Repeatability of Perimacular Ganglion Cell Complex Analysis with Spectral-Domain Optical Coherence Tomography

Abstract

Purpose. To assess the repeatability of spectral-domain optical coherence tomography to measure macular and perimacular ganglion cell complex thicknesses and compare retinal ganglion cell parameters between algorithms. Methods. Ninety-two nonglaucomatous eyes from 92 participants underwent macular and perimacular ganglion cell complex thickness measurement using OCT-HS100 Glaucoma 3D algorithm and these measurements were repeated for 34 subjects. All subjects also had macular ganglion cell-inner plexiform layer thickness measured by Cirrus HD-OCT Ganglion Cell Analysis algorithm. Intraclass correlation coefficient and Pearson's correlation analyses were performed. Results. Subfields of both macular and perimacular ganglion cell complex thicknesses had high intraclass correlation coefficient values between 0.979 (95% confidence interval [CI]: 0.958-0.989) and 0.981 (95% CI: 0.963, 0.991) and between 0.70 (95% CI: 0.481-0.838) and 0.987 (95% CI: 0.956-0.989), respectively. The overall average ganglion cell complex and macular average ganglion cell-inner plexiform layer thicknesses were strongly correlated (r = 0.83, P < 0.001). Conclusions. The assessment of macular and perimacular retinal ganglion cell parameters by OCT-HS100 Glaucoma 3D algorithm is highly repeatable, and strongly correlates to retinal ganglion cell parameters assessed by Ganglion Cell Analysis algorithm. A comprehensive evaluation of retinal ganglion cells may be possible with OCT-HS100.

Figure 1

Measurement grids of OCT-HS100 Glaucoma 3D algorithm. The grids are centered on the fovea and rotated in alignment with the centre of the optic disc. Both foveal centre and optic disc centre are aligned on the same axis to account for the influence of anatomic variation in the nerve fiber layer bundles.

Figure 2

Ganglion cell complex (GCC) thickness map of the right eye in OCT-HS100 Glaucoma 3D algorithm. The area bounded by the inner (1.5 mm) and middle (5 mm) circles forms the inner ring, while the area bounded by the middle (5 mm) and outer (10 mm) circles forms the outer ring. Thicknesses are averaged for the overall measurement, superior and inferior hemifields over the 10 mm diameter circle, and inner (macular GCC) and outer (perimacular GCC) subfields. The section of the nasal outer ring that encroached onto the optic disc and the central 1.5 mm in diameter area are excluded.