Complex conjugate artifact-free adaptive optics optical coherence tomography of in vivo human optic nerve head

J Biomed Opt. 2012 Dec;17(12):126005. doi: 10.1117/1.JBO.17.12.126005.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Artifacts*
  • Equipment Design
  • Equipment Failure Analysis
  • Humans
  • Image Enhancement / instrumentation*
  • Image Enhancement / methods*
  • Lenses
  • Middle Aged
  • Optic Disk / anatomy & histology*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tomography, Optical Coherence / instrumentation*
  • Tomography, Optical Coherence / methods*