To delineate pathologic changes in retinal cross sections obtained with spectral (Fourier) domain optical coherence tomography (SDOCT), so that the findings are maintained when collapsed into a two-dimensional fundus image for comparison with conventional retinal studies.
SDOCT of the posterior pole of 12 eyes (5 with neovascular age-related macular degeneration [AMD]; 7 with nonneovascular AMD) produced three-dimensional stacks of scans. Location of pathologic features was delineated with color markings in each scan before the stack was collapsed along the depth axis. This en face image contained retinal vessel shadowing and preserved color markings of delineated pathologic features relative to the vessel pattern and was superimposed onto conventional studies.
For patients with neovascular AMD, location and extent of choroidal neovascularization, macular edema, and subretinal fluid were visible on the two-dimensional summed images and, in some cases, involved sites not suspected with conventional imaging. For patients with nonneovascular AMD, the location of drusen and geographic atrophy were correlated with autofluorescence images. For one eye with drusen and three eyes with neovascular AMD, presence or extent of subretinal fluid identified by SDOCT was not visible using other imaging methods.
In this pilot AMD study, pathologic features within SDOCT scans were transferred into two-dimensional en face projections, enabling researchers to correlate lateral extent of pathologic features from SDOCT with conventional studies. This integration of SDOCT with other retinal studies is promising and will be useful to study the relationship between local OCT morphology and other parameters of retinal disease or function.
We delineated pathologic features within three-dimensional spectral domain optical coherence tomography volumes and projected marked sites of pathologic features onto clinically useful two-dimensional localization maps to be overlaid on conventional clinical images.
From the *Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA; the †Department of Ophthalmology, Poznan University of Medical Sciences, Poznan, Poland; and the ‡Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina, USA.
Supported by grants from the National Institutes of Health (EB000243 to J.A.I. and C.A.T.; and RR019769 to J.A.I. and B.A.B.), The Edward L. Grayson Retinal Research Fund (West Orange, NJ [to M.S.]), and a software donation from Bioptigen, Inc. (Research Triangle Park, NC).
M.T., C.A.T., and B.A.B. have a patent application pending related to this work. C.A.T. receives royalties through Duke University Patent Policy for other technology licensed by Duke to Alcon Laboratories, Inc. (Fort Worth, TX), and research funding per Duke University policies from Bioptigen, Inc. B.A.B. and J.A.I. have financial interests in Bioptigen, Inc.
Reprint requests: Cynthia A. Toth, MD, Duke University Eye Center, Box 3802, Erwin Road, Durham, NC 27710; e-mail: email@example.com