Macular Degeneration: Lujan BJ

Lujan BJ, Rosenfeld PJ, Gregori G, Wang F, Knighton RW, Feuer WJ, Puliafito CA. · Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA. · Ophthalmic Surg Lasers Imaging. · Pubmed #19320296 No free full text.

Abstract: BACKGROUND AND OBJECTIVE: To compare images of geographic atrophy (GA) obtained using spectral domain optical coherence tomography (SD-OCT) with images obtained using fundus autofluorescence (FAF). PATIENTS AND METHODS: Five eyes from patients with dry AMD were imaged using SD-OCT and FAF, and the size and shape of the GA were compared. RESULTS: GA appears bright on SD-OCT compared with the surrounding areas with an intact retinal pigment epithelium because of increased reflectivity from the underlying choroid. SD-OCT and FAF both identified GA reproducibly, and measurement of the area of GA is comparable between the two methods with a mean difference of 2.7% of the total area. CONCLUSION: SD-OCT can identify and quantitate areas of GA. The size and shape of these areas correlate well to the areas of GA seen on autofluorescence images; however, SD-OCT imaging also provides important cross-sectional anatomic information.

Lujan BJ, Wang F, Gregori G, Rosenfeld PJ, Knighton RW, Puliafito CA, Danis RP, Hubbard LD, Chang RT, Budenz DL, Seider MI, Knight O. · Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA. · Ophthalmic Surg Lasers Imaging. · Pubmed #18777875 No free full text.

Abstract: BACKGROUND AND OBJECTIVE: Measurements performed on fundus images using current software are not accurate. Accurate measurements can be obtained only by calibrating a fundus camera using measurements between fixed retinal landmarks, such as the dimensions of the optic nerve, or by relying on a calibrated model eye provided by a reading center. However, calibrated spectral domain OCT (SD-OCT) could offer a convenient alternative method for the calibration of any fundus image. PATIENTS AND METHODS: The ability to measure exact distances on SD-OCT fundus images was tested by measuring the distance between the center of the fovea and the optic nerve. Calibrated SD-OCT scans measuring 6 X 6 X 2 mm centered on the fovea and the optic nerve were analyzed in 50 healthy right eyes. The foveal center was identified using cross-sectional SD-OCT images, and the center of the optic nerve was identified manually. The SD-OCT scans were registered to each other, and the distances between the center of the optic nerve and fovea were calculated. The overlay of these SD-OCT fundus images on photographic fundus images was performed. RESULTS: Any image of the fundus could be calibrated by overlaying the SD-OCT fundus image, and the measurements were consistent with previously defined calibration methods. The mean distance between the center of the fovea and the center of the optic nerve was 4.32 +/-0.32 mm. The line from the center of the optic nerve to the foveal center had a mean declination of 7.67 +/- 3.88 degrees. Mean horizontal displacement and vertical displacement were 4.27 +/- 0.29 mm and 0.58 +/- 0.29 mm, respectively. CONCLUSIONS: The overlay of the SD-OCT fundus image provides a convenient method for calibrating any image of the fundus. This approach should provide a uniform standard when comparing images from different devices and from different reading centers.