How Accurately Does the Diopsys Visual Evoked Potential (VEP) Vision Testing System Detect Glaucoma?

Study Overview
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Brief Summary
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Evaluate sensitivity and specificity of NOVA-DN visually evoked potentials (VEP) protocol and new software method (Corda) for glaucoma detection using optical coherence tomography (OCT) images to differentiate between normal subjects and glaucoma suspects.

Detailed Description
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The aim of this study was to evaluate the ability of NOVA-DN VEP protocol and Corda parameters to discriminate between healthy eyes and eyes with early to moderate glaucomatous visual field loss. We will evaluate measurements of the NOVA-DN VEP protocol, Corda software and Cirrus spectral domain (SD) OCT software in order to compare and correlate. Hypotheses is that NOVA-DN VEP protocol and Corda analysis results in a high sensitivity, specificity and area under the Receiver Operating Characteristic (ROC) curves (ROC area) for glaucoma detection. Second hypothesis is NOVA-DN VEP protocol and Corda parameters can differentiate between normal and glaucoma suspects.

Official Title
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Sensitivity and Specificity of the NOVA-DN VEP Protocol and a Novel Analysis of Optical Coherence Tomography Images for Glaucoma Diagnosis

Conditions
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Glaucoma Diagnosis

Intervention / Treatment
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* Diagnostic Test: Optical Coherence Tomography
* Diagnostic Test: Visual evoked potential


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Group 1: Healthy Subjects intraocular pressure less than 22 millimeters of mercury (mmHg) normal appearing optic discs and retinal nerve fiber layer (RNFL) normal optical coherence tomography (OCT) RNFL thickness normal visual field (VF) results in both eyes. Group 2: Glaucoma Suspects glaucomatous appearance of optic discs and/or RNFL in at least one eye normal OCT normal VF results in both eyes. Group3: Glaucoma Patients Glaucomatous optic disc appearance (cup to disc ratio, rim thinning or RNFL defects) Repeatable intraocular pressure (IOP) of 23 mmHg or more, in at least one eye Repeatable abnormal VF tests Exclusion Criteria: inability to perform reliable VF or OCT visual acuity worse than 20/40 refractive error greater than +/-5.00 diopters sphere, greater than +/- 3.00 diopers cylinder

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Healthy Subjects<br>42 Healthy subjects with intraocular pressure less than 22 millimeters of mercury (mmHg), normal appearing optic discs and retinal nerve fiber layer, normal optical coherence technology (RNFL thickness) and normal visual field results in both eyes. Participants will have optical coherence tomography (OCT) and Diopsys visual evoked potential testing (VEP). | Diagnostic Test: Optical Coherence Tomography<br>* Optical coherence tomography (OCT) is a noninvasive imaging modality that provides micrometer-scale resolution.It has been revolutionized in recent years by exploitation of Fourier domain (FD) techniques, which have a significant sensitivity advantage over traditional time domain (TD) OCT. In spectral-domain (SD-OCT) the reference mirror is stationary, and OCT signal is acquired using a spectrometer as detector or by varying the wavelength of the light source.<br>* Other names: OCT;Diagnostic Test: Visual evoked potential<br>* Visual evoked potential is a means of objectively testing visual field by viewing a computer monitor at 1 meter with a square black/white checkerboard pattern reversal stimulus. Electrodes are placed on the head and face to monitor Electroencephalogram (EEG) activity during testing. Output parameters from VEP system include amplitude and latency measures for each stimuli.<br>* Other names: VEP;|
| Experimental: Glaucoma Suspects<br>45 Glaucoma suspects with glaucomatous appearance optic discs and/or thin retinal nerve fiber layer in at least one eye, normal optical coherence technology (RNFL thickness) and normal visual field results in both eyes. Participants will have optical coherence tomography (OCT) and Diopsys visual evoked potential testing (VEP). | Diagnostic Test: Optical Coherence Tomography<br>* Optical coherence tomography (OCT) is a noninvasive imaging modality that provides micrometer-scale resolution.It has been revolutionized in recent years by exploitation of Fourier domain (FD) techniques, which have a significant sensitivity advantage over traditional time domain (TD) OCT. In spectral-domain (SD-OCT) the reference mirror is stationary, and OCT signal is acquired using a spectrometer as detector or by varying the wavelength of the light source.<br>* Other names: OCT;Diagnostic Test: Visual evoked potential<br>* Visual evoked potential is a means of objectively testing visual field by viewing a computer monitor at 1 meter with a square black/white checkerboard pattern reversal stimulus. Electrodes are placed on the head and face to monitor Electroencephalogram (EEG) activity during testing. Output parameters from VEP system include amplitude and latency measures for each stimuli.<br>* Other names: VEP;|
| Experimental: Glaucoma Patients<br>49 Glaucoma patients with repeatable abnormal visual fields, glaucomatous optic disc appearance (those with cup to disc ratio greater than 0.7, rim thinning or Retinal Nerve Fiber Layer defects indicative of glaucoma) and/or repeatable intra-ocular pressure of 23 mmHg or higher, in at least one eye. Participants will have optical coherence tomography (OCT) and Diopsys visual evoked potential testing (VEP). | Diagnostic Test: Optical Coherence Tomography<br>* Optical coherence tomography (OCT) is a noninvasive imaging modality that provides micrometer-scale resolution.It has been revolutionized in recent years by exploitation of Fourier domain (FD) techniques, which have a significant sensitivity advantage over traditional time domain (TD) OCT. In spectral-domain (SD-OCT) the reference mirror is stationary, and OCT signal is acquired using a spectrometer as detector or by varying the wavelength of the light source.<br>* Other names: OCT;Diagnostic Test: Visual evoked potential<br>* Visual evoked potential is a means of objectively testing visual field by viewing a computer monitor at 1 meter with a square black/white checkerboard pattern reversal stimulus. Electrodes are placed on the head and face to monitor Electroencephalogram (EEG) activity during testing. Output parameters from VEP system include amplitude and latency measures for each stimuli.<br>* Other names: VEP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual Evoked Potential (VEP) | Diopsys Visual evoked potential (VEP) (Diopsys, Inc. Pine Brook, NJ) is used to objectively measure the functional responses of the entire visual pathway from the anterior segment of the eye to the visual cortex. This is the strength of the signal recorded from the back of the head near where vision is processed in the brain while a visual stimulus is presented to patient. | 1 examination, one hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Retinal Nerve Fiber Layer Thickness | Optical coherence tomography (OCT) images provide measurement of the retinal nerve fiber layer thickness in microns. | 1 examination, one hour |