PurposeTo evaluate the efficacy of the features and capabilities of the Cirrus^tmHD-OCT, a spectral domain optical coherence tomography instrument (Carl Zeiss Meditec, Dublin, CA) for detecting glaucoma.MethodsCirrus HD-OCT provides glaucoma acquisition and analysis. Review of existing data on repeatability and distribution of normals indicates that the performance for glaucoma detection should be similar to or better than time domain OCT.ResultsCirrus HD-OCT provides RNFL thickness parameters similar to those provided by Stratus OCT. The thickness parameters do not map identically to Stratus and should be treated independently. The overall dynamic range of normals (standard deviation of the population of normals of 9.4μm for average thickness) is similar to Stratus, and the repeatability is better (1.35μm reproducibility, or 1.6% coefficient of variability for overall average thickness).ConclusionBecause Stratus OCT and Cirrus HD-OCT have similar dynamic ranges and Cirrus has better repeatability, the Cirrus HD-OCT is expected to have performance in detecting glaucoma that is as good as or better than Stratus OCT.