Comparative Analysis of Axial Length Measurements by Optical Biometers Based on Partial Coherence Interferometry Versus Optical Low-Coherence Interferometry: An Office Audit

Purpose In this study, we aimed to compare axial length (AL) measurements of the IOLMaster 500 (Carl Zeiss Meditec AG, Jena, Germany), based on partial coherence interferometry (PCI) versus the Aladdin (Topcon Healthcare, Oakland, NJ), based on optical low-coherence interferometry (OLCI), in a clinical setting. Methods A retrospective analysis of the records of patients presenting for cataract surgery at an ophthalmology practice between October 2019 and March 2020 was performed. All patients had biometry measurements on the IOLMaster 500 and the Aladdin. Data collected included patient demographics, cataract morphology and type, and AL measurements. The IOLMaster 500 and Aladdin measurements were compared using the unpaired t-test and Chi-squared test. Results In total, 393 eyes (197 patients) were included (91 males, 107 females) in the study. The IOLMaster 500 was unable to successfully obtain AL measurements in seven eyes (1.8%) and the Aladdin in 26 eyes (6.6%). The difference was statistically significant (p=0.0007). Advanced and central posterior subcapsular cataracts were common in eyes that had unsuccessful measurements. In the eyes successfully measured, the mean AL for the IOLMaster was 24.04 ±1.32 mm, while it was 24.04 ±1.34 mm for the Aladdin. However, this difference was not statistically significant (p=0.9165). Conclusion The IOLMaster 500 performed better in terms of the number of eyes for which AL measurements were successfully obtained compared to the Aladdin. This may be partly related to high volumes of advanced cataracts treated at our practice. However, this being a retrospective study, a cause-and-effect relationship could not be established.