Purchase this article with an account.
K. Singh, C. Dion, S. Costantino, M. Wajszilber, T. Ozaki, M. Lesk; Retinal Movement Measurement in a Live Rat Using Fourier Domain Low Coherence Interferometry. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4904.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Recent studies have shown that the biomechanical properties of the optic nerve head and/or sclera play an important role in the pathophysiolgy of glaucoma. However, there currently exists no technique with both sufficient time and spatial resolution to measure these biomechanical properties in vivo. In this work, we present an optical system capable of measuring in vivo the retinal movements in synchrony with the cardiac cycle to assess in real-time the biomechanics of the eye. We demonstrate the performance of the instrument on a rat subject.
The developed system couples a Fourier domain low coherence interferometry (FD-LCI) setup with an imaging system for proper positioning at the fundus. A broadband source is used to illuminate both the retina and a fixed reference surface. After recombining the reflected beams in a fiber coupler, a diffraction grating spatially separates the different wavelength components that form an interference pattern on a photodetector array. Fourier analysis of the spectral interference signal is digitally performed, which provides information on the relative position of the reflective interfaces in the sample relative to the reference surface. By tracking in real-time the variations in the interference signal and by digital signal processing, the displacement of the boundaries can be measured.
Typical A-Scan and movement of a rat retina are shown in Fig.1 and Fig.2 respectively. Instrument has a resolution of 200 nm in displacement measurements at 200 Hz sampling rate. Using this system, we found that rat retinal displacements produced by cardiac pulsations are approximately 15 µm.
This PDF is available to Subscribers Only