EyeWorld India December 2021 Issue

CATARACT 10 EWAP DECEMBER 2021 servicing an older one,” he said. “Besides upgrading to a newer technology, he/ she will have access to the latest IOL power formulas.” Jennifer Loh, MD, went through the process of researching and choosing a new biometer for her practice earlier this year. She had originally purchased an IOLMaster 500 when she opened her practice 5 years ago. At the time, she wanted an optical biometer and went with an older model, which she said worked great for years. The biggest reason why she sought out a new biometer recently to replace her IOLMaster 500 was enhanced capabilities, such as having newer formulas programmed and being able to penetrate through denser cataracts. What to consider in a new biometer There are different technologies that achieve biometry measurements via different principles, such as partial coherence interferometry (PCI) or optical low-coherence reflectometry (OLCR). One of the newer options is swept- source OCT (SS-OCT). Two swept-source OCT biometers available in the U.S. are the IOLMaster 700 (Carl Zeiss Meditec) and ARGOS. “After 50 years in this field, if I felt the need or had to buy a new instrument, I would make sure it was a swept-source OCT because of the technology being so much better, even though the result is about the same,” Dr. Hoffer said. Dr. Shammas described swept-source OCT as “the new gold standard of biometry.” He said new swept-source biometers have simple and highly efficient interfaces for easier IOL power selection using newer formulas. Dr. Loh ended up purchasing an ARGOS. Prior to the switch, she said her older biometer was not able to penetrate through denser cataracts and she was having to switch to traditional ultrasound A-scans, which she said was not ideal for patients who wanted premium lenses. It was not only less accurate, but her technicians weren’t as familiar using the ultrasound biometer. It was more time consuming. In addition to the type of technology, Dr. Hoffer said one reason to consider a new biometer, and a factor to consider when selecting a biometer, is IOL power calculations. While you can find the formulas online and perform them manually, newer biometers do the calculation and provide a printout. Dr. Hoffer said the Hoffer Q, SRK/T, and Holladay 1 are the standby formulas that have been used for a long time, but some instruments have different and newer formulas. The formulas Dr. Hoffer recommended using—either online or via the biometer, when available—are the Kane formula, the Barrett Universal II, and the new Hoffer QST, all with printouts for the chart. “You can stick with the old formulas, but why [would you] when the new formulas are proven to provide better [outcomes],” he said. Dr. Loh said with her older biometer, she was having to go online and manually recalculate all of her IOLs. “I wanted to be accurate and meticulous so I would go online and type in the information. This was very time consuming, but there is also the risk for transcription errors. That’s what took me so long; I was triple checking. Here I was getting busier … and errors would have been devastating,” she said, explaining that a newer biometer with this capability would be accurate, convenient, and easy to use. Dr. Loh said she chose ARGOS because it had great data showing accuracy and reliability but also significant support, with the company training her and her staff. When she spoke to EyeWorld, she was 2 months into using the new technology and said she and her staff were impressed with how fast it was. “I don’t think since we’ve had it that I’ve had to do an A-scan, which is a huge relief,” she said. She also said the technology was easy to learn. She hired two new staff members with no prior ophthalmology experience and found they were able to easily learn how to use the machine. When it comes to considering a new biometer, Dr. Loh offered this additional advice: She said the device should show anterior chamber depth and data on the keratometry reading. “Reliability on K readings is critical, and make sure axial length and core measurements are accurate. Also, getting through a dense cataract is important,” she said. Dr. Shammas also said he thinks physicians should consider SS-OCT biometers when they’re seeking out new equipment, but perhaps consider one that is also a Scheimpflug tomographer. “As cataract surgeons, we are always looking for ways • Aladdin (Topcon) • AL-Scan (Nidek) • Anterion (Heidelberg, not approved in the U.S.) • ARGOS Biometer with Image Guidance (Alcon) • Galilei G-6 (Ziemer) • IOLMaster 700 (Carl Zeiss Meditec) • LENSTAR LS-900 (Haag - Streit) • OA-2000 (Tomey, not approved in the U.S.) • Pentacam AXL (Oculus) • REVO NX (Optopol, not approved in the U.S.) Modern biometers