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The IOLMaster was the first optical biometer; the IOLMaster 700 (Figure 1) now incorporates swept-source OCT technology, making it the first swept-source biometry device, claims manu-

facturer Carl Zeiss Meditec.1 The features of this device can help users to decrease refractive sur-prises and improve refractive outcomes, according to company literature.

Swept-source biometry provides a full-length OCT image of the eye, showing anatomic details in a longitudinal cut through the length of the organ. Depiction of this image allows identifica-tion of unusual features of ocu-lar geometry such as crystalline lens tilt or decentration, which could contribute to suboptimal surgical outcomes if undetected. The OCT image also provides a fix-ation check: If the image shows the foveal pit, the user knows that the patient achieved proper fixation; if not, the patient can be educated to fixate better on the target.

The full-length OCT image of the IOLMaster 700 also displays measurement calipers so the user can visually verify what ana-tomic structures are being measured, rather than having to interpret which peak on an A-scan is the feature of interest. According to company literature, the

swept-source device performs 2,000 scans per second. Anatomic measurements include the biometric parameters

required for modern IOL power calculation formulas, including central corneal thickness, lens thickness, axial

length, and anterior chamber depth.

SOFTWARE AND OTHER FEATURESSoftware on the IOLMaster 700 includes the Haigis Suite, an all-in-one

solution combining the Haigis IOL power calculation formula with the Haigis-L formula for eyes after laser refractive surgery and the new Haigis-T formula for toric IOL cal-culations. With the onboard toric calculator, there is no need to key in

refractive data to IOL manufacturers’ online calculators. Although the device is new, it is

compatible with earlier versions of the IOLMaster, so that the User Group of Laser Interference Biometry database can be used. The database contains lens constants for more than 270 IOLs based on data from more than 50,000

surgeries collected specifically for the IOLMaster, according to the company, and these data can be used to help refine refractive outcomes.

The device also offers what the company calls tel-ecentric keratometry, which is a distance-independent approach that allows

Full-length OCT image of the eye allows identification of unusual features of ocular geometry.

BY TIM DONALD, CONSULTING EDITOR

IOLMASTER 700: A DEBUT OF SWEPT-SOURCE OCT TECHNOLOGY

(Image courtesy of Carl Zeiss M

editec)

Figure 1. The swept-source OCT technology of the

IOLMaster 700 provides a full-length OCT image of

the eye. (Continued on page 69)

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Commentary

Expertsfrom the

Highlights of the IOLMaster 700 in Clinical Practice

By Ekkehard Fabian, MD

What is your overall impression of the IOLMaster 700?We have routinely used the IOLMaster (Carl Zeiss Meditec) since 1999. We started using the IOLMaster 500 in 2010, and, in August 2014, we added the IOLMaster 700.

With the help of optical biometry and the use of optimized A-constants—published in

the User Group of Laser Interference Biometry (ULIB) database—collectively, cataract surgeons can achieve much better predict-ability in refractive outcomes than we could in 1999. With that said, the majority of surgeons continue to come within ±0.50 D of the intended correction in only 78% of patients, thus necessitating enhancements in some of those cases.1 One of the weak points for better predictability is estimation of the effective lens position. Even if the C-constant is of help,2 this factor remains an estimating tool.

I have been impressed by my early experience with the IOLMaster 700.

How do you use the IOLMaster 700 in clinical practice?

Our experience with the IOLMaster 700 in the past 11 months includes about 1,000 patient examinations. We now use this technology as part of our daily examination routine. The multi-touchscreen and graphical user interface help to speed up the examinations, which are delegated to our assistant personnel. Integrated power calculations in the new Haigis Suite (Haigis-L and Haigis-T formulas) make it unnecessary to key data into online toric IOL calculators. Thus, in our practice, the IOLMaster 700 was immediately accepted.

