Snap–Shot Retinal Imaging Spectroscopy

Abstract

Abstract: : Purpose: Diagnostic imaging modalities used in ophthalmology are effective at conveying information about fundus structures but provide little data concerning the function of the retina. Retinal hyperspectral imaging has attracted recent interest for its ability to provide metabolic and physiological information. Detection and measurement of the unique spectral signatures associated with molecules such as hemoglobin and lipofuscin may be useful in determining the functional state of ocular tissues and in the identification of pathologic structures such as drusen. However, acquisition of this data has been hindered by long acquisition times, motion artifacts from saccades, and a poor understanding of informative spectral bands. Methods: We report on the development of a snap–shot imaging spectrometer that obtains a full spectral image cube with a single flash. The device, which is capable of operating at video rates, uses diffractive optics to multiplex the spatial/spectral information onto a focal plane. More than thirty bands can be captured simultaneously – providing a robust data set that can be retrospectively evaluated in future studies. Results: Images of fundus from a normal human subject were captured with this system and demonstrated good arteriovenous spectral distinction. Oxy– and deoxyhemoglobin spectra were also mapped onto retinal images and subjected to a forward simulation of the spectral reconstruction process which demonstrated good recovery of the input spectra. Conclusions: Snap–shot retinal imaging spectroscopy may be a useful method for detecting the presence of subtle pathology and monitoring retinal function both in a clinical and research setting.

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • age-related macular degeneration • diabetic retinopathy