Structure–function relationship and diagnostic value of macular ganglion cell complex measurement using Fourier-domain OCT in glaucoma

Abstract

Purpose: To evaluate the relationship between visual function and macular ganglion cell complex (GCC) thickness measured by Fourier–domain optical coherence tomography (OCT) and evaluate the diagnostic value of GCC measurement compared to retinal nerve fiber layer (RNFL) thickness and macular thickness in detecting early, moderate, and severe glaucomas. Methods: Subjects underwent standard automated perimetry (SAP), OCT imaging with optic nerve head mode and GCC mode. The relationship between OCT parameters (mean GCC thickness, mean RNFL thickness, and macular thickness) and perimetry global indices (mean deviation [MD] and pattern standard deviation [PSD]) was evaluated by regression analysis. Diagnostic values of mean RNFL thickness, GCC parameters, and macular thickness were compared with the area under the receiver operating characteristic curves (AUC). Results: A total of 84 eyes, 42 of each normal and primary open-angle glaucoma patients were included in the study. Compared with linear models, second-order polynomial models better described relationships between GCC thickness and MD (P < 0.001), and between GCC thickness and PSD (P = 0.00). RNFL parameter, inferior RNFL thickness had the highest AUC for detecting early glaucoma. The AUC of mean GCC thickness for early glaucoma was higher than that of mean RNFL; however, the difference was not significant (P = 0.09), which was higher than that of macular thickness. Conclusion: The relationship between visual field (VF) sensitivity and GCC thickness is best expressed by the curvilinear function. Macular GCC thickness and RNFL thickness showed similar diagnostic values but were better than macular thickness for detecting early glaucoma but inferior to macular thickness and RNFL thickness for detecting moderate glaucoma.

Keywords

• gcc thickness
• macular thickness
• rnfl thickness