Purchase this article with an account.
Mahnaz Shahidi, Justin M. Wanek, Ruth Zelkha; Enface Imaging of Photoreceptor Cell Integrity. Invest. Ophthalmol. Vis. Sci. 2011;52(14):2877.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The brightness of the photoreceptor cell inner segment and outer segment (ISOS) junction, as visualized by spectral domain optical coherence tomography (SDOCT), has been shown to be related to visual function. The purpose of the study is to report an image segmentation and reconstruction method for enface imaging of the photoreceptor ISOS junction.
SDOCT images were acquired in 6 normal subjects (44 ± 11 years). A customized high density SDOCT volume scan was acquired consisting of 145 horizontal raster B-scans, separated by 31 microns on the retina. SDOCT B-scan images were automatically segmented to identify the ISOS junction and the intensity data along the ISOS junction was extracted. Data obtained from the raster B-scans were combined to generate an ISOS enface image in a 4.4 mm x 4.4 mm retinal area, centered on the fovea. An infrared (IR) scanning laser ophthalmoscope (SLO) image was acquired and cropped to provide a field of view similar to the ISOS enface image for comparative studies.
Intensity values observed on the ISOS enface image corresponded to brightness levels of the photoreceptor ISOS junction. ISOS enface images generated in normal subjects displayed uniform intensities, indicative of a relatively constant light reflectance from the ISOS junction and normal photoreceptor cell integrity. In some normal subjects, the ISOS enface image intensity at the foveal center was slightly lower as compared to intensities in parafoveal areas. Due to the absorption of light by blood, the retinal vasculature was clearly visualized in the ISOS enface images, matching the vascular network patterns observed in IR SLO images. In one normal subject, a dark focal spot was detected in the ISOS enface image, corresponding to a discontinuity in the ISOS junction on the B-scan at a location superonasal to the fovea. The ISOS enface images had higher contrast as compared to IR SLO images.
The ability to detect intensity abnormalities in the ISOS enface image is useful for evaluating the integrity of the photoreceptor cells in the course of disease progression and therapeutic intervention.
This PDF is available to Subscribers Only