Inter-device variability of the Stratus optical coherence tomography.
OBJECTIVE
To assess inter-device measurement variability with the Stratus optical coherence tomography (OCT).


METHODS
Evaluation of diagnostic test technology.


METHODS
Eight eyes of eight healthy subjects were examined with four different Stratus machines in four medical centers during a period of five hours using fast retinal nerve fiber layer (RNFL) and fast macula protocols. Inter-device measurement variability and signal strength was assessed with standard deviation, coefficient of variance, and intraclass correlation coefficient (ICC). Spearman correlation coefficient was calculated between signal strength and thickness measurements.


RESULTS
Statistically significant differences were not found for all macular parameters and all but one RNFL parameter. Mean signal strengths obtained with the four Stratus machines were significantly different; the newer the machine, the stronger signal strength it produced. Some RNFL parameters were moderately and statistically significantly correlated with signal strength.


CONCLUSIONS
We did not observe statistically significant differences in any macular and all but one RNFL parameter between the four Stratus OCT machines. Signal strength was significantly different between the machines, and significantly correlated with some RNFL parameters. Inter-machine variability in RNFL measurements may have clinical significance. Signal strength should be included in the assessment of measurements obtained on different machines and in serial examinations with a single Stratus machine during patient follow-up.
Department of Ophthalmology, Assaf Harofe Medical Center, Zerifin, Israel. yaniv.barkana@yahoo.com
Yaniv
Y
Barkana
Zvia
Z
Burgansky-Eliash
Yariv
Y
Gerber
Shlomo
S
Melamed
Meira
M
Neudorfer
Isaac
I
Avni
Elisha
E
Bartov
Yair
Y
Morad
D000328:Adult; D003430:Cross-Sectional Studies; D003941:Diagnostic Techniques, Ophthalmological / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D009412:Nerve Fibers; D009898:Optic Disk / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000166:cytology*; D041623:Tomography, Optical Coherence / Q000592:standards* / Q000706:statistics & numerical data