Figure 1.

Comparison of conventional OCT with AO-OCT. Horizontal wide-field Spectralis B-scan centered on the fovea of one of the study's subjects (left). Image is displayed as the instrument displays it, in logarithmic scale. Red and blue boxes indicate locations, 2.0° nasal and 5.0° nasal, used for AO-OCT imaging. Magnified view (near right) of a portion of the Spectralis image containing outer retinal layers at 5.0° nasal, in linear scale. Corresponding AO-OCT image (far right) from the same location in the same subject, also shown in linear scale. In both inset images, the outer retinal layers 1 through 4 are labeled. Bands 1, 3, and 4 correspond to putative ELM, COST, and RPE, respectively. The controversy surrounding the origin of band 2 is the subject of the present investigation. For the Spectralis, linearizing required use of the instrument's reported dynamic range (43 dB). All of the qualitative and quantitative observations presented in this paper were performed using linear intensity for both Spectralis and AO-OCT images. The Spectralis was operated in ‘ART' mode, and the resulting image is an average of 100 frames. The AO-OCT image shown is a single frame. In magnified views, scale bars (white) indicate 50 μm in lateral and axial dimensions.