In our office and ambulatory surgical center, we have 40 computer workplaces that integrate with Tomedo (http://www.tomedo.de/faq.html), our office’s practice management system. This server-based software runs on Mac OS 10.9.5 and integrates with the Forum eye care data management system (Carl Zeiss Meditec). Thus, we can transfer patient data via Forum into the IOLMaster 500 and 700 and can redirect IOLMaster data into Forum, allowing us to display all data at every workplace and also in the operating room (Figure 1). We can also use these data with the Zeiss Cataract Suite markerless and Callisto eye (both by

Carl Zeiss Meditec). Thus, the reference image of the IOLMaster and the online image of the OPMI Lumera microscope, aligned through Callisto eye, enable computer assistance for the sur-geon (Figure 2), resulting in better centered, larger, and rounder capsulorrhexes and markerless alignment of toric IOLs. About 95% of alignments performed in our center are fully automatic; the residual 5% need interactive but still markerless alignment (Figures 3 and 4).

According to comparative measurements taken with the

Figure 1. OCT detected morphologic structures (green lines).

Figure 2. In this example, the limbal region with conjunctival

vessels is seen. The IOLMaster reference image aligns with the

image from the microscope; the fold-out reference image and

microscope image can be adjusted on the touchscreen of Callisto.

(Images courtesy of Ekkehard Fabian, M

D)

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repeatable measurements even for restless patients. A multitouch screen gives users a means to employ gesture controls on the graphical user interface similar to those used on smartphones and tablets. Measurement tasks can be delegated because alignment functions make results largely independent of the user.

When a toric IOL is to be implanted, the IOLMaster 700 can operate as a part of the Zeiss Cataract Suite markerless, a platform that also includes the IOLMaster 500, Callisto eye, and OPMI Lumera family of microscopes (all devices by Carl Zeiss Meditec). For any eye with astigmatism, the

biometry device can acquire a reference image taken at the same time as the keratometric measurement, and these data can be transferred to the Callisto Eye computer-assisted cataract surgery system.

During the surgical procedure, the reference image can be matched to the live microscope image of the OPMI Lumera. All relevant data are then displayed in the eye-piece of the surgical microscope, so that preoperative corneal marking and other procedures for toric IOL align-ment are not needed. n

1. The new IOLMaster 700. Carl Zeiss website. http://www.zeiss.com/meditec/en_de/products---solutions/ophthalmolo-gy-optometry/cataract/diagnostics/optical-biometry/iolmaster-700.html#highlights. Accessed June 5, 2015.

IOLMaster 500 and IOLMaster 700 in 84 eyes, the differences in axial length and keratometry mea-surements between the devices were 0.02 mm and 0.08 D, respectively. Also, 99.4% of the mea-surements taken with the IOLMaster 700 were predicted with the IOLMaster

500, and that is highly significant. Thus, the ULIB database is also valid for the IOLMaster 700.3

What are the advantages of the IOLMaster 700 compared with other ocular biometry technologies?

With regard to measuring ocular structures for biometry, this is the first time that OCT technology can be used to project mor-phologic structures, control fixation with the macula, and control IOL position pre- and postoperatively. Also, the decentration or tilt of the crystalline lens and the IOL can be registered.

As the IOLMaster 700 continues to mature as a technology, we expect additional features, such as measurement of more rings with keratometry and of anterior and posterior corneal surfaces for calculation of corneal thickness. These are the next steps for optimizing refractive outcomes.

1. Hill WE. Paper presented at: the Eyeworld Symposium, Master Your Toric Planning for Improved Refractive Outcomes With the Lenstar LS 900; ASOA/ASCRS Annual Meeting; April 17-21, 2015; San Diego. 2. Olson T, Hoffmann P. C constant: New concept for ray tracing-assisted intraocular lens power calculation. J Cataract Refract Surg. 2014;40(5):764-773. 3. Fabian E. Comparison of two biometers: Partial coherence biometer versus new swept source OCT biometer related to biometric data. Paper presented at: the ASCRS Annual Meeting; April 17-21, 2015; San Diego.

Ekkehard Fabian, MDn AugenCentrum, Rosenheim, Germanyn prof.fabian@augencentrum.den Financial disclosure: Consultant (Carl Zeiss Meditec, Abbott

Medical Optics)

Figure 3. A centered and large capsulorrhexis, with overlay

assisted by Callisto eye.

Figure 4. The dotted line marks the

limbal region; the yellow line marks the

horizontal 0° axis; and the blue lines

indicate the steepest meridian.

Commentary

Expertsfrom the

Highlights of the IOLMaster 700 in Clinical Practice

(Continued)

(Continued from page 67)