AUG 13, 2008
Comprehensive Ophthalmology, Retina/Vitreous
Following its original description by Huang and workers in 1991, optical coherence tomography (OCT) has steadily evolved into an integral element in the diagnosis and management of patients with posterior segment disease.1-4 OCT presented 2 significant advances over existing fundus imaging modalities:
- Cross-sectional imaging of the retina morphology
- Quantification of the effects of disease in the form of retinal thickness maps5
This original OCT technology, time-domain OCT (TD-OCT), was hindered by its relatively slow scanning speed, which limited the amount of retina that could be sampled during a scan acquisition and allowed eye movements to interfere with measurements in patients with unstable fixation. A recent advance in OCT technology, spectral-domain OCT (SD-OCT), has significantly increased scanning speeds (more than 100 fold in some cases) and has been touted as a dramatic advance in retinal imaging. Although SD-OCT instruments have been shown to provide spectacular 3-dimensional depictions of the retinal morphology, their clinical value has not been firmly established. This article reviews the advantages and limitations of SD-OCT technology and explores the potential clinical benefits of these instruments.