Abstract
Purpose: :
To demonstrate the feasibility of using multiple overlapping scans of the posterior pole to create a macular montage of Spectral-Domain OCT (SDOCT) images so that the complete area of geographic atrophy (GA) can be reconstructed in patients with age related macular degeneration (AMD)
Methods: :
Patients with geographic atrophy secondary to AMD were enrolled in an ongoing prospective SDOCT study at the Bascom Palmer Eye Institute and imaged using the Cirrus high-definition OCT (Carl Zeiss Meditec, Inc., Dublin, CA). Routinely, eyes were imaged using the 200 A-scan by 200 B-scan raster pattern contained within a 6mmX6mm area. The acquired three-dimensional data can be used to create an OCT Fundus Image (OFI). For inclusion in this study, the GA lesions had to extend outside the 6mmX6mm area of the OFI centered on the fovea. A montage technique was developed which utilized multiple scans surrounding the central 6mmX6mm area. The multiple OFIs were combined together to create a montaged OFI which represents a larger area of the posterior pole. Areas of GA were quantified from the reconstructed montage by exporting the files to a CintiQ WACOM digitizing tablet (WACOM Corp., Vancouver, WA) and the boundaries were drawn by hand.
Results: :
Out of 319 patients with GA scanned using the SDOCT protocol, 10 eyes of 10 patients were selected that demonstrated GA lesions extending outside the central 6mmX6mm area. The montage technique was used to generate an OFI with a larger sampled region of the retina, permitting visualization and quantification of the GA. The average total area at baseline was 16.09 mm2.
Conclusions: :
Multiple SDOCT scans of the posterior pole can be combined to create a macular montage so that macular lesions, such as GA, which extend outside the usual scanning area can be reconstructed and quantified.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • age-related macular degeneration • imaging/image analysis: clinical