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* BACKGROUND AND OBJECTIVE: Spectral domain optical coherence tomography (SD-OCT) allows three-dimensional imaging of the optic disc. The objective of this study was to compare optic disc and cup margins between fundus photographs and SD-OCT.
* PATIENTS AND METHODS: Eighteen eyes with glaucoma were examined by a custom-built SD-OCT. OCT fundus images were used to register fundus photographs and SD-OCT volume.
* RESULTS: Disc margins on fundus photographs corresponded to termination of the highly reflective straight line that represented the retinal pigment epithelium (RPE) or the highly reflective curved line that connected to the RPE on the OCT B-scan images at 99.3% of the positions along the disc edges. Cup margins on fundus photographs corresponded at 73.6% of the positions to the interior border of the hyporeflective regions on the OCT fundus images.
* CONCLUSIONS: Excellent to fair correspondence in the determination of disc and cup margins between fundus photographs and SD-OCT images was shown.
[Ophthalmic Surg Lasers Imaging 2009;40:255-263.]
INTRODUCTION
Detection of glaucomatous changes in the optic nerve head is important for the early diagnosis and management of glaucoma. Topographic analysis of the optic nerve head has been achieved by optical imaging instruments, such as the Heidelberg Retina Tomograph (HRT), and by optical coherence tomography (OCT). Using these diagnostic instruments, determination of the optic disc margin and definition of the cup margin is fundamental to providing accurate and reproducible topographic disc parameters.
The HRT is based on confocal principles and shows the three-dimensional surface topography of the optic nerve head, which allows for quantitative analysis of glaucomatous changes of the optic nerve head. Although the HRT and HRT2 (Heidelberg Engineering GmbH, Dossenheim, Germany) are a well-defined method for optic nerve head analysis, they require manual determination of the disc margin to define a reference plane that is then used to calculate the cup margin, although the Glaucoma Probability Score in the HRT3 allows for assessment of the optic nerve head independent of the contour line traced by the examiner. 1-3 Because accurate determination of the disc margin depends on the skill of the operator, calculation of the cup margin is also affected by the skill of the operator.4 In addition, accuracy of the disc margin cannot be verified in cross-sectional images because...