[Variability of optical coherence tomography in assessment of optic disc and retinal nervous fibre layer].
OBJECTIVE
To study the short-term variability of retinal nerve fiber layer (RNFL) and optic disc measurements using Stratus OCT.


METHODS
Transversal comparative study with repeated measurements. For each eye, the Fast Optic Disc and Fast RNFL protocols were repeated twice in the same session. The resulted measurements were compared using correlation and variation coefficients.


RESULTS
62 eyes (34 patients) were included in the study. For every analyzed parameter there was a highly significant correlation between the first and the second measurement (p < 0.001). For the C/D ratio (vertical, horizontal and area) the correlation coefficients varied from 0.939 to 0.961 (coefficients of variation 6.43 to 8.75%). Concerning the RNFL parameters, the correlation coefficients took values between 0.818 (for the nasal quadrant) and 0.964 (for the Average Thickness). The variation coefficients were between 4.24 and 15.14%.


CONCLUSIONS
We have found an excellent reproducibility of C/D measurements (vertical, horizontal and area)--less studied in the OCT-related literature. From the RNFL parameters, the best reproducibility was found for the superior and inferior quadrant, and especially for the average thickness.
Danielescu
C
C
Clinica I Oftalmologie, Iaşi.
Chiseliţa
D
D
D003430:Cross-Sectional Studies; D006801:Humans; D009898:Optic Disk / Q000000981:diagnostic imaging / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011859:Radiography; D015203:Reproducibility of Results; D012160:Retina / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000473:pathology; D055351:Retinal Neurons / Q000473:pathology*; D041623:Tomography, Optical Coherence