Diagnostic Ability of Spectral-domain Versus Time-domain Optical Coherence Tomography in Preperimetric Glaucoma

PURPOSE: To evaluate and compare the diagnostic abilities of the speckle noise-reduced spectral-domain optical coherence tomography (SD-OCT; Spectralis OCT) and time-domain optical coherence tomography (TD-OCT; Stratus OCT) to detect localized retinal nerve fiber layer (RNFL) defects in patients with preperimetric open-angle glaucoma. METHODS: Thirty-five eyes of 35 preperimetric glaucoma patients with localized RNFL defects and 72 normal control eyes were scanned using SD-OCT and TD-OCT. Areas under the receiver-operating characteristic curves (AUROCs), and the sensitivity and specificity for detecting localized RNFL defects based on the internal normative database of each device were calculated and compared. RESULTS: The AUROC for the best parameter from SD-OCT (inferotemporal sector, AUROC=0.940) was significantly higher than that of TD-OCT (7 o'clock sector, AUROC=0.881; P=0.009). The sensitivity of the SD-OCT parameters ranged from 18.9% to 83.8% and that of the TD-OCT parameters ranged from 5.4% to 54.1%, with the criterion of abnormal at the 5% level. The highest sensitivity of the SD-OCT was found with the temporal-superior-nasal-inferior-temporal thickness graph abnormal at the 5% level, which had a specificity of 90.3%. On the basis of temporal-superior-nasal-inferior-temporal thickness graphs, SD-OCT was more sensitive (P=0.001) for detection of preperimetric RNFL defects than TD-OCT at a comparable specificity (P=0.227). CONCLUSIONS: Speckle noise-reduced SD-OCT is better able to detect preperimetric localized RNFL defect(s) than TD-OCT.