Department of Ophthalmology, College of Medicine, University of Florida, Jacksonville, FL 32209, USA.
Invest Ophthalmol Vis Sci. 2010 May;51(5):2644-7. doi: 10.1167/iovs.09-4774. Epub 2009 Dec 10.
Spectral-domain optical coherence tomography (SD-OCT) is an advancement over time-domain OCT (TD-OCT) in the imaging of retinal disorders. Retinal thickness measured by SD-OCT differs from that measured by TD-OCT because the delineation of the outer boundary of the retina differs in the two instruments. The present study aims to evaluate this difference by comparing macular thickness, as obtained by Stratus and Spectralis OCT, in subjects without any known retinal disease.
Thirty-six subjects with no history of retinal disease and with normal vision and normal intraocular pressure were enrolled in the study. Both Stratus and Spectralis OCT scanning were performed by the same operator on all subjects in one eye. Central point thickness (CPT) and retinal thickness in nine ETDRS subfields, including central subfield (CSF), were measured. Student's t-test was used to determine statistical significance.
Mean CPT, as measured by the Stratus and Spectralis OCT, was 166.9 +/- 20.9 microm and 225.1 +/- 17.1 microm (P < 0.0001), and mean CSF was 202.3 +/- 19.6 microm and 271.4 +/- 19.6 microm (P < 0.0001), respectively. Although the mean difference in CSF thickness was 69.1 microm, it ranged from 61.9 to 74 microm in the other eight ETDRS subfields.
An increased measurement in retinal thickness of approximately 65 to 70 microm, as measured by Spectralis OCT compared with Stratus OCT, is consistent with the extent of axial retinal thickness measured by the two instruments. This increased measurement corresponds to the inclusion of the outer segment-RPE-Bruch's membrane complex by Spectralis OCT, which is relevant to studies using the newer SD-OCT for assessment of retinal thickness.
相较于时域光学相干断层扫描（TD-OCT），谱域光学相干断层扫描（SD-OCT）在视网膜疾病成像方面有了显著的进步。SD-OCT 测量的视网膜厚度与 TD-OCT 不同，因为两种仪器中外层视网膜边界的界定不同。本研究旨在通过比较 Stratus 和 Spectralis OCT 获得的黄斑厚度，评估这种差异，这些患者均无已知的视网膜疾病。
本研究共纳入 36 名无眼部疾病史、视力和眼压正常的患者。由同一位操作者对所有患者的每只眼分别进行 Stratus 和 Spectralis OCT 扫描。测量中央点厚度（CPT）和包括中心凹在内的 9 个 ETDRS 亚区的视网膜厚度。采用 Student's t 检验进行统计学分析。
Stratus 和 Spectralis OCT 分别测量的平均 CPT 为 166.9 ± 20.9μm 和 225.1 ± 17.1μm（P < 0.0001），平均 CSF 分别为 202.3 ± 19.6μm 和 271.4 ± 19.6μm（P < 0.0001）。虽然 CSF 厚度的平均差值为 69.1μm，但在其他 8 个 ETDRS 亚区的差值范围为 61.9μm 至 74μm。
相较于 Stratus OCT，Spectralis OCT 测量的视网膜厚度增加了约 65μm 至 70μm，这与两种仪器测量的轴向视网膜厚度一致。这种增加的测量对应 Spectralis OCT 包含的外节-视网膜色素上皮-脉络膜复合层，这与使用新型 SD-OCT 评估视网膜厚度的研究相关。
