Purpose: To compare spectral domain optical coherence tomography (OCT) and fundus photography to identify localized retinal nerve fiber layer defects (RNFLD) in Chinese patients with early-to-medium advanced glaucoma. Methods: Thirty-nine patients (48 eyes) with localized RNFLDs by fundus photography and 48 age-matched control individuals were included into the study. The individuals underwent spectral domain OCT of the retinal nerve layer. In OCT, a localized RNFLD was defined as a dipping of the retinal nerve fiber layer thickness curve into the red-colored band of the graph, measured at a peripapillary circle with a diameter of 3.46mm. Results: In the 48 eyes of the study group, 63 localized RNFLDs were seen on the fundus photographs. On the OCTs, 58 of these 63 localized RNFLDs were detected, whereas 5 defects were not detected. Two localized RNFLDs seen on the OCTs were not found on the corresponding fundus photographs. The resulting sensitivity and specificity of OCT for detecting localized RNFLDs were 92% and 96%, respectively. The overall agreement rate between both methods was 94% (90/96), and the kappa value was 0.90 (P < 0.001). The results of both techniques correlated with each other for the determination of the location (Pearson correlation coefficient (r) = 0.99; P < 0.001) and the width of the localized RNFLDs (201 +/- 123 degrees vs. 207 +/- 115 degrees; r = 0.93; P < 0.001). Conclusions: Spectral domain OCT as compared with examiner-performed assessment of conventional fundus photographs is capable of detecting and measuring localized retinal nerve fiber layer defects with a relatively high diagnostic precision.