Purpose
To investigate the agreement between the retinal nerve fiber layer (RNFL) thickness measured by spectral domain (Spectralis) and swept source (DRI) optical coherence tomography (OCT), and to compare their glaucoma-discriminating capability.
Methods
This study included 55 healthy, 41 glaucoma suspects, and 87 glaucomatous eyes. RNFL thicknesses were measured with the scan circle centered on the optic nerve head. The RNFL thickness measured by the Spectralis (sdRNFL thickness) and DRI OCT (ssRNFL thickness) was compared using t-test. Bland-Altman analysis was performed to examine their agreement. Areas under the receiver operating characteristic curve (AROCs) of sdRNFL and ssRNFL thickness for discriminating glaucomatous eyes from healthy eyes, and glaucoma suspect eyes were compared.
Results
The average ssRNFL thickness was significantly greater than sdRNFL thickness in healthy (110.0±7.9 vs. 100±6.8 μm, P<0.001), glaucoma suspects (96.8±9.2 vs. 89.6±7.9 μm, P <0.001), and glaucomatous eyes (74.3±14.1 vs. 69.1±12.4 μm, P=0.011). Bland-Altman analysis showed a tendency that the difference between ssRNFL and sdRNFL became greater in eyes with thicker RNFL. The AROC of the average sdRNFL and ssRNFL thickness for discriminating glaucomatous eyes from healthy eyes (0.984 vs 0.986, P=0.492) and glaucoma suspect eyes (0.898 vs 0.888, P=0.463) was comparable.
Conclusions
The ssRNFL thickness was significantly different from sdRNFL.thickness. There was a tendency for ssRNFL thickness to be increasingly greater than sdRNFL thickness in eyes with thicker RNFL. The ssRNFL thickness had comparable diagnostic capability compared with sdRNFL thickness in discriminating glaucomatous eyes from healthy eyes and glaucoma suspect eyes.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
610 nerve fiber layer