
| Measurement range /Resolution of display | 8 mm to 16 mm / 0.1 mm | Identical |
| Feature - Reference Image Functionality: | ||
| Technology for obtainingmeasurement | Green LEDs for green light illuminationfor image capturing of scleral vessels withinternal digital camera. | Identical |
| Feature - Computationalformulas | Haigis Suite (includes Haigis, Haigis-Land Haigis-T);Hoffer Q;Holladay 2;SRK®/T;Barrett Suite (includes Barrett UniversalII, Barrett Toric and Barrett True K);Holladay 1 | Haigis Suite (includes Haigis,Haigis-L and Haigis-T);Hoffer Q;Holladay 2;SRK®/T |
| Optical radiation: | ||
| Illumination for OCT | Light source: Tunable laserWavelength range: 1035 nm to 1080 nmMaximum power output: 1.67 mWMax. exposure time per eye and day: 8 h | Identical |
| Illumination for keratometer(corneal curvature) measurement | Light source: LEDWavelength: 950 nmDelivered power: < 500 µW | Identical |
| Illumination for WTWmeasurement | Light source: LEDWavelength: 860 nm/880 nmDelivered power: < 500 µW | Identical |
| Green illumination for scleraimages | Source: LEDWavelength: 520 nmDelivered power: < 100 µWMax. exposure time per eye and day:27 min (corresponding to approx. 3000measurements ) | Identical |
| Fixation light | Source: LEDWavelength: 660 nmDelivered power: < 1 µW | Identical |
| Electrical Data: | ||
| Rated voltage / frequency | 100 V to 240 V AC (± 10 %) / 50/60 Hz | Identical |
| Power consumption:Basic unitIn standby mode | 150 W1 W | Identical |
| Electrical Safety Parameters: | ||
| Protection class | I | Identical |
| Protection mode | IP 20 | Identical |
| Device type | B (IEC 60601-1) | Identical |
| Laser class | Class 1 (IEC 60825-1:2007)In device (not accessible): 3B | Identical |
| Ambient conditions: | ||
| for intended use | Temperature: 10°C to +35°C,Relative humidity: 30% to 80%(noncondensing) | Identical |
| for storage and transport | Temperature: -20°C to +60°C,Relative humidity: 10% to 90%(noncondensing) | Identical |
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7. PERFORMANCE DATA:
7.1. Biocompatibility Testing:
The device materials are identical to the predicate device. Therefore, patient contact information is not needed for this device.
7.2. Electromagnetic Compatibility, Electrical, Thermal, Mechanical, Laser and Optical Radiation Safety Testing:
No hardware changes have been made from the predicate IOLMaster 700 (K170171); therefore, no EMC, electrical, thermal, mechanical, laser, or optical radiation safety testing is provided in this submission.
7.3. Software Verification and Validation Testing:
Software verification and validation testing was conducted and documentation was provided as recommended by FDA's Guidance for Industry and FDA Staff, "Guidance for the Content of
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Premarket Submissions for Software Contained in Medical Devices." Verification and validation of the IOLMaster 700 was conducted to ensure that the product works as designed.
7.4. Bench Testing:
To verify the accuracy and repeatability of the IOLMaster 700 when making posterior corneal surface (PCS) and Total Keratometry (TK) measurements, bench testing was conducted in which the device acquired images of test targets of known curvatures. The results are then compared to the expected values and differences from the expected values must be within the tolerance range identified. This testing showed that the modified IOLMaster 700 is able to acquire posterior corneal surface (PCS) and Total Keratometry (TK) measurements which are accurate and repeatable.
Animal Testing: 7.5.
Not applicable. Animal studies are not necessary to establish the substantial equivalence of this device.
7.6. Clinical Data:
Clinical studies were conducted to obtain raw image data of normal eyes1 (cataract and noncataract) as well as post LVC eyes. The image data were analyzed using the Total Keratometry (TK) / posterior corneal surface (PCS) measurement algorithm in the modified IOLMaster 700 (subject device) and compared to conventional keratometry in the predicate device IOLMaster 700.
The objectives of this testing were as follows:
- . To characterize the relationship between TK and conventional keratometry measurements.
