Axial length measurements: Comparison of a new swept-source optical coherence tomography–based biometer and partial coherence interferometry in myopia

Abstract

To compare axial length (AL) measurements between a swept-source optical coherence tomography (SS-OCT) biometer (IOLMaster 700) and a partial coherence interferometry (PCI) biometer (IOLMaster, version 5.4) in myopic eyes. Severance Hospital, Yonsei University, Seoul, South Korea. Prospective evaluation of a diagnostic test. This study enrolled patients with a diagnosis of myopia in their medical records. Two consecutive AL measurements were performed in each eye in random order using the 2 biometers. Subanalysis was performed according to lens status, fixation status, degree of myopia, and the presence of posterior staphyloma. The interdevice agreement was evaluated with Bland-Altman analyses and paired t tests. This study comprised 219 eyes of 117 patients. During a fixation check using SS-OCT, 19.6% of eyes showed fixation loss. Overall, the SS-OCT biometer showed a longer AL than the PCI biometer. (P<.001) In a subanalysis that categorized eyes according to lens status, fixation status, degree of myopia, and the presence of posterior staphyloma, the SS-OCT biometer also showed longer ALs than the PCI biometer. Ofeyes with good fixation, significant differences in AL measurements between devices were detected for those with posterior staphyloma (P<.001) but not for those without posterior staphyloma (P=.104). The 2 devices showed differences in AL measurements in myopic eyes. Fixation status and the presence of posterior staphyloma were important factors in these differences.For myopic eyes with posterior staphyloma, the SS-OCT biometer is expected to produce more precise AL measurements because it allows evaluation of the fixation status.