Short-duration transient visual evoked potentials and color reflectivity discretization analysis in glaucoma patients and suspects

Abstract

Aim: To evaluate the use of short-duration transient visual evoked potentials (VEP) and color reflectivity discretization analysis (CORDA) in glaucomatous eyes, eyes suspected of having glaucoma, and healthy eyes.

Methods: The study included 136 eyes from 136 subjects: 49 eyes with glaucoma, 45 glaucoma suspect eyes, and 42 healthy eyes. Subjects underwent Humphrey visual field (VF) testing, VEP testing, as well as peripapillary retinal nerve fiber layer optical coherence tomography imaging studies with post-acquisition CORDA applied. Statistical analysis was performed using means and ranges, ANOVA, post-hoc comparisons using Turkey's adjustment, Fisher's Exact test, area under the curve, and Spearman correlation coefficients.

Results: Parameters from VEP and CORDA correlated significantly with VF mean deviation (MD) (P<0.05). In distinguishing glaucomatous eyes from controls, VEP demonstrated area under the curve (AUC) values of 0.64-0.75 for amplitude and 0.67-0.81 for latency. The CORDA HR1 parameter was highly discriminative for glaucomatous eyes vs controls (AUC=0.94).

Conclusion: Significant correlations are found between MD and parameters of short-duration transient VEP and CORDA, diagnostic modalities which warrant further consideration in identifying glaucoma characteristics.

Keywords: color reflectivity discretization analysis; glaucoma; optical coherence tomography; short-duration transient visual evoked potentials.

Figures

Figure 1. Examples of reports from SD-tVEP (left panel) and the CORDA (right panel) protocol in a normal control

A: The output from the SD-tVEP protocol. This includes waveforms indicating the change in amplitude over time for each eye with respect to low contrast (gray) and high contrast (black) stimuli (top two graphs); B: The output from the CORDA protocol. This includes the traditional B-scan images for each eye (top two images) as well as sectorial discretization images (bottom two images) for each eye (left and right images). The CORDA parameters for high reflectivity (HR1 and HR2) and low reflectivity (LR1 and LR2) are presented for each eye.

Figure 2. Correlation of MD and CORDA high reflectivity parameters (HR1 and HR2).

Figure 3. Age against CORDA high reflectivity parameters (HR1 and HR2).