Abstract
We acquired in vivo images of the human optic nerve head (ONH) using an adaptive optics-optical coherence tomography (AO-OCT) system. In order to improve imaging of the lamina cribrosa in the ONH with high lateral resolution and sensitivity, we implemented a complex conjugate artifact-free Fourier domain OCT (Fd-OCT) acquisition scheme with a reference arm-based phase shifting method. This allowed positioning of the lamina cribrosa structures near the zero path length difference where AO-OCT imaging achieves highest sensitivity. Implementation of our complex conjugate artifact removal (CCR) method required constant phase shifts between consecutive axial scans (A-scans), generated by continuous beam path-length changes from offsetting the pivot point of the scanning mirror placed in the reference arm. Fourier transform along the transverse axis and a filtering algorithm allowed reconstruction of CCR AO-OCT images. The suppression ratio of the mirror artifact was approximately 22 dB (at 18,000 A-scans per second acquisition speed) with a paperboard test target and an optimum phase-shift value. Finally, we reconstructed the three-dimensional structure of human ONH with enhanced depth range and sensitivity using CCR AO-OCT.
Original language | English (US) |
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Article number | 126005 |
Journal | Journal of Biomedical Optics |
Volume | 17 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2012 |
Keywords
- Aberration compensation
- Adaptive optics
- Complex conjugate artifact
- Imaging systems
- Medical optics instrumentation
- Ophthalmology
- Optical coherence tomography
ASJC Scopus subject areas
- Biomedical Engineering
- Biomaterials
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics