Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography: A Variability and Diagnostic Performance Study
Received 3 October 2008; received in revised form 3 April 2009; accepted 3 April 2009. published online 22 May 2009.
Objective
To evaluate and compare the retinal nerve fiber layer (RNFL) measurement variability, diagnostic sensitivity and specificity for glaucoma detection, and strength of the structure–function association obtained with a spectral-domain optical coherence tomography (OCT) device (Cirrus HD-OCT; Carl Zeiss Meditec, Inc., Dublin, CA) and a time-domain OCT device (Stratus OCT; Carl Zeiss Meditec, Inc.).
Design
Prospective, cross-sectional study.
Participants
Ninety-seven normal subjects and 83 glaucoma patients.
Methods
One eye from each subject was imaged with Cirrus HD-OCT and Stratus OCT. Sixteen and 31 normal eyes were selected randomly to evaluate intravisit repeatability and intervisit reproducibility, respectively. The agreement of RNFL measurements was evaluated with Bland–Altman plots. The diagnostic sensitivity and specificity was examined with the area under the receiver operating characteristic curve (AUC). The association between average RNFL thickness and visual field sensitivity was evaluated with a second-order regression model.
Main Outcome Measures
Retinal nerve fiber layer measurement variability, AUC, and coefficient of determination (R2).
Results
The intravisit repeatability of Cirrus HD-OCT ranged between 5.12 and 15.02 μm, and the intervisit reproducibility ranged between 4.31 and 22.01 μm. The intervisit variabilities of sectoral and average RNFL thicknesses were lower in Cirrus HD-OCT compared with Stratus OCT with significant differences at 1, 3, 4, and 8 to 11 o'clock (P≤0.021). There were proportional biases of RNFL measurements between the 2 OCT devices. The difference of RNFL thicknesses increased with the means. The average (AUC, 0.962 for Cirrus HD-OCT and 0.956 Stratus OCT), superior (AUC, 0.963 and 0.950, respectively), and inferior (AUC, 0.949 and 0.931, respectively) RNFL thicknesses demonstrated the greatest AUCs in both OCT devices with no significant difference detected between the respective measurements (P≥0.120). The strength of the structure–function association was comparable between Cirrus HD-OCT (R2 = 0.580) and Stratus OCT devices (R2 = 0.623; P = 0.918).
Conclusions
Although the diagnostic performance and the strength of the structure–function association were comparable between Cirrus HD-OCT and Stratus OCT RNFL measurements, Cirrus HD-OCT demonstrated lower measurement variability compared with Stratus OCT with significant differences at 1, 3, 4, and 8 to 11 o'clock. The poor agreement was likely related to the different inherent characteristics of the 2 OCT systems.
Financial Disclosure(s)
Proprietary or commercial disclosure may be found after the references.
Available online: May 22, 2009.
1Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
2Hamilton Glaucoma Center, University of California, San Diego, La Jolla, California
3The STU/CUHK Joint Shantou International Eye Centre (JSIEC), Shantou University Medical College, People's Republic of China
4Shenzhen Eye Hospital of Jinan University, Shenzhen, People's Republic of China
Correspondence: Christopher Kai-shun Leung, MD, MBChB, Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong
Manuscript no. 2008-1184.
Financial Disclosure(s): The author(s) have made the following disclosure(s):
Christopher Kai-shun Leung - Speaker Honorarium - Carl Zeiss Meditec, Heidelberg Engineering, Topcon; - Research Support - Carl Ziess Meditec.
Robert N. Weinreb - Consultant - Carl Zeiss Meditec; Research Support - Carl Zeiss Meditec, Heidelberg Engineering, and Optovue.
Supported by the Chinese University of Hong Kong, Hong Kong, People's Republic of China (Direct Grant: 07-08).
ABSTRACT