Determination of optical scattering properties of highly-scattering media in optical coherence tomography images

Purpose: The aim of this study was to evaluate the correlations between fundus autofluorescence and morphologic parameters as well as visual function in patients with diabetic macular oedema treated with intravitreal ziv-aflibercept. Methods: A total of 34 eyes of 20 patients with untreated diabetic macular oedema received an intravitreal injection of ziv-aflibercept at baseline, and 1 and 2 months later. The baseline, 1-month, and two-month best corrected visual acuity determination, contrast sensitivity, spectral domain optical coherence tomography, mean central macular thickness, mean macular cube volume, mean macular cube average thickness, and fundus autofluorescence (decreased, normal, or increased; and single or multiple spots) were measured. Correlation analysis with a determination of Spearman’s rank correlation coefficient, regression analysis, agreement between investigators, and Friedman’s test were used for statistical analyses. Results: A direct correlation was observed between baseline fundus autofluorescence and macular cube average thickness at 1 month (r = 0.51, p = 0.020) and between fundus autofluorescence at 1 month and baseline macular cube average thickness (r = 0.50, p = 0.021). Regression analysis showed a coefficient of determination of 0.29 (p = 0.016) between baseline fundus autofluorescence and macular cube average thickness at 1 month. Conclusion: In patients with diabetic macular oedema, the pretreatment baseline degree of foveal fundus autofluorescence might be helpful in predicting macular cube average thickness in patients undergoing treatment with intravitreal ziv-aflibercept in the short term.

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

Journal of Ophthalmology ◽

10.1155/2015/402925 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Chunxiao Wang ◽

Xueying Xia ◽

Bishan Tian ◽

Shiyou Zhou

Keyword(s):

Optical Coherence Tomography ◽

Time Domain ◽

Pearson Correlation ◽

Corneal Thickness ◽

Intraclass Correlation ◽

Fourier Domain ◽

Optical Coherence ◽

Highly Correlated ◽

Time Domain Oct

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.

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