Assessment of binocular alignment using the three-dimensional Strabismus Photo Analyzer

Br J Ophthalmol. 2012 Jan;96(1):78-82. doi: 10.1136/bjophthalmol-2011-300305. Epub 2011 Oct 8.

Abstract

Aim: To evaluate the efficacy of the three-dimensional (3D) Strabismus Photo Analyzer for estimating binocular alignment using photographs.

Methods: Thirty-two subjects with exotropia, 30 subjects with esotropia and 38 orthotropic subjects were included. Two independent ophthalmologists examined the angle of deviation using the Krimsky test and prism and alternate cover test (PCT). Full-face photographs were obtained using an 8.2-megapixel digital single-lens reflex camera, and the images were analysed using the 3D Strabismus Photo Analyzer. The images were adjusted for age-dependent ophthalmic biometry and angle κ. The main outcome measures were inter-observer variability, test-retest reliability and correlation between the angles of deviation measured by different methods.

Results: The 95% limit of agreement of inter-observer variability was ± 3.5° (6.1 prism dioptres (PD)), ± 3.1° (5.4 PD) and ± 1.5° (2.6 PD) for the Krimsky test, PCT and the 3D Strabismus Photo Analyzer, respectively. The test-retest reliability was ± 2.8° (4.9 PD) for the 3D Strabismus Photo Analyzer versus the Krimsky test. The results of the Krimsky test and 3D Strabismus Photo Analyzer showed a strong positive correlation.

Conclusions: The 3D Strabismus Photo Analyzer is a simple and reliable tool for measuring ocular deviation. It has excellent agreement with the Krimsky test and substantially improved reproducibility.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Cornea / anatomy & histology
  • Diagnostic Techniques, Ophthalmological / instrumentation*
  • Diagnostic Techniques, Ophthalmological / standards
  • Diagnostic Techniques, Ophthalmological / statistics & numerical data
  • Esotropia / diagnosis*
  • Exotropia / diagnosis*
  • Female
  • Humans
  • Imaging, Three-Dimensional / methods*
  • Imaging, Three-Dimensional / standards
  • Imaging, Three-Dimensional / statistics & numerical data
  • Infant
  • Male
  • Middle Aged
  • Models, Biological
  • Observer Variation
  • Photography / methods*
  • Photography / standards
  • Photography / statistics & numerical data
  • Reproducibility of Results
  • Young Adult