Multicenter study of optical low-coherence interferometry and partial-coherence interferometry optical biometers with patients from the United States and China

J Cataract Refract Surg. 2016 Jan;42(1):62-7. doi: 10.1016/j.jcrs.2015.07.041.


Purpose: To evaluate the agreement between the measurements provided by a new optical biometer, the Aladdin, based on optical low-coherence interferometry (OLCI), and those provided by the most commonly used optical biometer (IOLMaster 500), based on partial-coherence interferometry (PCI).

Setting: Multicenter clinical trial.

Design: Prospective evaluation of diagnostic test.

Methods: In this study, 2 samples of adult patients were enrolled, 1 in the United States and the other in China. The U.S. group included a sample of consecutive patients scheduled for cataract surgery. The China group included a sample of healthy subjects with no cataracts. In both cases, only 1 eye of each patient was analyzed. Axial length (AL), corneal power (in diopters [D]) (K), anterior chamber depth (ACD) (corneal epithelium to lens), and corneal astigmatism were measured. All values were analyzed using a paired t test, the Pearson product-moment correlation coefficient (r), and Bland-Altman plots.

Results: In the U.S. and China groups, the OLCI mean AL values did not show a statistically significant difference from PCI values and showed excellent agreement and correlation. On the contrary, OLCI measured a lower mean K (-0.14 D) and a deeper ACD measurements (U.S. +0.16 mm and China +0.05 mm). These differences were statistically significant (P < .0001). Vector analysis did not show a statistically significant difference in astigmatism measurements.

Conclusions: Agreement between OLCI and PCI was good. However, the small but statistically significant differences in K and ACD measurements make constant optimization necessary when calculating the intraocular lens power using theoretical formulas.

Financial disclosure: Dr. Hoffer licenses the registered trademark name Hoffer to Carl Zeiss-Meditec (PCI), Haag-Streit (Lenstar), Movu (Argos), Oculus (Pentacam, AXL), Nidek (AL-Scan), Tomey (OA-2000), Topcon EU Visia Imaging (Aladdin), Ziemer (Galilei G6), and all A-scan biometer manufacturers. Dr. Shammas licenses his formulas to Carl Zeiss-Meditec (PCI), Haag-Streit (Lenstar), Nidek (AL-Scan), and Topcon EU (Visia Imaging) (Aladdin). None of the other authors has a financial or proprietary interest in any material or method mentioned.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anterior Chamber / pathology*
  • Astigmatism / diagnosis
  • Axial Length, Eye / pathology*
  • Biometry / instrumentation*
  • Cataract / complications
  • Cataract / ethnology
  • Cataract Extraction
  • China
  • Cornea / pathology*
  • Ethnic Groups
  • Female
  • Healthy Volunteers
  • Humans
  • Interferometry / instrumentation
  • Light
  • Male
  • Middle Aged
  • Prospective Studies
  • Reproducibility of Results
  • United States
  • Young Adult