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

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.

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
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