scholarly journals Comparison of Fourier-Domain and Time-Domain Optical Coherence Tomography in the Measurement of Thinnest Corneal Thickness in Keratoconus

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Chunxiao Wang ◽  
Xueying Xia ◽  
Bishan Tian ◽  
Shiyou Zhou

Objective. To compare fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT (TD-OCT) in the determination of thinnest corneal thickness (TCT).Methods. This study included 55 keratoconus patients and 50 healthy volunteers. The RTVue-OCT (FD-OCT) and Visante-OCT (TD-OCT) were used for the measurement of the TCT. Three consecutive scans were performed. The comparison and agreement between the two modalities were analyzed by pairedt-test, the Pearson correlation, intraclass correlation coefficient (ICC), and Bland-Altman plots. intraobserver repeatability was analyzed by the intraobserver within-subject standard deviation (S(w)), coefficient of variation (CV(w)), and ICC.Results. The TCT value of normal corneas was higher by RTVue-OCT (530.4 ± 19.7 μm) than Visante-OCT (521.5 ± 18.3 μm) (p<0.001). For keratoconus eyes, the TCT was 425.0 ± 58.2 μm and 424.4 ± 55.7 μm (difference being 0.6 ± 10.2 μm,p=0.604). Strong correlation (r= 0.938∼0.985) (ICC = 0.915–0.984) was observed between the two OCTs, and each OCT exhibited excellent repeatability in determining the TCT in all subjects (ICC = 0.984–0.994).Conclusions. The values of TCT obtained from RTVue-OCT and Visante-OCT were highly correlated; however, the two values were different. Both OCT instruments exhibited good intraobserver reliability. The existence of systematic differences suggested that the two instruments cannot be used interchangeably.

2009 ◽  
Vol 148 (2) ◽  
pp. 282-290.e2 ◽  
Author(s):  
Gaurav Prakash ◽  
Amar Agarwal ◽  
Soosan Jacob ◽  
Dhivya Ashok Kumar ◽  
Athiya Agarwal ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sisi Chen ◽  
Rongrong Gao ◽  
Colm McAlinden ◽  
Junming Ye ◽  
Yiran Wang ◽  
...  

Purpose. To compare central corneal thickness (CCT), aqueous depth (AQD), and anterior chamber depth (ACD) measurements using the swept-source (CASIA SS-1000, Tomey, Japan) and time-domain (Visante, Carl Zeiss Meditec, USA) anterior segment optical coherence tomographers (OCT) in normal eyes. Methods. Sixty-eight eyes of 68 subjects were included. Three consecutive scans of each subject were obtained using both devices in a random order by one experienced operator. Standard deviation (Sw), coefficient of repeatability (CoR), coefficients of variation (CoV), and intraclass correlation coefficients (ICC) were used to evaluate the intraoperator repeatability. Agreement was assessed using the Bland–Altman plots and 95% limits of agreement (LoA). Results. All measurements of the swept-source OCT (SS-OCT) and time-domain OCT (TD-OCT) showed high repeatability with low CoR (CCT: 2.34 μm and 6.16 μm; AQD: 0.05 mm and 0.09 mm; ACD: 0.06 mm and 0.09 mm), low CoV (CCT: 0.16% and 0.42%; AQD: 0.61% and 0.97%; ACD: 0.53% and 0.83%), and high ICC (>0.98). The mean CCT with SS-OCT was slightly thicker than the results with TD-OCT (difference = 4.55 ± 2.62 μm, P<0.001). There was no statistically significant difference in AQD or ACD measurements between the two devices (0.01 ± 0.05 mm, P=0.111; 0.02 ± 0.05 mm, P=0.022, respectively). The 95% LoA between the SS-OCT and TD-OCT were −0.59 to 9.69 μm for CCT, −0.10 to 0.12 mm for AQD, and −0.09 to 0.12 mm for ACD. Conclusions. High levels of repeatability and agreement were found between the two devices for all three parameters, suggesting interchangeability. SS-OCT demonstrated superior repeatability compared with TD-OCT.


2009 ◽  
Vol 147 (1) ◽  
pp. 56-63.e2 ◽  
Author(s):  
Luciana V.F. Costa-Cunha ◽  
Leonardo P. Cunha ◽  
Roberto F.S. Malta ◽  
Mário L.R. Monteiro

2011 ◽  
Author(s):  
Shahab Chitchian ◽  
Gwen Lagoda ◽  
Arthur Burnett ◽  
Nathaniel M. Fried

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 131
Author(s):  
Aymen Rashid ◽  
Yasir J Sepah ◽  
Roomasa Channa ◽  
Elham Hatef ◽  
Matthew Shulman ◽  
...  

Purpose: To evaluate the reproducibility and reliability of Optical Coherence Tomography scans (OCT) obtained using the Time Domain (TD-OCT) StratusTM OCT, and the Spectral Domain (SD-OCT) SpectralisTM and CirrusTM OCT devices before and after manual correction in eyes with either Neovascular (NV-AMD) or Non-Neovascular (NNV-AMD) Age-related Macular Degeneration.Methods: We conducted a prospective observational study of 36 patients (50 eyes) with NV-AMD or NNV-AMD at a university-based retina practice. OCT scans were taken simultaneously using one TD-OCT and two SD-OCT devices. Macular thickness measurements were assessed before and after correction of the OCT algorithm by constructing Bland-Altman plots for agreement and calculating intraclass correlation coefficients (ICCs) and coefficients of repeatability (COR) to evaluate intraclass repeatability.Results: The Spectralis device had the highest number of images needing manual correction. All machines had high ICCs, with Spectralis having the highest. Bland-Altman plots indicated that there was low agreement between both Cirrus™ and Stratus™ and Spectralis™ and Stratus™, while there was good agreement between the Cirrus™ and Spectralis™ devices. The CORs were lowest for SpectralisTM and similar with each other and had higher values for CirrusTM and StratusTM. Agreement, CORs, and ICCs generally improved after manual correction, but only minimally.  Conclusion: Agreement is low between devices, except between both SD-OCT machines. Manual correction tends to improve results.


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