Assessment of Hoffer Correction Factor for Biometry in Eyes with Phakic Intraocular Lens Implants

To assess Hoffer correction factor in measurement of axial length (AL) in eyes with phakic IOL implants. In this descriptive historical cohort study, axial length was measured by ultrasound (US) and IOL Master in both phakic and pseudophakic modes in 24 eyes of 14 patients with Artisan intraocular lenses (IOLs) implanted for refractive purposes, Hoffer’s suggested formula for correcting ultrasound AL was applied to the data (cor-US) and all four datasets were compared to preoperative ultrasound AL values as standards. The mean difference between preoperative ultrasound measurements and postoperative readings by US (ALpo), IOLMaster in phakic mode (AL IOLMp), IOL Master in pesudophakic mode (AL IOLMpp) and US corrected with Hoffer factor (ALhc), were 0.01, 0.022, 0.13, and 0.61mm, with mean absolute differences of 0.23, 0.23, 0.26, and 0.25mm, respectively. In these readings, respectively 42.3%, 37.5%, 57.5%, and 46.2% of differences were greater than 0.2 mm, which is considered to be clinically important. Use of the Hoffer correction factor has no clinical application for a more accurate biometry in patients with an Artisan implant. The most reliable method in this type of patients is making an accurate record of their preoperative AL measured with ultrasound or IOL Master.