Repeatability and reproducibility of ocular biometry using a new noncontact optical low-coherence interferometer

J Cataract Refract Surg. 2015 Oct;41(10):2233-41. doi: 10.1016/j.jcrs.2015.10.062.


Purpose: To assess the precision of ocular biometry with a new noncontact optical low-coherence interferometer (Aladdin) in healthy subjects and patients with cataracts.

Setting: Eye Hospital of Wenzhou Medical University, Wenzhou, China.

Design: Observational cross-sectional study.

Methods: Eyes from healthy subjects and eyes from patients with cataracts were examined with the new interferometer. Axial length (AL), anterior chamber depth (ACD), keratometry (K), and white-to-white (WTW) values were measured by 2 operators. The test-retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability. Different-operator comparison was analyzed with paired t tests and Bland-Altman plots to assess interoperator reproducibility.

Results: Ninety-eight people were enrolled for this study, of which 52 eyes were from healthy subjects and 46 eyes were from patients with cataracts. The AL was the most repeatable and reproducible parameter. The ACD, K values, and WTW measurements were highly repeatable in healthy subjects with CoV less than 0.89% and ICC more than 0.94. However, in patients with cataracts, high repeatability could only be observed for AL, ACD, and K values, whereas WTW measurement had test-retest repeatability of 0.80 mm and an ICC of 0.795. Bland-Altman analysis also showed good agreement between the 2 operators for ocular component measurements, except that the WTW in patients with cataracts had wider 95% limits of agreement (range -0.88 to 0.95 mm).

Conclusion: The new biometer showed excellent intraoperator repeatability and interoperator reproducibility for AL, ACD, and K values measurements in both groups. The precision of WTW measurements was lower in patients with cataracts.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anterior Chamber / pathology*
  • Axial Length, Eye / pathology*
  • Biometry / instrumentation*
  • Cataract / complications*
  • Cataract Extraction
  • Cornea / pathology*
  • Cross-Sectional Studies
  • Female
  • Healthy Volunteers
  • Humans
  • Interferometry*
  • Lenses, Intraocular
  • Light
  • Male
  • Middle Aged
  • Observer Variation
  • Prospective Studies
  • Reproducibility of Results
  • Young Adult