- To characterize the relationships between PCS measurements and the respective Gullstrand model eye-derived assumptions.
- To characterize the repeatability and reproducibility of TK and PCS measurements. ●
7.6.1. Normal eyes (Cataract and non-cataract eyes)
-
a) Clinical study IOLM71
The following raw data was used for testing the stated objectives: -
Raw data collected within a prospective, non-significant risk clinical study conducted at three sites.
-
Collection of the data using the same measurement and image acquisition method as the ● current IOLMaster 700.
-
Eyes with low to high cylinder were enrolled in the study. ●
1 Normal eyes = without prior Laser Vision Correction
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- Included datasets consisted of 142 normal eyes (i.e. without previous surgery or any ● known pathologies except for cataract) and 738 measurements in the normal (i.e. without previous surgery or any known pathologies except for cataract).
b) Clinical study IOLMaster 2017-01909
The following data were used for repeatability and reproducibility analysis:
- Prospective, monocentric, non-significant risk clinical R&R study. ●
- Collection of the data at study site employed three IOLMaster 700 devices.
- Included datasets consisted of 32 non-cataract eyes and 281 measurements as well as 31 cataract eyes and 278 measurements. Only one eye of each patient was included.
Results
- a) Clinical study IOLM71
For each of the normal eye PCS measurements and TK values (spherical equivalent, cylinder, axis) were compared to conventional keratometry and Gullstrand model derived posterior corneal surfaces.
Additionally, to address variability, Bland-Altman testing was conducted to assess the agreement of:
- the spherical equivalents of TK and keratometry in normal eyes, ●
- the cylinders of TK and keratometry in normal eyes,
- the cylinders of TK and keratometry in normal eyes with with-the-rule (WTR) and against-the-rule (ATR) astigmatism,
- the axis with AD ≥ 0.75 D of TK and keratometry in normal eyes, ●
- the spherical equivalents of PCS and keratometry-Gullstrand ratio-derived PCS in normal eyes
- the cylinders of PCS and keratometry-Gullstrand ratio-derived PCS in normal eves
- the axis with PAD ≥ 0.1 D of PCS and keratometry in normal eyes.
Results are summarized in Table 1.
Abbreviations used in Table 1:
- SE Spherical equivalent of corneal power according to keratometry [D]
- AD Cylinder of corneal power according to keratometry [D]
- Axis of the steep meridian according to keratometry [°] ರ
- TSE Spherical equivalent of corneal power according to TK [D]
- TAD Corneal cylinder of corneal power according to TK [D]
- Ta Axis of the steep meridian according to TK [°]
- PSE Spherical equivalent of posterior corneal power [D]
- PAD Cylinder of posterior corneal power [D]
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- Axis of the steep meridian of posterior corneal power [°] Pa
- WTR With-the-rule astigmatism, where the steep meridian is roughly vertical.
- Against-the-rule astigmatism, where the steep meridian is roughly horizontal. ATR
| Difference | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Parameter | N | Mean | SD | Min | Med | Max | 95% CI forMean | p-value | 95% LOA | |
| Keratometry | ||||||||||
| PSE vs. PSEKera [D] | 141 | 0.027 | 0.114 | -0.301 | 0.031 | 0.414 | 0.019, 0.036 | < 0.001 | 0.255, -0.200 | |
| PΔD vs. PΔDKera [D] | 129 | -0.150 | 0.132 | -0.511 | -0.158 | 0.225 | -0.160, -0.140 | < 0.001 | 0.114, -0.414 | |
| Pα vs. α [°]PΔD ≥ 0.1 D | 117 | -3.409 | 31.152 | -88.187 | -2.326 | 87.786 | -5.879, -0.939 | 0.007 | 58.896, -65.713 | |
| TSE vs. SE [D] | 141 | 0.013 | 0.110 | -0.303 | 0.016 | 0.383 | 0.005, 0.022 | 0.002 | 0.233, -0.206 | |
| TΔD vs. ΔD [D] | 129 | -0.032 | 0.183 | -0.444 | -0.038 | 0.441 | -0.046, -0.018 | < 0.001 | 0.334, -0.398 | |
| WTR | 76 | -0.147 | 0.110 | -0.444 | -0.155 | 0.138 | -0.158, -0.136 | < 0.001 | 0.074, -0.367 | |
| ATR | 33 | 0.185 | 0.120 | -0.081 | 0.193 | 0.441 | 0.167, 0.204 | < 0.001 | 0.424, -0.054 | |
| Tα vs.α [°]ΔD ≥ 0.75 D | 84 | 0.603 | 3.416 | -14.828 | 0.579 | 10.725 | 0.278, 0.927 | < 0.001 | 7.434, -6.228 |
Table 1: Mean Difference Summary Statistics
b) Clinical study IOLMaster 2017-01909
Repeatability standard deviation (SD) was estimated by the square-root of the estimated variance due to measurement error based on the random effect ANOVA model. The repeatability limit (or repeatability) was estimated with a 95% confidence limit of the difference between two repeated measurements. The reproducibility SD was estimated by the square-root of sum of the variances due to device/operator configuration, interaction between subject, and measurement error. Additionally, the coefficient of variation in percentage (CV) for repeatability were provided.
