NCT02604953

Comparing SD-tVEP and PERG Tests Between Patients With Glaucoma, Patients With High Eye Pressure and "Normal" Patients

1-Year Prospective Study: SD-tVEP and PERG for Early Detection of Retinal Ganglion Cell Dysfunction in Ocular Hypertension Patients

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 90 (actual)
• Sponsor: Wills Eye · Academic / Other
• Sex: All
• Age: 21 Years – 80 Years
• Healthy volunteers: Accepted

Summary

Wills Eye Hospital Glaucoma Research Center will conduct a 1-year prospective study to assess the ability of a Short Duration Transient Visual Evoked Potential (SD- tVEP) and a Steady-State Pattern electro-retinogram (PERG) vision testing system to detect visual dysfunction in patients with ocular hypertension. The study aims to assess the reversibility of retinal ganglion cell (RGC) dysfunction after administering intraocular pressure (IOP) lowering treatment. The investigators hypothesize that SD-tVEP and PERG testing will help develop better treatment for glaucoma patients by increasing understanding of the physiological relationship of IOP and RGC in glaucomatous injury.

Detailed description

Glaucoma is the most common cause of irreversible blindness worldwide. It is characterized by the progressive loss of retinal ganglion cells (RGCs) and a corresponding loss of vision. Elevated intraocular pressure (IOP) is an important risk factor for glaucoma, but its role in the diagnosis of glaucoma is unclear. Although IOP-lowering therapy delays the onset of glaucoma in some patients with ocular hypertension, even without therapy, 90% of patients will not develop glaucoma over a 5-year period. Visual evoked potentials (VEPs) are able to detect the disruption of electrical signals at any point along the visual pathway, from the RGCs to the primary visual cortex. As an objective measure of visual function, the VEP may have an advantage over traditional visual field tests, by reducing confounded factors such as age, fatigue, and mental status. There is a growing body of evidence that SD-tVEP can objectively identify early visual dysfunction due to glaucoma. Aim 1: Compare the results of the baseline SD-tVEP and PERG vision testing in patients with ocular hypertension to a cohort of 30 healthy subjects and a cohort of 30 patients with glaucoma (of varying severity) to determine its ability to detect visual dysfunction in ocular hypertensive subjects. Aim 2: Conduct SD-tVEP and PERG testing system in 30 patients with ocular hypertension before and after IOP reduction with topical medication and compare the results of the SD-tVEP and PERG before and after treatment in each patient, to determine its ability to detect reversible RGC dysfunction.

Conditions

• Glaucoma

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Short Duration Transient Visual Evoked Potential (SDtVEP)	Short duration transient visual evoked potentials (VEPs) detect disruption of electrical signals at any point along the visual pathway, from the retinal ganglion cells (RGCs) to the primary visual cortex. As an objective measure of visual function, VEP may have advantage over traditional visual field tests, by reducing confounded factors such as age, fatigue, and mental status.
DIAGNOSTIC_TEST	Pattern electroretinogram (PERG)	Pattern electroretinogram (PERG), an objective test, is used for evaluating early damage to retinal ganglion cells (RGC). In PERG, retinal response is recorded while patterns are viewed in the visual field on a computer monitor.

Timeline

• Start date: 2014-07-01
• Primary completion: 2015-06-01
• Completion: 2015-07-01
• First posted: 2015-11-16
• Last updated: 2017-12-02