Published online May 12, 2015. doi: 10.5318/wjo.v5.i2.86
Peer-review started: August 17, 2014
First decision: October 14, 2014
Revised: February 9, 2015
Accepted: April 1, 2015
Article in press: April 7, 2015
Published online: May 12, 2015
AIM: To review the use of spectral domain optical coherence tomography (SD-OCT) for macular retinal ganglion cells (RGC) and ganglion cell complex (GCC) measurement in glaucoma assessment, specifically for early detection and detection of disease progression.
METHODS: A systematic review was performed by searching PubMed, Medline, and Web of Science for articles published in English through July 2014 describing the various macular SD-OCT scanning strategies developed for glaucoma assessment. The review focused on papers evaluating the use of macular RGC/GCC SD-OCT to detect early glaucoma and its progression. The search included keywords corresponding to the index test (macular ganglion cell/RGC/GCC/Spectral domain OCT), the target condition (glaucoma), and diagnostic performance. The RGC/GCC SD-OCT scanning strategies used to assess glaucoma of most commonly used SD-OCT instruments were described and compared. These included the Cirrus high definition-OCT (Carl Zeiss Meditec, Inc., Dublin, CA, United States), RTVue (Optovue, Inc., Fremont, CA, United States), Spectralis (Heidelberg Engineering, Heidelberg, Germany) and the 3D OCT 2000 (Topcon Corporation, Tokyo, Japan). Studies focusing on the ability of RGC/GCC SD-OCT to detect early glaucomatous damage and on the correlation between glaucomatous progression and RGC/GCC measurement by SD-OCT were reviewed.
RESULTS: According to the literature, macular RGC/GCC SD-OCT has high diagnostic power of preperimetric glaucoma, reliable discrimination ability to differentiate between healthy eyes and glaucomatous eyes, with good correlation with visual filed damage. The current data suggests that it may serve as a sensitive detection tool for glaucomatous structural progression even with mild functional progression as the rate of change of RGC/GCC thickness was found to be significantly higher in progressing than in stable eyes. Glaucoma assessment with RGC/GCC SD-OCT was comparable with and sometimes better than circumpapillary retinal nerve fiber layer thickness measurement.
CONCLUSION: An increasing body of evidence supports using macular RGC/GCC thickness as an indicator for early glaucoma. This might be a useful tool for monitoring disease progression.
Core tip: Glaucoma is an optic neuropathy characterized by structural changes followed by functional deficits. Diagnosing early signs of the disease and detecting its progression are challenging. This review focuses on the most common macular retinal ganglion cells/ganglion cell complex spectral domain optical coherence tomography (SD-OCT) scanning strategies developed for glaucoma assessment (Cirrus high definition-OCT, RTVue, Spectralis and 3D OCT 2000) described in the literature published through July 2014; specifically, studies that assessed the ability to diagnose early glaucoma and glaucoma progression. The findings highlight the central role of macular SD-OCT in identifying subjects with early and progressive anatomical and functional glaucomatous damage.