Grayscale and proportion-corrected optical coherence tomography images

BACKGROUND AND OBJECTIVE: The commercially available optical coherence tomo graphy (OCT) scanner displays images in a pre-set window regardless of the projected scan length on the retinal surface. The aim of this study was to demonstrate the true dimensions of proportion-corrected OCT images and the additional information present in grayscale images. MATERIALS AND METHODS: OCT raw data were exported to an IBM-compatible PC a nd processed to show grayscale and proportion-corrected images using an aut omated software of our own design. RESULTS: Eyes with cystoid macular edema and retinal pigment detachment wer e analyzed. Grayscale images showed a finer gradation of signal reflectance , Scan lengths of 2, 4, 6, and 8 mm on the retinal surface showed different qualitative appearances using proportion-corrected software from the print ed or on-screen images. CONCLUSIONS: Grayscale OCT images can be used to demonstrate additional inf ormation not present in false-color images. The disparity between the stand ard OCT image format and proportion-corrected images emphasizes the need fo r quantitative rather than qualitative evaluation of retinal dimensions and internal reflectance.