Schuman J S, Pedut-Kloizman T, Hertzmark E, Hee M R, Wilkins J R, Coker J G, Puliafito C A, Fujimoto J G, Swanson E A
New England Eye Center, Tufts University School of Medicine, Boston, MA 02111, USA.
Ophthalmology. 1996 Nov;103(11):1889-98. doi: 10.1016/s0161-6420(96)30410-7.
Optical coherence tomography (OCT) is a new technology that uses near-infrared light in an interferometer to produce approximately 10-microns resolution cross-sectional images of the tissue of interest. The authors performed repeated quantitative assessment of nerve fiber layer thickness in individuals with normal and glaucomatous eyes, and they evaluated the reproducibility of these measurements.
The authors studied 21 eyes of 21 subjects by OCT. Each subject underwent five repetitions of a series of scans on five separate occasions within a 1-month period. Each series consisted of three circular scans around the optic nerve head (diameters, 2.9, 3.4, and 4.5 mm). Each series was performed separately using internal (fixation with same eye being studied) and external (fixation with contralateral eye) fixation techniques. The eye studied and the sequence of testing were assigned randomly.
Internal fixation (IF), in general, provides a slightly higher degree of reproducibility than external fixation (EF). Reproducibility was better in a given eye on a given visit than from visit to visit. Reproducibility as measured by intraclass correlation coefficients were as follows: circle diameter (CD), 2.9 mm, 0.51/0.57 (normal/glaucoma) (IF), 0.43/0.54 (EF); CD, 3.4 mm, 0.56/0.52 (IF), 0.43/0.61 (EF); CD, 4.5 mm, 0.53/0.43 (IF), 0.42/0.49 (EF).
Nerve fiber layer thickness can be reproducibly measured using OCT. Internal is superior to external fixation; each circle diameter tested provides adequate reproducibility.
光学相干断层扫描（OCT）是一项新技术，它在干涉仪中使用近红外光来生成感兴趣组织的约10微米分辨率的横截面图像。作者对正常眼和青光眼患者的神经纤维层厚度进行了重复定量评估，并评估了这些测量的可重复性。
作者通过OCT研究了21名受试者的21只眼睛。每位受试者在1个月内的5个不同时间对一系列扫描进行了5次重复。每个系列包括围绕视神经乳头的三次圆形扫描（直径分别为2.9、3.4和4.5毫米）。每个系列分别使用内固定（用被研究的同一只眼睛注视）和外固定（用对侧眼睛注视）技术进行。被研究的眼睛和测试顺序是随机分配的。
一般来说，内固定（IF）比外固定（EF）提供的可重复性略高。在给定的一次就诊中，给定眼睛的可重复性比不同就诊之间的更好。通过组内相关系数测量的可重复性如下：圆直径（CD）为2.9毫米时，0.51/0.57（正常/青光眼）（IF），0.43/0.54（EF）；CD为3.4毫米时，0.56/0.52（IF），0.43/0.61（EF）；CD为4.5毫米时，0.53/0.43（IF），0.42/0.49（EF）。
使用OCT可以可重复地测量神经纤维层厚度。内固定优于外固定；所测试的每个圆直径都提供了足够的可重复性。
