Eyeworld

EW FEATURE 72 IOL calculations February 2015 by EyeWorld staff Many physicians customize their formula choice for each patient T here are a variety of IOL calculation formulas cur- rently in use in the U.S. and abroad, and choice depends on several surgeon- and patient-related factors. "IOL choice and selection of IOLs is a personal thing, and every doctor has his or her preferences for particular cases," said Sumit "Sam" Garg, MD, Gavin Herbert Eye Institute, University of California, Irvine. "Generally, in shorter eyes, we hedge toward the Hoffer Q. For normal eyes, we choose the Holladay 1, and for longer eyes, we use SRK/T. Doug Koch [MD] and colleagues have a modification that you can use for patients with really long axial lengths." "The Holladay 2 [available on Holladay IOL Consultant Software] is a great formula that takes into account more variables than some of the other formulas," he said. "Newer versions of the IOLMaster [Carl Zeiss Meditec, Jena, Germany] and LENSTAR [Haag-Streit, Koniz, Switzerland] have direct links to the software. The major drawback is that you have to pay to use it." The Hoffer Q, Holladay 1, and SRK/T use 2 biometric measure- ments and a single IOL constant. The Haigis formula uses 3 measure- ments and 3 IOL constants, and the Holladay 2 formula uses 7 measurements and 1 IOL constant. The Olsen formula uses 5 measure- ments and 1 IOL constant. In the 2014 ASCRS Clinical Sur- vey, ASCRS members were surveyed about their preferred lens formula for the majority of cataract surgeries. Of the U.S. respondents, the major- ity (29.8%) prefer the Holladay 2, 27.9% prefer to use multiple for- mulas based on axial length, 19.2% prefer the SRK/T, 15.4% prefer the Holladay 1, 3.8% prefer the SRK II, and 2.9% prefer Haigis. In contrast, most of the non-U.S. respondents (24.2%) prefer multiple formulas based on axial length, 22.1% prefer Haigis, 18.9% prefer SRK/T, 13.7% prefer Holladay 2, 10.5% prefer SRK II, 7.4% prefer Holladay 1, and 1.1% prefer Hoffer Q. The difference in responses between U.S. and non-U.S. surgeons was statistically significant. Warren E. Hill, MD, Mesa, Ariz., was not surprised by the discrepancy in the preferences between U.S. surgeons and non-U.S. surgeons. "Haigis has always been a popular formula for European ophthalmologists due to the fact that it is readily available on most biometers and it is familiar," Dr. Hill said. "Here in the United States, Holladay 2 has steadily increased in IOL calculations: U.S. and international surgeons differ on formula preference popularity over the past 5 years, due mostly to a combination of ease of use [it is resident on the IOLMaster 500 and an automatic import feature from the LENSTAR] and increasing pressure from patients for optimal outcomes." Dr. Hill uses the Holladay 2, Olsen, and Barrett Universal II formulas. "Lately, I have come to trust the Olsen and Barrett Universal II formulas the most. In a large series of patients I recently reviewed, Olsen and Barrett had the best ASCRS members were surveyed about their preferred lens formula for the majority of cataract surgeries. Source: ASCRS 2014 ASCRS Clinical Survey

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