SPOTLIGHT ON TECHNOLOGY & TECHNIQUE

Dense cataracts can’t hide anymore

America’s first swept-source biometer offers more thorough cataract measurements.

By Robert Stoneback, Associate Editor

Denser cataracts call for a biometer that can scan to their roots. Up until now, only cataracts in Europe and Asia received that treatment. Now, that treatment, a swept-source biometer, has arrived in America.

Zeiss’ IOLMaster 700 just received FDA approval this past fall, and studies out of Turkey and Thailand have shown it can penetrate more cataracts than its predecessor, the IOLMaster 500, which uses partial coherence interferometry to measure cataracts. This is in addition to its ability to create an image of the eye’s longitudinal cut, allowing physicians a full front-to-back view, and its faster performance.

One American ophthalmologist who has been using Zeiss biometers for years says each new model can penetrate denser cataracts. But this latest model, says Daniel Chang, MD, of Bakersfield, California’s, Empire Eye and Laser Center, provides even more.

The Zeiss IOLMaster 700 is the first swept-source biometer approved by the FDA.

AN UP-CLOSE LOOK

“No other biometer gives a single picture of the entire light path from the cornea to the fovea,” says Dr. Chang, who has been using the new 700 since last fall.

The IOLMaster series was the first biometer to pioneer the use of light to measure the eye, and now its swept-source feature allows it to collect data from the eye in three dimensions. This feature lets physicians zoom in on individual parts of the eye and more easily identify irregularities and confirm fixation. This is the first biometer to provide such a feature, says Dr. Chang.

The 700 is much faster than the 500, capable of scanning both patient’s eyes in less than a minute, which greatly speeds up his clinic’s workflow. Previous models would take several minutes to perform the same task. The IOLMaster 700 is also much more forgiving with patient positioning, which helped contribute to faster workflows.

FASTER AND FASTER

Improved speed is always important for taking measurements, as tear film can quickly break down and throw off any recordings, according to Dr. Chang. The improved speed doesn’t affect the device’s accuracy, as Dr. Chang says the 700 is at least as accurate with its refractive outcomes as the 500. Also impressive to Dr. Chang, when he was first examining data regarding the 700, was its tighter standard of deviations for length measurements.

The 700 retains compatibility with Zeiss’ User Group of Laser Interference Biometry database, which has optimized lens constants of more than 270 IOL models, according to Zeiss.

TESTED ABROAD

A study from December in Baskent University, of Ankara, Turkey, observed 181 eyes of 101 subjects, using both the IOLMaster 700 and 500. They found that axial length measurements in 17 eyes and anterior chamber depth in 13 eyes were impossible using the 500, while the 700 had no problems.

Of the 17 eyes in which axial lengths could not be measured by the IOLMaster 500, nine had posterior subcapsular cataracts and eight possessed dense nuclear cataracts.

The researchers concluded that the IOLMaster 700 was more effective at obtaining measurements in eyes with these conditions than its predecessor.¹

A second report, undertaken at Bangkok, Thailand’s, Mahidol University and published this past October, examined 100 eyes belonging to 100 cataract patients. Once again, readings were taking using both the IOLMaster 500 and the IOLMaster 700.

Similar to the test in Turkey, the researchers at Mahidol University found that the axial length of five eyes could only be obtained using the 700 and its swept-source technology. Mahidol University found that the 700 ultimately allowed for better lens penetration and axial length measurements than the 500.²

A STEP FORWARD

A favorite 700 feature for Dr. Chang is the 13-inch touch screen on the side of the biometer, which helps the user control the device. Learning these user-friendly controls was simpler for the Empire technicians than using the 5-inch screen and track pad to operate the previous model, says Dr. Chang.

“It’s a great device and a nice step forward in biometry,” says Dr. Chang. OM

Dr. Chang is a consultant for Carl Zeiss Meditec.

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