Usefulness of Macular Thickness Derived from Spectral-domain Optical Coherence Tomography in the Detection of Glaucoma Progression

Purpose: To assess the reproducibility of circumpapillary retinal nerve fiber layer thickness (cRNFLT) and total macular thickness (TMT) parameters using Cirrus spectral domain optical coherence tomography (SD-OCT) and to apply this information to investigate its ability to detect cases where visual field (VF) progression was noted on event-based analysis in the eyes with early glaucomatous VF loss.

Methods: Intraclass correlation coefficient (ICC), coefficient of variation (COV), and intersession test-retest variability were calculated from the control group. The sensitivity and specificity of SD-OCT for the identification of progressive VF defects were tested on progressive and stable patients.

Results: All ICCs from cRNFLT and TMT measurements ranged from 94.8% to 99.0%. While average cRNFLT showed the lowest intersession COV (2.57%), the nasal-outer and superior-inner TMT sectors showed the lowest COV (0.96%). The sensitivities of Cirrus SD-OCT cRNFLT measurements ranged from 37.8% to 48.9%, while that of TMT measurement was 73.3% when tested at the 95% confidence interval (CI). The sensitivity for detecting progressive VF changes in the central 10° area improved to 84.8% with TMT measurement, while it remained unchanged with cRNFLT measurements. The agreement on progression detection between cRNFLT and TMT sector measurements was poor (κ = 0.072 for overall, and 0.102 for the central 10° area at 95% CI, respectively).

Conclusions: Intersession measurements of both cRNFLT and TMT parameters with Cirrus SD-OCT showed excellent reproducibility. TMT parameters using Cirrus SD-OCT may be better than cRNFLT measurements in terms of detecting progressive VF loss. This sensitivity derived from TMT measurements increased when progressive VF loss occurred in the central 10° area.