Diagnostic Ability of Fourier-Domain vs Time-Domain Optical Coherence Tomography for Glaucoma Detection

Purpose: To compare retinal nerve fiber layer (RNFL) thickness assessments and the discriminating ability of Fourier-domain optical coherence tomography (FD-OCT) with that of time-domain optical coherence tomography (TD-OCT) for glaucoma detection. Design: Prospective, nonrandomized, observational cohort study. Methods: Normal and glaucomatous eyes underwent complete examination, standard automated perimetry, optic disc photography, TD-OCT (Stratus OCT; Carl Zeiss Meditec, Dublin, California, USA), and FD-OCT (RTVue; Optovue Inc, Fremont, California, USA). One eye per subject was enrolled. Two consecutive scans were acquired using a 3.46-mm diameter scan with TD-OCT and a 3.45-mm diameter scan with FD-OCT. For each of 5 RNFL parameters, the area under the receiver operator characteristic curve was calculated to compare the ability of FD-OCT and TD-OCT to discriminate between normal and glaucomatous eyes. Results: Fifty healthy persons (mean age, 65.3 ± 9.9 years) and 50 glaucoma patients (mean age, 67.7 ± 10.5 years) were enrolled. Average, superior, and inferior RNFL thickness measurements (in micrometers) were significantly (P < .01) greater with FD-OCT compared with TD-OCT in normal eyes (103.3 ± 12.6 vs 96.3 ± 10.7, 134.5 ± 18.6 vs 113.9 ± 16.3, and 129.7 ± 16.9 vs 125.5 ± 15.8, respectively) and glaucomatous eyes (P < .001; 77.6 ± 17.6 vs 70.4 ± 18.6, 108.0 ± 26.8 vs 86.8 ± 30.2, 82.2 ± 3.3 vs 73.5 ± 26.1, respectively). The area under the receiver operator characteristic curves for RNFL thickness were similar (P > .05) using FD-OCT (average, 0.88; superior, 0.80; inferior, 0.94) and TD-OCT (average, 0.87; superior, 0.79; inferior, 0.95). Conclusions: Cross-sectional peripapillary RNFL thickness measurements obtained using FD-OCT generated with the RTVue are greater than those obtained with TD-OCT and have similar diagnostic performance for glaucoma detection.