Figure 1.
Macular area centered on the fovea (6×6 mm) and mRNFL and GCIPL grids, and the RNFL thickness along a 3.4-mm diameter circle centered on the disc barycenter.
a: Macular area centered on the fovea (6×6 mm) and mRNFL and GCIPL grids. The mRNFL and GCIPL grids at the most outer circumference (sectors 1–10, 11, 20, 21, 30, 31, 40, 41, 50, 51, 60, 61, 70, 71, 80, 81, 90–100: colored in grey) were excluded from analysis. If a subject’s left eye was measured, recorded data were mirror-imaged to reflect those in the right eye. b: RNFL thickness along a 3.4-mm diameter circle centered on the disc barycenter. T: temporal, TS: temporal-superior, ST: superior-temporal, S: superior, SN: superior-nasal, NS: nasal-superior, N: nasal, NI: nasal-inferior, IN: inferior-nasal, I: inferior, IT: inferior-temporal, TI: temporal-inferior.
Table 1.
SD-OCT parameters used in the Random Forests method.
Table 2.
Characteristics of the study participants.
Figure 2.
The mRNFL and GCIPL grid giving the largest AROC.
a: Largest AROC (94.3 [CI: 91.1–97.6] %) was obtained using the mRNFL grid with reference 82 (highlighted red). b: Largest AROC (91.2 [CI: 87.3–95.1] %) was obtained using the GCIPL grid with reference 62 (highlighted red). OCT: optical coherent tomography, AROC: area under the receiver operating characteristic curve, mRNFL: macular retinal nerve fiber layer, GCIPL: ganglion cell layer -inner plexiform layer combined. CI: 95% confidence interval.
Figure 3.
Receiver operating characteristic (ROC) curves obtained with the Random Forests method and the best performing cpRNFL-, mRNFL- or GCIPL-related parameters.
The area under the ROC (AROC) with the Random Forests method was significantly larger than those with the individual cpRNFL-, mRNFL- or GCIPL-related parameters (P<0.001, DeLong’s method. All P values were significant after correction for multiple testing using Holm’s method [43], [44]). The orange dot on the ROC of the Random Forests method represents the optimal threshold; the voting rate at this point was 55.3%, giving a sensitivity of 92.9% with specificity equal to 96.0%. [47] cpRNFL: circumpapillary retinal nerve fiber layer (RNFL), mRNFL: macular RNFL, GCIPL: ganglion cell layer- inner plexiform layer combined.
Table 3.
AROCs with summary SD-OCT measures.
Figure 4.
mRNFL (Figure 4a) and GCIPL grids (Figure 4b) that significantly contributed to the discrimination of glaucoma eyes from normal eyes (highlighted in red).
mRNFL: macular retinal nerve fiber layer (RNFL), GCIPL: ganglion cell layer and inner plexiform layer combined.