Abstract
Purpose: :
To determine the reproducibility of Spectralis optical coherence tomography (OCT) peripapillary retinal nerve fiber layer (RNFL) measurements in eyes with the spectrum of glaucomatous visual field loss.
Methods: :
One eye from 63 stable glaucoma patients with a range of severity was imaged with spectral domain OCT (Spectralis; Heidelberg Engineering, Heidelberg, Germany) 6 times on 2 separate visits within 1 week (3 times on each visit) to determine intravisit and intervisit variability. Patients were divided into 3 groups according to the visual field mean deviation (MD) value; early (MD >-6, n=25), moderate (-12<MD≤-6, n=19) and advanced (MD≤-12, n=19) glaucoma groups. Intraclass correlation coefficient (ICC), coefficient of variation (CV) and test-retest variability was determined and compared between the groups.
Results: :
The ICC for average RNFL measurement were 0.99, 0.97 and 0.99 in early, moderate and advanced glaucoma groups and the CV ranged from 1.4 to 4.0 %. For average RNFL thickness, the intravisit test-retest variabilities were 2.51 [confidence interval (CI), 1.96-3.49], 3.43 (CI, 2.59-5.07) and 4.04 (CI, 3.05-5.97) µm and the intervisit variabilities were 2.63 (CI, 2.05-3.66), 4.87 (CI, 3.68-7.20) and 4.16 (CI, 3.14-6.15) µm in early, moderate and advanced glaucoma groups, respectively.
Conclusions: :
The reproducibility of spectralis OCT for RNFL thickness is excellent in all glaucomatous eyes with different severity of visual field loss.
Keywords: imaging/image analysis: clinical • optic disc • nerve fiber layer