Results are summarized in Table 2.
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| Table 2: Repeatability and Reproducibility, normal patients (n = 32 non-cataract subjects and n =31 cataract subjects), IOLMaster 700 version 1.70 / Repeatability Analysis |
|---|
| Population |
| NScans | Mean | Repeatability | Reproducibility | |||||
|---|---|---|---|---|---|---|---|---|
| Scans | Mean | SD | Limit | CV% | SD | Limit | CV% | |
| Non-cataract Subjects | ||||||||
| SE_TK [D] | 281 | 43.59 | 0.090 | 0.251 | 0.21% | 0.093 | 0.261 | 0.21% |
| CYL_TK [D] | 281 | -1.38 | 0.159 | 0.446 | 11.55% | 0.173 | 0.485 | 12.55% |
| A_TK [°](CYL K ≥ 0.75D) | 219 | 136.46 | 2.998 | 8.393 | 2.20% | 3.393 | 9.499 | 2.49% |
| SE_PCS [D] | 281 | -5.88 | 0.030 | 0.085 | 0.52% | 0.033 | 0.091 | 0.55% |
| CYL_PCS [D] | 281 | -0.36 | 0.047 | 0.132 | 13.06% | 0.052 | 0.145 | 14.31% |
| A_PCS [°] | 281 | 139.19 | 4.319 | 12.093 | 3.10% | 5.424 | 15.188 | 3.90% |
| Cataract Subjects | ||||||||
| SE_TK [D] | 278 | 44.16 | 0.088 | 0.246 | 0.20% | 0.103 | 0.288 | 0.23% |
| CYL_TK [D] | 278 | -1.01 | 0.148 | 0.416 | 14.69% | 0.159 | 0.446 | 15.77% |
| A_TK [°](CYL K ≥ 0.75D) | 171 | 133.79 | 3.459 | 9.685 | 2.59% | 3.854 | 10.791 | 2.88% |
| SE_PCS [D] | 278 | -5.92 | 0.029 | 0.080 | 0.48% | 0.035 | 0.097 | 0.58% |
| CYL_PCS [D] | 278 | -0.27 | 0.048 | 0.133 | 17.43% | 0.048 | 0.136 | 17.75% |
| A_PCS [°] | 278 | 145.12 | 7.371 | 20.640 | 5.08% | 8.949 | 25.058 | 6.17% |
(SE_TK, CYL_TK, A_TK) = Spherical equivalent, Cylinder, Axis IOLMaster 700 v1.70 Total Keratometry, (SE_PCS, CYL_PCS, A_PCS) = Spherical equivalent, Cylinder, Axis IOLMaster 700 v1.70 Posterior Corneal Surface Reproducibility Limit = 2.8*SD.
Note: poststratification of IOLMaster 700 v 1.70 axis (A_TK) is based on the per-patient median of the IOLMaster v1.50 Cylinder (CYL_K) measurement, cut at 0.75D.
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7.6.2. Post-LVC eyes
a) Clinical study HamburgLVC
For the quantitative comparison analyses, the data from the "HamburgLVC" study were examined
- Raw data collected within a prospective, single-site clinical study.
- Collection of the data using the same measurement and image acquisition method as the current IOLMaster 700.
