The OCT penlight: In-situ image guidance for microsurgery

John Galeotti, Areej Sajjad, Bo Wang, Larry Kagemann, Gaurav Shukla, Mel Siegel, Bing Wu, Roberta Klatzky, Gadi Wollstein, Joel S. Schuman, George Stetten

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We have developed a new image-based guidance system for microsurgery using optical coherence tomography (OCT), which presents a virtual image in its correct location inside the scanned tissue. Applications include surgery of the cornea, skin, and other surfaces below which shallow targets may advantageously be displayed for the naked eye or low-power magnification by a surgical microscope or loupes (magnifying eyewear). OCT provides real-time highresolution (3 micron) images at video rates within a two or more millimeter axial range in soft tissue, and is therefore suitable for guidance to various shallow targets such as Schlemm's canal in the eye (for treating Glaucoma) or skin tumors. A series of prototypes of the "OCT penlight" have produced virtual images with sufficient resolution and intensity to be useful under magnification, while the geometrical arrangement between the OCT scanner and display optics (including a half-silvered mirror) permits sufficient surgical access. The two prototypes constructed thus far have used, respectively, a miniature organic light emitting diode (OLED) display and a reflective liquid crystal on silicon (LCoS) display. The OLED has the advantage of relative simplicity, satisfactory resolution (15 micron), and color capability, whereas the LCoS can produce an image with much higher intensity and superior resolution (12 micron), although it is monochromatic and more complicated optically. Intensity is a crucial limiting factor, since light flux is greatly diminished with increasing magnification, thus favoring the LCoS as the more practical system.

Original languageEnglish (US)
Title of host publicationMedical Imaging 2010
Subtitle of host publicationVisualization, Image-Guided Procedures, and Modeling
EditorsKenneth H. Wong, Michael I. Miga
ISBN (Electronic)9780819480262
StatePublished - 2010
EventMedical Imaging 2010: Visualization, Image-Guided Procedures, and Modeling - San Diego, United States
Duration: Feb 14 2010Feb 16 2010

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceMedical Imaging 2010: Visualization, Image-Guided Procedures, and Modeling
Country/TerritoryUnited States
CitySan Diego


  • Canaloplasty
  • Glaucoma
  • Image guided intervention
  • Image guided procedure
  • In-situ
  • Microsurgery
  • OCT
  • Optical coherence tomography
  • Penlight
  • Schlemm's canal

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


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