EyeWorld India December 2021 Issue

CATARACT EWAP DECEMBER 2021 9 by Liz Hillman Editorial Co-Director Contact information Hoffer: khoffermd@startmail.com Loh: jenniferlohmd@gmail.com Shammas: hshammas@aol.com B iometry is essential for IOL power calculations, but when might you need a new biometer? What should you look for? What is there to know about this technology, how it evolved, and where it is today? If you’re going to start talking about biometry, the first stop is Kenneth J. Hoffer, MD. Dr. Hoffer was the first ophthalmologist in the U.S. to use an ultrasound biometer to measure the axial length of the eye for IOL power calculations in 1974. In 1999, he was the first in the country to use an optical biometer and conduct a study that found optical biometry was easier and more accurate than ultrasound immersion biometry. Dr. Hoffer said he has been the first U.S. physician to use or try every optical biometer that’s been introduced in the country. “I became the grandfather of IOL power calculations and biometry just by hanging around a long time,” Dr. Hoffer said. Biometry history In April 1974, Dr. Hoffer first used an ultrasound biometer to measure axial length for a lens power calculation. “There were ophthalmologists in the United States who were doing lens implantation, but there weren’t any sophisticated calculations. They were implanting an 18 D lens in every patient’s eye. If you had a patient who was a –9 D myope, Looking for a new biometer? Here’s what you need to know restricted by thick glasses, they’d get an implant and be a –9 D postop. Obviously, if you could adjust the lens implant power, you could get them out of glasses overall,” he said. Dr. Hoffer learned of A-scan biometers that could measure the length of the eye when he was at a course in Long Island, New York, in 1972. He said he initially laughed and wondered who would care about the length of the eye. The ophthalmologist who introduced this device, Dr. Hoffer said, had the last laugh because Dr. Hoffer called him 2 years later to ask the name of the machine, acquired one, and used the measurement for a lens power calculation for his first IOL implantation using his new Hoffer formula. In 1999, Dr. Hoffer said he became the first ophthalmologist in the Western Hemisphere to acquire an IOLMaster 500 (Carl Zeiss Meditec), the first optical biometer. Ten years later, in 2009, he gained access to the LENSTAR LS900 (Haag-Streit). Dr. Hoffer said he now has access to every optical biometer. When to consider a new biometer The first reason one might want a new biometer is if it isn’t functioning properly. If it is functioning and producing accurate results, Dr. Hoffer said it’s still useful. “If you have a biometer, whether it’s an ultrasound or optical, and it’s working properly, an ophthalmologist doesn’t need to every 5 or even 10 years turn around and buy a new biometer,” he said. There are three things you want out of a biometer, Dr. Hoffer said: axial length, corneal power and astigmatism, and anterior chamber depth. “There are other things you can get but those are the essentials,” he said. If an ophthalmologist wants the latest and greatest technology—and can afford it —that’s another reason to consider a new machine. These newer options have several refinements and technological improvements that are nice to have but not essential, according to Dr. Hoffer. H. John Shammas, MD, told EyeWorld he could think of two reasons why it might be time for an ophthalmologist to think about getting a new biometer. One scenario is in a busy cataract practice. “It will enhance the workflow, and there will be a substantial savings in time evaluating eyes prior to surgery. The newer biometers have a much higher acquisition rate, especially in dense cataracts with less dependence on A-scan immersion biometry,” he said. Another scenario is for the ophthalmologist who has a 10-year-old (or older) biometer. “[I]t might make sense to acquire a new one instead of This article originally appeared in the September 2021 issue of EyeWorld . It has been slightly modified and appears here with permission from the ASCRS Ophthalmic Services Corp.