title: Computer-vision-enabled augmented reality fundus biomicroscopy.
abstract: OBJECTIVE
  To guide treatment for macular diseases and to facilitate real-time image measurement and comparison, investigations were initiated to permit overlay of previously stored photographic and angiographic images directly onto the real-time slit-lamp biomicroscopic fundus image.
  
  
  METHODS
  Experimental study in model eyes, and preliminary observations in human subjects.
  
  
  METHODS
  A modified, binocular video slit lamp interfaced to a personal computer and framegrabber allows for image acquisition and rendering of stored images overlaid onto the real-time slit-lamp biomicroscopic fundus image. Development proceeds with rendering on a computer monitor, while construction is completed on a miniature display interfaced directly with one of the slit-lamp oculars. Registration and tracking are performed with in-house-developed software.
  
  
  METHODS
  Tracking speed and accuracy, ergonomic acceptability.
  
  
  RESULTS
  Computer-vision algorithms permit robust montaging, tracking, registration, and rendering of previously stored photographic and angiographic images onto the real-time slit-lamp fundus biomicroscopic image. In model eyes and in preliminary studies in a human eye, optimized registration permits near-video-rate image overlay with updates at 3 to 10 Hz and misregistration errors on the order of 1 to 5 pixels.
  
  
  CONCLUSIONS
  A prototype for ophthalmic augmented reality (image overlay) is presented. The current hardware/software implementation allows for robust performance.
authors.affiliation: Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia 19104, USA. jwberger@mail.med.upenn.edu
authors.forename: J W
authors.initials: JW
authors.lastname: Berger
authors.forename: D S
authors.initials: DS
authors.lastname: Shin
mesh_terms: D000465:Algorithms; D020256:Choroidal Neovascularization / Q000473:pathology*; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D008268:Macular Degeneration / Q000473:pathology*; D008853:Microscopy; D008953:Models, Anatomic