New pediatric vision screener employing polarization-modulated, retinal-birefringence-scanning-based strabismus detection and bull's eye focus detection with an improved target system: opto-mechanical design and operation

• Published in: Journal of biomedical optics Vol. 19; no. 6; p. 067004
• Main Authors: Irsch, Kristina, Gramatikov, Boris I, Wu, Yi-Kai, Guyton, David L
• Format: Journal Article
• Language: English
• Published: United States Society of Photo-Optical Instrumentation Engineers 01.06.2014
• Subjects: Adult; Aged; Algorithms; Amblyopia - diagnosis; Amblyopia - physiopathology; Assessments; Automation; Birefringence; Child; Child, Preschool; Design engineering; Diagnosis, Computer-Assisted; Diagnostic Techniques, Ophthalmological; Equipment Design; Eyes; Fixation; Fixation, Ocular; Fovea; Humans; Light reflection; Optics and Photonics; Retina - pathology; Retina - physiology; Signal-To-Noise Ratio; Strabismus - diagnosis; Vision; eye; polarized light; polarization-sensitive ophthalmic technology; strabismus; retina; cornea; amblyopia; vision screening; birefringence; ophthalmology
• ISSN: 1083-3668; 1560-2281; 1560-2281
• DOI: 10.1117/1.JBO.19.6.067004

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). Our laboratory has been developing technology to detect true foveal fixation, by exploiting the birefringence of the uniquely arranged Henle fibers delineating the fovea using retinal birefringence scanning (RBS), and we recently described a polarization-modulated approach to RBS that enables entirely direct and reliable detection of true foveal fixation, with greatly enhanced signal-to-noise ratio and essentially independent of corneal birefringence (a confounding variable with all polarization-sensitive ophthalmic technology). Here, we describe the design and operation of a new pediatric vision screener that employs polarization-modulated, RBS-based strabismus detection and bull's eye focus detection with an improved target system, and demonstrate the feasibility of this new approach.