Simultaneous SLO/OCT imaging of the human retina in vivo with high speed axial eye motion correction

Abstract

Transversal scanning (or en-face) optical coherence tomography (TS-OCT) represents an imaging modality that is capable to record high isotropic resolution images of the human retina in vivo. However, axial eye motion still remains a challenging problem of this technique. In this paper we introduce an improved method of our previously published axial eye motion correction technique. To measure accurately the position of the cornea an auxiliary spectral domain partial coherence interferometer (SD-PCI) operating at 1310nm that is integrated into a TS-OCT system is used. The recorded corneal position is used to drive a rapid scanning optical delay line in the reference arm of the TS-OCT system to correct for axial eye motion. Currently, the correction can be performed with a rate of ~1kHz which is approximately 20 times faster than our previous system and practically eliminates axial eye motion artifacts. The TS-OCT instrument is operated with a line scan rate of 8000 transversal lines per second which enables simultaneous scanning laser ophthalmoscope (SLO) and OCT imaging at a frame rate of 40fps (650x200pixels).)