Abstract
Purpose: :
To evaluate the influence of the eyetracking-based follow-up (EBF) function in the reproducibility of the peripapillary retinal nerve fiber layer (RNFL) thickness measurements in healthy subjects obtained with Fourier-domain optical coherence tomography (Fd-OCT).
Methods: :
Thirty healthy subjects (30 eyes) participated in the study. Fd-OCT imaging using a commercially available device (Spectralis® HRA+OCT; Heidelberg Engineering Inc., Heidelberg, Germany) was performed at the same visit by one experienced examiner (D.C.) and by one inexperienced examiner (A.C.). Circular (3.4 millimeters in diameter) scans centered on the optic disc, in "high-speed" mode with the "automatic real time" mean module set at 16 frames, were used. After acquisition of the first circular B-scan, two additional peripapillary scans were obtained by each examiner, with and without the EBF function activated. Intraclass correlation coefficients (ICC) and repeatability coefficients (RC) were calculated.
Results: :
Mean (SD) global RNFL thickness was 104.3 (10.6) µm for the experienced examiner and 105.3 (9.7) µm for the inexperienced examiner (ICC = 0.93, RC = 7.6 µm). Interobserver analysis of peripapillary regions in separate revealed an ICC ≥0.90 for all but temporal region (ICC = 0.45, RC = 16.3 µm). Intraobserver analysis without the use of EBF function revealed an ICC <0.90 in two regions: superotemporal (ICC = 0.85, RC = 17.5 µm) and temporal (ICC = 0.64, RC = 13.3 µm). With the EBF function activated, the ICC increased to 0.97 (RC = 7.0 µm) in the superotemporal region and to 0.90 (RC = 7.0µm) in the temporal region, with an ICC ≥ 0.98 for the remaining regions and for the global RNFL thickness measurements.
Conclusions: :
The EBF function had no significant influence in the reproducibility of the global peripapillary RNFL thickness measurements in healthy subjects. However, the reproducibility of the RNFL thickness measurements in the superotemporal and temporal regions was greater with the EBF function activated.
Keywords: imaging/image analysis: clinical • optic disc • retina