- Eyes with low to high cylinder were enrolled in the study. Included datasets consists of 30 eyes and 60 measurements (one pre- and one postoperative measurement for each eye). From the 30 eyes, 29 eyes have undergone a myopic and one eye has undergone a hyperopic LASIK treatment. Only one eye of each patient was included.
b) Clinical study IOLMaster 2017-01909
The following data are used for repeatability and reproducibility analysis:
- Prospective, monocentric, non-significant risk clinical R&R study.
- Collection of the data at study site employed three IOLMaster 700 devices. ●
- . Included datasets consisted of 30 post-LVC eyes and 267 measurements. Only one eye of each patient was included.
Results
In post-LVC eyes, IOL calculation typically consists of two steps: correcting keratometry K values and using a standard formula. When the required historic data is available, the clinical history method is considered the gold standard for correcting K values. Otherwise, a history-free approximation, like Haigis-L, is typically used in clinical practice.
The dataset HamburgLVC includes post-LVC measurements and pre-LVC and post-LVC refraction data. This allows comparison of TK measurements to K values modified according to the clinical history method. As a benchmark, comparison of Haigis-L modified K values to the clinical history method was also conducted. The analysis was performed for non-toric lenses as well as for toric lenses.
Abbreviations in Figure 1 and Figure 2:
- SE Spherical equivalent of keratometry [D]
- TSE Spherical Equivalent for TK [D]
- CHM Clinical History Method
- CSE Spherical equivalent of postoperative corneal power derived from CHM
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Image /page/13/Figure/2 description: The image contains two scatter plots side by side, both titled "post-LASIK (HamburgLVC)". The left plot shows "TSE vs. CSE" with the y-axis labeled "Differences of devices [D]" and the x-axis labeled "subjective refraction change [D]". A dashed line indicates "Mean + 2SD = 0.78685" and another indicates "Mean - 2SD = -0.60124". The right plot shows "SE (Haigis-L) vs. CSE" with the same axis labels as the left plot. A dashed line indicates "Mean + 2SD = 1.4485" and another indicates "Mean - 2SD = -0.12801".
Figure 1: Distribution of disagreement of the spherical equivalents of TK and CHM (left), and of Haigis-L and CHM (right) by subjective refraction change in case of post LASIK eyes. The teal dot marks the hyperopic post-LVC measurement.
Image /page/13/Figure/4 description: The image contains two polar plots comparing power vector differences between different methods for LASIK surgery. The plot on the left compares 'HH-LVC TK' versus 'CHM', with a mean difference of 0.049D at 41.03 degrees. The plot on the right compares 'HH-LVC Haigis-TL' versus 'CHM', with a mean difference of 0.172D at 173.59 degrees. Both plots display data points distributed around the center, with radial lines indicating diopter values and angular lines indicating degrees.
- Figure 2: Double-angle plots of vector differences between corneal cylinder of TK and toric CHM (left), and as a baseline of Haigis-T corrected keratometry and toric CHM (right), respectively. The mean vector differences are 0.049 D @ 41. 03° (left) and 0.172 D @ 173.59° (right).
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c) Clinical study IOLMaster 2017-01909
Repeatability standard deviation (SD) was estimated by the square-root of the estimated variance due to measurement error based on the random effect ANOVA model. The repeatability limit (or repeatability) was estimated by the 95 % confidence limit of the difference between two repeated measurements. The reproducibility SD was estimated by the square-root of sum of the variances due to device/operator configuration, interaction between subject, and measurement error. Additionally, the coefficient of variation in percentage (CV) for repeatability were provided.
