Grayscale and Proportion-Corrected Optical Coherence Tomography Images

Abstract

* BACKGROUND AND OBJECTIVE: The commercially available optical coherence tomography (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 and processed to show grayscale and proportion-corrected images using an automated software of our own design. * RESULTS: Eyes with cystoid macular edema and retinal pigment detachment were 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 printed or onscreen images. * CONCLUSIONS: Grayscale OCT images can be used to demonstrate additional information not present in false-color images. The disparity between the standard OCT image format and proportion-corrected images emphasizes the need for quantitative rather than qualitative evaluation of retinal dimensions and internal reflectance. [Ophthalmic Surg Lasers 2000;3 1:223-228]

Anterior Segment Optical Coherence Tomography in Phacotrabeculectomy

“…Different approaches have been developed to aid in the assessment of the anterior chamber angle (ACA) (4) . These approaches include the following:  Gonioscopy: is the current reference standard for evaluation of the anterior chamber angle .It has substantial inter-observer variability and relies on subjective assessment of ACA findings (5) .  Anterior segment Optical Coherence Tomography (AS-OCT) is a noninvasive, noncontact, in vivo imaging technique based on low-coherence interferometry (6) Anterior segment OCT provide high-resolution cross sectional images of the anterior of the eye (7) .…”