Abstract
Purpose:
to evaluate 100 degrees horizontal and vertical vitreoretinal interface from the macula into periphery using Spectral Domain Optical Coherence Tomography (SD-OCT) Enhanced Vitreous Imaging (EVI) montage images of three different 55 degrees B-scan obtained on the same line.
Methods:
Observational case series of 25 eyes. Consecutive patients from Vitreoretinal Clinic of Luigi Sacco Hospital were scanned using a new widefield OCT module of Heidelberg Spectralis (Heidelberg Spectralis, Heidelberg Engineering, Germany software version 6.0.9) that allows to extend the field of view of OCT cross-sectional imaging to 55 degrees (approx. 16.5mm).<br /> Each eye was scanned in 6 different locations, 3 horizontal B-scan (central, temporal and nasal) and 3 vertical B-scan (central superior and inferior). In order to match the three different scans we moved the internal fixation light. A montage technique (Photoshop Elements version 11; Adobe, San Jose, CA) has been used to generate horizzontal and vertical SD-OCT images approximately 100 degrees wide spanning through the fovea.<br /> Retinal layers were positioned inferiorly on the image screen to achieve adequate imaging resolution of vitreoretinal interface, furthermore as described in literature as EVI technique we added circa 2 diopters to the OCT focus and set the ART to 100 frames.
Results:
All 50 montage images were created and all had good qualit. In 3 eyes vitreous was not visible in both horizontal and vertical montage images (1 full-thickness macular hole and 2 pucker). In 1 eye with posterior vitreous detachment vitreous was well visible in both montage images but not showing any area of persistent attachment at the periphery. In the remaining 21 eyes cortical vitreous was well discernible with adhesion areas at the posterior pole and/or at the periphery (14 incomplete posterior vitreous detachment, 4 vitreous macular traction, 3 vitreomacular adhesion).
Conclusions:
Ultra widefield OCT with EVI technique can clearly show detailed information of peripheral vitreoretinal interface, including shape and extension of shallow vitreous detachments. Moreover vertical EVI ultra widefield OCT apparently gives better imaging quality of vitreous structure than the horizontal ones. OCT’s companies should improve their software including an automatic tool to create montage images.