Utility of the Modified Isolated-check Visual Evoked Potential Technique in Functional Glaucoma Assessment

Abstract

Précis: Cortical response to low-contrast stimuli, as measured by isolated-check visual evoked potential (icVEP) technology, has the potential to provide functional assessment that may complement standard achromatic perimetry in assessing glaucomatous change. Purpose: To evaluate the utility of modified icVEP testing in detecting functional glaucomatous damage. Materials and Methods: Subjects who met predetermined criteria of controls, glaucoma suspects, preperimetric glaucoma, or glaucoma were enrolled in this prospective cross-sectional study from a single tertiary care center. Glaucoma patients were further categorized as early, moderate, advanced, or severe on the basis of Hodapp-Anderson-Parrish criteria. icVEP testing was performed with ten 2-second runs per qualified eye using the EvokeDx testing software. Multivariate statistics were used to calculate signal-to-noise ratios (SNR) and perform outlier analysis. Results: In total, 140 eyes met criteria (mean±SD; age of 63±14 y; 49% male; logMAR visual acuity, 0.11±0.089). There was no significant difference in age, sex, or logMAR visual acuity among the groups. Controls had a significantly higher SNR than all other groups (P<0.003), including patients with preperimetric glaucoma. Among those with glaucoma, the early glaucoma patients had significantly higher SNR than the moderate, advanced, or severe glaucoma cohorts (P<0.04). The optimal SNR cutoff for differentiating between glaucomatous and nonglaucomatous eyes was 0.95, both with (sensitivity 82%, specificity 76%) and without (sensitivity 82%, specificity 100%) glaucoma suspects included in analysis. Conclusions: icVEP technology has the potential to complement standard achromatic perimetry in functional assessment of glaucomatous defects.

Early impairment of magnocellular visual pathways mediated by isolated-check visual evoked potentials in primary open-angle glaucoma: a cross-sectional study

“…And the AUC of 16% DOM was 0.780. The accuracies of ic-VEP to differentiate patients with glaucoma from normal people differ according to the previous studies 14–16. The sensitivities differ by 70% from 82% and the specificities are between 75% and 99%.…”

“…Previous studies used the settled parameters of the machine as a tool for early POAG detection but did not modulate M-biased or P-biased stimulation. [14][15][16] At present, early glaucomatous visual impairment is still controversial, [17][18][19][20][21][22][23] and further clinical trials about objective evidence of early dysfunction in glaucoma are needed.…”

“…It is flexible to adjust the parameters of the spatial frequency, temporal frequency and contrast, which tend to modulate M-biased or P-biased stimulation. Previous studies used the settled parameters of the machine as a tool for early POAG detection but did not modulate M-biased or P-biased stimulation 14–16. At present, early glaucomatous visual impairment is still controversial,17–23 and further clinical trials about objective evidence of early dysfunction in glaucoma are needed.…”

Non-invasive electrophysiology in glaucoma, structure and function—a review

“… “ic-VEPs” (isolated-check VEPs, [ 49 ]) sweep contrast (or at least use 10% and 80%) and use the signal-to-noise ratio as a marker. With a commercial version (using an OLED monitor, so laudably without luminance artifacts), in a 140-eyes cross-sectional study, Kolomeyer et al [ 50 ] reported AUCs of up to 0.79, depending on whether favoring sensitivity or specificity. They also found progressive VEP affection from pre-perimetric over early and moderate to severe glaucoma.…”

Diagnostic Capability of Isolated-Check Visual Evoked Potential for Early to Moderate Primary Open-Angle Glaucoma

“…Recently, isolated-check VEPs (icVEPs), a new visual electrophysiology technology, have been reported to be able to detect glaucomatous visual damage early and quickly [ 7 ]. In recent years, this technique has been applied to detect optic nerve damage of glaucoma [ 8 , 9 , 10 , 11 , 12 , 13 ] and other diseases such as traumatic optic neuropathy [ 14 ] and dysthyroid optic neuropathy [ 15 , 16 ]. The specificity and sensitivity values in detecting glaucomatous optic nerve defects are 84.6–100% and 53.1–83%, respectively [ 7 , 8 , 9 , 10 , 11 ].…”