David L Cooke1, Timothy L Cooke2. 1. Great Lakes Eye Care, Saint Joseph, Michigan, USA; Department of Neurology and Ophthalmology, Michigan State University, College of Osteopathic Medicine, East Lansing, Michigan, USA. Electronic address: davidlcooke@gmail.com. 2. Great Lakes Eye Care, Saint Joseph, Michigan, USA.
Abstract
PURPOSE: To compare prediction accuracy with the axial length (AL) calculation method of the Lenstar biometer (traditional AL) and that of the ARGOS biometer (sum-of-segments AL). SETTING: Private practice clinic. DESIGN: Comparative case series. MAIN OUTCOME MEASURE: Mean absolute error (MAE). METHODS: Predictions were developed for nine formulas, grouping them into those derived with ultrasound (US) (SRK/T, Holladay 1 and 2, Hoffer Q, Haigis) and those derived with optical biometry (Barrett, OKULIX, Olsen from PhacoOptics, and Olsen from Lenstar). Formulas were ranked by MAE using sum-of-segments AL and traditional AL, in short eyes (traditional AL <22.0 mm), long eyes (traditional AL >26.0 mm), and all eyes. RESULTS: The study comprised 1442 eyes (54 short eyes and 67 long eyes) of 1070 patients. The best-ranking formula for long eyes was Haigis using sum-of-segments AL. For short eyes and for all eyes, OKULIX using sum-of-segments AL was best. Using sum-of-segments AL instead of traditional AL, Holladay 2 improved the most; Olsen from PhacoOptics worsened the most. CONCLUSIONS: Some biometers used traditional AL, and at least one used sum-of-segments AL. Formula accuracy varied depending on how various commercial biometers internally calculate AL. Using sum-of-segments AL instead of traditional AL improved predictions for formulas designed on US data (SRK/T, Holladay 1, Holladay 2, Hoffer Q, and Haigis), although it worsened the Barrett and Olsen formulas. OKULIX was generally improved with sum-of-segments AL. When ranking by MAE, OKULIX ranked first.
PURPOSE: To compare prediction accuracy with the axial length (AL) calculation method of the Lenstar biometer (traditional AL) and that of the ARGOS biometer (sum-of-segments AL). SETTING: Private practice clinic. DESIGN: Comparative case series. MAIN OUTCOME MEASURE: Mean absolute error (MAE). METHODS: Predictions were developed for nine formulas, grouping them into those derived with ultrasound (US) (SRK/T, Holladay 1 and 2, Hoffer Q, Haigis) and those derived with optical biometry (Barrett, OKULIX, Olsen from PhacoOptics, and Olsen from Lenstar). Formulas were ranked by MAE using sum-of-segments AL and traditional AL, in short eyes (traditional AL <22.0 mm), long eyes (traditional AL >26.0 mm), and all eyes. RESULTS: The study comprised 1442 eyes (54 short eyes and 67 long eyes) of 1070 patients. The best-ranking formula for long eyes was Haigis using sum-of-segments AL. For short eyes and for all eyes, OKULIX using sum-of-segments AL was best. Using sum-of-segments AL instead of traditional AL, Holladay 2 improved the most; Olsen from PhacoOptics worsened the most. CONCLUSIONS: Some biometers used traditional AL, and at least one used sum-of-segments AL. Formula accuracy varied depending on how various commercial biometers internally calculate AL. Using sum-of-segments AL instead of traditional AL improved predictions for formulas designed on US data (SRK/T, Holladay 1, Holladay 2, Hoffer Q, and Haigis), although it worsened the Barrett and Olsen formulas. OKULIX was generally improved with sum-of-segments AL. When ranking by MAE, OKULIX ranked first.
Authors: Achim Langenbucher; Nóra Szentmáry; Alan Cayless; Michael Müller; Timo Eppig; Simon Schröder; Ekkehart Fabian Journal: Ophthalmic Res Date: 2021-02-02 Impact factor: 2.892