We use phase-sensitive optical coherence tomography (OCT) to measure the deformation of the optic nerve head during the pulse cycle, motivated by the possibility that these deformations might be indicative of the progression of glaucoma. A spectral-domain OCT system acquired 100k A-scans per second, with measurements from a pulse-oximeter recorded simultaneously, correlating OCT data to the subject’s pulse. Data acquisition lasted for 2 seconds, to cover at least two pulse cycles. A frame-rate of 200–400 B-scans per second results in a sufficient degree of correlated speckle between successive frames that the phase-differences between fames can be extracted. Bulk motion of the entire eye changes the phase by several full cycles between frames, but this does not severely hinder extracting the smaller phase-changes due to differential motion within a frame. The central cup moves about 5 μm/s relative to the retinal-pigment-epithelium edge, with tissue adjacent to blood vessels showing larger motion.

Date Published: 26 March 2013
PDF: 9 pages
Proc. SPIE 8567, Ophthalmic Technologies XXIII, 85670M (26 March 2013);

Published in SPIE Proceedings Vol. 8567:
Ophthalmic Technologies XXIII
Fabrice Manns; Per G. Söderberg; Arthur Ho, Editor(s)