Remote detection of binocular fixation and focus using polarization optics and retinal birefringence properties of the eye

Kristina Irsch

(Wilmer Eye Institute, John Hopkins School of Medicine)

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Date: July 14, 2015


Amblyopia (“lazy eye”) is a major public health problem, caused by misalignment of the eyes (strabismus) or defocus. If detected early in childhood, there is an excellent response to therapy, yet most children are detected too late to be treated effectively. Commercially available vision screening devices that test for amblyopia’s primary causes can detect strabismus only indirectly and inaccurately via assessment of the positions of external light reflections from the cornea, but they cannot detect the anatomical feature of the eyes where fixation actually occurs (the fovea). This talk presents an accurate and calibration-free technique for remote localization of the true fixation point of an eye by employing the characteristic birefringence signature of the radially arrayed Henle fibers delineating the fovea. Progress on the development of a medical diagnostic screening device for eye misalignment and defocus will be presented, and other potential applications will be discussed.

Further Information:

Kristina Irsch is a German physicist specializing in biomedical and ophthalmic optics. She received her Ph.D. from the University of Heidelberg in Germany where she trained under Josef F. Bille, Ph.D. She went to the Johns Hopkins University School of Medicine in Baltimore, Maryland in 2005, first as a visiting graduate student, and later completed a post-doctoral research fellowship in ophthalmic optics and instrumentation under David L. Guyton, M.D. before joining the faculty as Assistant Professor of Ophthalmology in 2010. Much of her research has focused on remote eye fixation and focus detection, using polarization optics and retinal birefringence properties of the eye, and its use in clinical settings. The main goal is to identify children with strabismus (misalignment of the eyes) and focusing abnormalities, at an early and still easily curable stage, before irreversible amblyopia (functional monocular visual impairment, or “lazy eye”) develops.

Created: Thursday, July 23rd, 2015