Associations of Ganglion Cell-Inner Plexiform Layer and Optic Nerve Head Parameters with Visual Field Sensitivity in Advanced Glaucoma

Abstract

Purpose: To evaluate the associations of optical coherence tomography (OCT)-derived macular ganglion cell-inner plexiform layer thickness (mGCIPLT), circumpapillary retinal nerve fiber layer thickness (cpRNFLT), and optic nerve head (ONH) parameters with visual field (VF) sensitivity in advanced glaucoma. Methods: In this cross-sectional study, 102 eyes from 102 patients with advanced glaucoma (defined as a 24-2 VF mean deviation (MD) of ≤−12 dB) were included. mGCIPLT, cpRNFLT, and ONH parameters (including the rim area, average cup-to-disc [C:D] ratio, and vertical C:D ratio) were measured using Cirrus high-definition OCT, and 24-2 and 10-2 VF sensitivity tests were performed using standard automated perimetry. Pearson correlations and linear models were used to analyze relationships between OCT-derived parameters and VF parameters. Results: The mGCIPLT and rim area were significantly positively correlated with the 24-2 VF MD, 24-2 VF pattern standard deviation, 24-2 VF visual field index, and 10-2 VF MD, but cpRNFLT was not significantly correlated with VF parameters. In addition, the average and vertical C:D ratios were significantly negatively correlated with VF parameters. The mGCIPLT and rim area were significantly positively correlated with the 10-2 VF MD (r ranging between 0.542 and 0.621, p < 0.001), while the average and vertical C:D ratios were significantly negatively correlated with the 10-2 VF MD (r = −0.537, p < 0.001, and r = −0.428, p < 0.001, respectively). Each 1-µm change in the average mGCIPLT was associated with an approximately 0.368-dB change in the 24-2 VF MD and 0.677-dB change in the 10-2 VF MD (R² = 0.268, p < 0.001, and R² = 0.385, p < 0.001, respectively). The 10-2 VF MD showed a significantly stronger association with inferonasal mGCIPLT than did the 24-2 VF MD in advanced glaucoma (p = 0.007). Conclusions: mGCIPLT and ONH parameters were associated with the severity of VF damage and reflected functional damage better than cpRNFLT in advanced glaucoma. Our results suggested that structural measurements of mGCIPLT and ONH parameters and functional measurement of the 10-2 VF may be useful for monitoring progression in advanced glaucoma.