Choroidal Imaging Using Spectral-Domain Optical Coherence Tomography

Abstract

Background A structurally and functionally normal choroidal vasculature is essential for retinal function. Therefore, a precise clinical understanding of choroidal morphology should be important for understanding many retinal and choroidal diseases. Methods PUBMED (http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed) was used for most of the literature search for this article. The criterion for inclusion of an article in the references for this review was that it included materials about both the clinical and the basic properties of choroidal imaging using spectral-domain optical coherence tomography. Results Recent reports show successful examination and accurate measurement of choroidal thickness in normal and pathologic states using spectral-domain optical coherence tomography systems. This review focuses on the principles of the new technology that make choroidal imaging using optical coherence tomography possible and on the changes that subsequently have been documented to occur in the choroid in various diseases. Additionally, it outlines future directions in choroidal imaging. Conclusion Optical coherence tomography is now proven to be an effective noninvasive tool to evaluate the choroid and to detect choroidal changes in pathologic states. Additionally, choroidal evaluation using optical coherence tomography can be used as a parameter for diagnosis and follow-up.

Influence of choroidal thickness on subfoveal choroidal thickness measurement repeatability using enhanced depth imaging optical coherence tomography

“…The inner sclera was designated as the outermost hyperreflective chorio-scleral interface (CSI). 13 When the CSI was not visible on the thick choroid, the outermost hyporeflective line in the sclera was measured. 7 Since a large choroidal vessel, which was immediately in front of the sclera, is usually accompanied by an invisible CSI, the outermost choroidal vascular hyporeflective line formed a boundary.…”

Imaging of retinal and choroidal vascular tumours

“…17 The introduction of the high-resolution SD-OCT represents a major advance. 13,17,18 More scans with an axial resolution up to 5 mm are obtained more rapidly, also covering a larger area of the fundus. 13,18 Individual retinal layers up to the junction of the photoreceptor inner and outer segments can now be visualized.…”

“…13,17,18 More scans with an axial resolution up to 5 mm are obtained more rapidly, also covering a larger area of the fundus. 13,18 Individual retinal layers up to the junction of the photoreceptor inner and outer segments can now be visualized. 13 With vascular tumours, SD-OCT scans are mainly used for the detection and quantification of macular changes.…”

“…18 By pushing the OCT objective lens closer to the eye, an inverted image with higher resolution of the choroid can be obtained. 22 This 'enhanced depth imaging' may be useful in measuring and characterizing lesions o1 mm thick that are too thin to be measured with conventional ultrasonography.…”

“…SD-OCT has only a minor role in the differential diagnosis of vascular tumours, as this technique is useful only for the examination of posterior lesions and images only the superficial 1 mm of the retina and choroid. 18,19 Modern SD-OCT scanners also enable 3D reconstruction of retinal and superficial choroidal tumours. 17,20 With new montage techniques, an area of 50 1 Â 35 1 can be analysed.…”