Articoli Scientifici di Oftalmologia
Argomento : 2
Comparison of Fourier-Domain ad Time-Domain Optical Coherence Tomography in the Measurement of Thinnest Corneal Thickness in Keratoconu
Scarica tutto l'articolo
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-subjects tandard deviation (𝑆(𝑤)), coefficient of variation (CV(𝑤)), and ICC.
Results.
The TCT value of normal corneas was higher by RTVue-OCT (530.4±19.7𝜇m) than Visante-OCT (521.5±18.3𝜇m)(𝑝 < 0.001).
For keratoconus eyes, the TCT was 425.0 ±58.2𝜇m and 424.4±55.7𝜇m (differencebeing0.6±10.2𝜇m,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 indetermining the TCT inallsubjects (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 intraobser verreliability.
The existence of systematic differences suggested that the two instruments cannot be used interchangeably.
