A machine vision method for automated alignment of fundus imaging systems

Michele Moscaritolo, Frederick P. Knezevich, Ingrid Zimmer-Galler, Henry Jampel, Ran Zeimer

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


■ BACKGROUND AND OBJECTIVE: To report a method to track the pupil in three axes simultaneously prior to imaging the fundus. ■ PATIENTS AND METHODS: The system is based on parallax optical alignment to detect the center of the pupil. The system consists of two cameras acquiring pupil images from two distinct directions and an operator-supervised algorithm to derive the coordinates of the pupil center and output of commands to drive a three-axes computer-controlled stage. The system was tested in a cohort of 45 individuals 61 ± 15 years of age, 26 with and 19 without glaucoma. The tracking was performed without pharmacologic pupil dilation. ■ RESULTS: The variability of the pupil center determination (assessed by the standard deviation) was ± 0.19 and ± 0.33 mm for the vertical and horizontal directions, respectively. The processing time of the algorithm was 0.75 msec. The tracking converged to within a preset tolerance of ± 0.5 mm in 45 of the 45 eyes. ■ CONCLUSION: Image acquisition and processing of pupil images can be used to align fundus imaging systems rapidly, accurately, and with minimal operator intervention.

Original languageEnglish (US)
Pages (from-to)607-613
Number of pages7
JournalOphthalmic Surgery Lasers and Imaging
Issue number6
StatePublished - Nov 2010

ASJC Scopus subject areas

  • Surgery
  • Ophthalmology


Dive into the research topics of 'A machine vision method for automated alignment of fundus imaging systems'. Together they form a unique fingerprint.

Cite this