Results are summarized in Table 3.
| NScans | Mean | SD | RepeatabilityLimit | CV% | SD | ReproducibilityLimit | CV% | |
|---|---|---|---|---|---|---|---|---|
| SE_TK [D] | 267 | 40.64 | 0.083 | 0.233 | 0.21 | 0.092 | 0.257 | 0.23 |
| CYL_TK [D] | 267 | -0.91 | 0.135 | 0.379 | 14.82 | 0.148 | 0.414 | 16.19 |
| A_TK [°](CYL_K ≥ 0.75D) | 231 | 150.85 | 5.416 | 15.165 | 3.59 | 5.510 | 15.428 | 3.65 |
| SE_PCS [D] | 267 | -5.91 | 0.027 | 0.076 | 0.46 | 0.034 | 0.094 | 0.57 |
| CYL_PCS [D] | 267 | -0.31 | 0.044 | 0.124 | 14.45 | 0.048 | 0.135 | 15.77 |
| A_PCS [°] | 267 | 153.01 | 11.236 | 31.462 | 7.34 | 11.345 | 31.767 | 7.41 |
Table 3: Repeatability and Reproducibility, post LVC patients (n = 30), IOLMaster 700 version 1.70 / Repeatability Analysis Population
(SE TK, CYL TK, A TK) = Spherical equivalent, Cylinder, Axis IOLMaster 700 v 1.70 Total Keratometry, (SE PCS, CYL PCS, A PCS) = Spherical equivalent, Cylinder, Axis IOLMaster 700 v1.70 Posterior Corneal Surface
Reproducibility Limit = 2.8*SD.
Note: poststratification of IOLMaster 700 v 1.70 axis (A_TK) is based on the per-patient median of the IOLMaster v1.50 Cylinder (CYL K) measurement, cut at 0.75D.
7.6.3. Conclusion
Normal eyes
The analysis of the data shows that the spherical equivalent of Total Keratometry (TK) and of the conventional keratometry are interchangeable for normal eyes - non-cataract and cataract eyes based on analysis of the mean difference and limits of agreement.
Hence, TK analysis in the modified IOLMaster 700 can be used for IOL power calculation of non-toric IOLs in normal (spherical) eyes as an alternative to conventional keratometry in the predicate IOLMaster 700.
The verification shows that TK astigmatism measurements systematically differ from keratometry as expected and in agreement with scientific literature. The results show that TK overcomes the systematic weakness of keratometry in accounting for the contribution of the posterior cornea surface to the corneal astigmatism.
Combined with the interchangeability in spherical equivalent, TK is thus suitable for IOL power calculation of toric IOLs using existing keratometry-based formulas, but not for formulas including a model of the posterior corneal astigmatism that differs from the keratometer model as a workaround of the weakness of keratometry.
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The repeatability and reproducibility of TK and PCS is comparable to conventional keratometry.
Post-LVC eyes
The analysis for post-LVC eyes shows that TK measurements systematically differ from keratometry measurements in this patient group as expected. Analysis also shows that TK overcomes the systematic weakness of keratometry in accounting for changes in the back-ratio due to LVC treatment.
Individual differences between TK and the clinical history method (CHM), which is considered the established gold standard, are above the noise level and above the limit of clinical significance. However, analysis of the relative performance of the Haigis-L formula, which is an established history-free alternative to CHM, showed that TK yields results much closer to CHM results than the Haigis-L results are to CHM results.
Combined with the interchangeability in spherical equivalent in normal eyes, TK combined with a regular IOL calculation formula (e.g. Haigis) is a valid tool for IOL calculation in post-LVC eyes, particularly in cases after myopic LASIK without availability of the historic data required for CHM.
Therefore, TK analysis in the modified IOLMaster 700 can be used for IOL power calculation of both toric and non-toric IOLs in post-LVC eyes as an alternative to conventional keratometry in the predicate IOLMaster 700.
It is further concluded that the repeatability and reproducibility of TK and PCS is comparable to the that of conventional keratometry.
CONCLUSION: 8.
All testing deemed necessary was conducted on the modified IOLMaster 700 to ensure that the device is as safe and effective when used in accordance with its Instructions for Use as the predicate device.
The differences in technological characteristics do not raise different questions of safety and effectiveness and the results of performance testing demonstrate that the subject device performs in accordance with specifications and meets user needs and intended uses.
Clinical data demonstrated that TK can be used as an alternative to conventional keratometry for IOL power calculation in both normal eyes and post LASIK Vision Correction eyes for both spherical and astigmatic eyes.
Based on the detailed comparison of specifications for each of the modifications to the previously cleared IOLMaster 700, the results of performance testing and clinical testing the modified IOLMaster 700 is substantially equivalent to the predicate device IOLMaster 700, as cleared in K170171.
§ 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.