Pupil Tracking for Real-Time Motion Corrected Anterior Segment Optical Coherence Tomography

• Published in: PloS one Vol. 11; no. 8; p. e0162015
• Main Authors: Carrasco-Zevallos, Oscar M, Nankivil, Derek, Viehland, Christian, Keller, Brenton, Izatt, Joseph A
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 30.08.2016; Public Library of Science (PLoS)
• Subjects: Angiography; Anterior Eye Segment - anatomy & histology; Biology and Life Sciences; Biomedical engineering; Diagnosis; Digitization; Engineering; Engineering and Technology; Eye; Eye diseases; Eye movements; Field of view; Humans; Imaging, Three-Dimensional; In vivo methods and tests; Lasers; Medical imaging; Medicine and Health Sciences; Motion; Motion compensation; Optical Coherence Tomography; Optical tomography; Optics; Physical Sciences; Pupil - physiology; Real time; Research and Analysis Methods; Retina; Retinal images; Risk factors; Systems design; Tomography; Tomography, Optical Coherence - methods; Tracking; Tracking systems; United States; North Carolina; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0162015

Volumetric acquisition with anterior segment optical coherence tomography (ASOCT) is necessary to obtain accurate representations of the tissue structure and to account for asymmetries of the anterior eye anatomy. Additionally, recent interest in imaging of anterior segment vasculature and aqueous humor flow resulted in application of OCT angiography techniques to generate en face and 3D micro-vasculature maps of the anterior segment. Unfortunately, ASOCT structural and vasculature imaging systems do not capture volumes instantaneously and are subject to motion artifacts due to involuntary eye motion that may hinder their accuracy and repeatability. Several groups have demonstrated real-time tracking for motion-compensated in vivo OCT retinal imaging, but these techniques are not applicable in the anterior segment. In this work, we demonstrate a simple and low-cost pupil tracking system integrated into a custom swept-source OCT system for real-time motion-compensated anterior segment volumetric imaging. Pupil oculography hardware coaxial with the swept-source OCT system enabled fast detection and tracking of the pupil centroid. The pupil tracking ASOCT system with a field of view of 15 x 15 mm achieved diffraction-limited imaging over a lateral tracking range of +/- 2.5 mm and was able to correct eye motion at up to 22 Hz. Pupil tracking ASOCT offers a novel real-time motion compensation approach that may facilitate accurate and reproducible anterior segment imaging.