Glaucoma Diagnosis
Conditions
Brief summary
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
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.
Interventions
DIAGNOSTIC_TESTOptical Coherence Tomography
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.
DIAGNOSTIC_TESTVisual evoked potential
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.
Sponsors
Wills Eye
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 90 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Visual Evoked Potential (VEP) | 1 examination, one hour | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Retinal Nerve Fiber Layer Thickness | 1 examination, one hour | Optical coherence tomography (OCT) images provide measurement of the retinal nerve fiber layer thickness in microns. |
Countries
United States
Participant flow
Recruitment details
Glaucoma patients, suspects and healthy subjects were recruited between 2011 and 2012 in the Glaucoma Service at Wills Eye Hospital, Philadelphia, Pennsylvania, USA.
Participants by arm
| Arm | Count |
|---|---|
| Healthy Subjects 42 Healthy subjects with intraocular pressure less than 22 millimeters of mercury (mmHg), normal optic discs and retinal nerve fiber layer, normal optical coherence technology (RNFL thickness) and normal visual fields in both eyes for optical coherence tomography (OCT) and visual evoked potential testing (VEP).
Optical Coherence Tomography: 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.
Visual evoked potential: Visual evoked potential is a means of objectively testing visual field by viewing a computer monitor at 1 meter wit | 42 |
| Glaucoma Suspects 45 Glaucoma suspects with glaucomatous optic discs and/or thin retinal nerve fiber layer in at least one eye, normal optical coherence technology and normal visual field results will have optical coherence tomography and visual evoked potential.
Optical Coherence Tomography: 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.
Visual evoked potential: Visual evoked potential is a means of objectively testing visual field by viewing a computer monitor at 1 meter with a square black/white check | 45 |
| Glaucoma Patients 49 Glaucoma patients with repeatable abnormal visual fields, glaucomatous optic disc (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 will have optical coherence tomography and visual evoked potential.
Optical Coherence Tomography: 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.
Visual evoked potential: Visual evoked potential is a means of objectively testing visu | 49 |
| Total | 136 |
Baseline characteristics
| Characteristic | Total | Healthy Subjects | Glaucoma Suspects | Glaucoma Patients |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 41 Participants | 12 Participants | 13 Participants | 16 Participants |
| Age, Categorical Between 18 and 65 years | 95 Participants | 30 Participants | 32 Participants | 33 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 5 Participants | 1 Participants | 4 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 56 Participants | 11 Participants | 24 Participants | 21 Participants |
| Race (NIH/OMB) More than one race | 5 Participants | 0 Participants | 4 Participants | 1 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 70 Participants | 30 Participants | 13 Participants | 27 Participants |
| Region of Enrollment United States | 136 participants | 42 participants | 45 participants | 49 participants |
| Sex: Female, Male Female | 57 Participants | 12 Participants | 18 Participants | 27 Participants |
| Sex: Female, Male Male | 79 Participants | 30 Participants | 27 Participants | 22 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 42 | 0 / 45 | 0 / 49 |
| other Total, other adverse events | 0 / 42 | 0 / 45 | 0 / 49 |
| serious Total, serious adverse events | 0 / 42 | 0 / 45 | 0 / 49 |
Outcome results
Primary
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.
Time frame: 1 examination, one hour
Population: measurement is amplitude in microvolts (uV), the peak strength of the signal, when presented with low contrast stimuli
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Healthy Subjects | Visual Evoked Potential (VEP) | 6.7 microvolts (uV) (amplitude) | Standard Deviation 3.3 |
| Glaucoma Suspects | Visual Evoked Potential (VEP) | 7.1 microvolts (uV) (amplitude) | Standard Deviation 3.9 |
| Glaucoma Patients | Visual Evoked Potential (VEP) | 4.1 microvolts (uV) (amplitude) | Standard Deviation 2.7 |
Secondary
Retinal Nerve Fiber Layer Thickness
Optical coherence tomography (OCT) images provide measurement of the retinal nerve fiber layer thickness in microns.
Time frame: 1 examination, one hour
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Healthy Subjects | Retinal Nerve Fiber Layer Thickness | 95.1 microns (thickness) | Standard Deviation 8.7 |
| Glaucoma Suspects | Retinal Nerve Fiber Layer Thickness | 87.5 microns (thickness) | Standard Deviation 13.4 |
| Glaucoma Patients | Retinal Nerve Fiber Layer Thickness | 71.2 microns (thickness) | Standard Deviation 12.1 |