Spectral-domain optical coherence tomography for the diagnosis and follow-up of glaucoma

As spectral-domain optical coherence tomography (SD-OCT) progressively replaces time-domain OCT (TD-OCT) in the clinical and research setting, several commercially available instruments and new software upgrades for glaucoma diagnosis and progression analysis have been developed. Over the last year, several studies have been performed to assess the diagnostic performance of most of these instruments necessitating a review of their findings.

When compared with the measurements provided by TD-OCT, the conventional peripapillary circular scans by SD-OCT, which aim to measure the retinal nerve fiber layer (RNFL) thickness, show higher repeatability and similar diagnostic sensitivity. New software capabilities, such as the RNFL deviation map of Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA) or the macular Ganglion Cell Complex scan of RTVue (Optovue, Fremont, CA), provide complementary information that enhances our ability to discriminate between healthy and glaucomatous eyes.

SD-OCT-based instruments represent a technological advancement in the diagnosis of glaucoma. Improved repeatability will facilitate more reliable follow-up and progression analysis.