Enhanced depth imaging optical coherence tomography.

Imaging the choroid with conventional commercial spectral-domain optical coherence tomography (SD-OCT) has been difficult, mainly because of difficulty in signal transmission beyond the retinal pigment epithelium. A recent modification to the standard technique, termed enhanced depth imaging optical coherence tomography (EDI-OCT), was able to image the choroid with reasonable clarity using commercial SD-OCTs. The aim of this article was to review the technique, principle, recent findings, and possible future developments regarding EDI-OCT. A MEDLINE search on all published articles on EDI-OCT was performed up to December 2010. The principle behind EDI-OCT was discussed. Modification to the conventional technique in image acquisition was described and illustrated with figures. EDI-OCT findings in various retinal and choroidal diseases were discussed. Advantages and disadvantages were also discussed. EDI-OCT has proved to be a promising novel technique in imaging the choroid.