Are There Changes in the Nerve Fiber Layer (NFL) After Lowering of Eye Pressure?

NCT02600403 | Completed Results

• 1 other identifier: 11-058
• Study Type: observational
• Target: 61
• Locations: 0 countries
• Sites: N/A

Brief Summary

The aim of this study was to evaluate structural and functional improvement after lowering intraocular pressure (IOP) in patients with glaucoma using Spectral Domain Optical Coherence Tomography (SD-OCT), Visual Field (VF) testing, and Visual Evoked Potential (VEP).

Conditions

Glaucoma

Keywords

Visual Evoked Potentials; Optical Coherence Tomography; Visual Fields

Outcome Measures

Primary Outcomes (6)

• Visual Field Mean Deviation

  Visual field mean deviation as measured in decibels (dB) is the amount of visual field loss compared to age matched controls (people with no eye diseases or visual field loss). Brightness of the flashes of light used to test peripheral vision during a visual field test is measured in decibels. Brighter light has lower number in decibels. The dimmer the light, the higher the number in decibels with a range of 0 to 40 dB.

  12 months

• Retinal Nerve Fiber Layer (RNFL) Thickness Measurement

  Retinal nerve fiber layer (RNFL) thickness in different quadrants of optic nerve and macula are measured pre and postoperatively to evaluate structural changes.

  12 months

• Average Cup to Disc Ratio

  Cup to disc ratio is used to evaluate structural changes comparing the size of the cup to the size of the disc during dilated ophthalmic examination. High eye pressure can cause the cup to enlarge, closer to the size of the disc. This measurement is used to follow progression in glaucoma. A normal range for cup to disc ratio would be 0.0 to 0.4. Advanced glaucoma would be 0.8 to 0.9 cup to disc ratio.

  12 months

• Visual Evoked Potential Amplitudes

  VEP amplitudes at high contrast as measured in microvolts (μV). Electroencephalogram (EEG) measures electrical activity in the brain. VEP measures electrical activity in areas of the brain responsible for vision by using EEG electrodes. The amplitude measurement is the peak of the energy generated (strongest strength of the signal) from the eye's response to the visual stimulus during the VEP.

  12 months

• Visual Evoked Potential Latency

  VEP latency at high contrast as measured in milliseconds (ms). Electroencephalogram (EEG) measures electrical activity in the brain. VEP measures electrical activity in areas of the brain responsible for vision by using EEG electrodes. VEP latencies measure the duration in time of the energy generated (duration of the signal) from the eye's response to a visual stimulus during the VEP.

  12 months

• Visual Field

  Visual field pattern standard deviation in decibels (dB). Visual field results compare visual field loss to age matched controls (people with no eye diseases or visual field loss). Brightness of the flashes of light used to test peripheral vision during a visual field test is measured in decibels. With a localized defect in the visual field, pattern standard deviation (PSD) quantifies amount of loss and progression of glaucoma when in the beginning stages of the disease.

  12 months

Study Arms (3)

IOP between 22-32 mmHg

Forty four (44) patients with intraocular pressure between 22 and 32 millimeters (mmHg) of mercury will undergo Optical Coherence Tomography (OCT); Visual Evoked Potential (VEP); and Humphrey Visual Field (HVF).

Diagnostic Test: Optical Coherence Tomography (OCT); Diagnostic Test: Visual evoked potential (VEP); Diagnostic Test: Humphrey Visual Field (HVF)

IOP greater than 32 mmHg

Six (6) patients with intraocular pressure greater than 32 millimeters of mercury (mmHg) will undergo Optical Coherence Tomography (OCT); Visual Evoked Potential (VEP); and Humphrey Visual Field (HVF).

Diagnostic Test: Optical Coherence Tomography (OCT); Diagnostic Test: Visual evoked potential (VEP); Diagnostic Test: Humphrey Visual Field (HVF)

IOP less than 22 mmHg

Eleven (11) patients with stable intraocular pressure (less than 22 millimeters of mercury (mmHg)) on ophthalmic solutions (eye drops) will undergo Optical Coherence Tomography (OCT); Visual Evoked Potential (VEP); and Humphrey Visual Field (HVF).

Diagnostic Test: Optical Coherence Tomography (OCT); Diagnostic Test: Visual evoked potential (VEP); Diagnostic Test: Humphrey Visual Field (HVF)

Interventions

Optical Coherence Tomography (OCT) DIAGNOSTIC_TEST

Optical Coherence Tomography (OCT) is a machine that scans eyes and has the capability of measuring thickness of various layers of the retina and nerve fiber layer (NFL).

Also known as: OCT

IOP between 22-32 mmHg; IOP greater than 32 mmHg; IOP less than 22 mmHg

Visual evoked potential (VEP) DIAGNOSTIC_TEST

Visual Evoked Potential (VEP) is an imaging system that measures electrical activity from the eye to the brain by using electrodes placed on forehead and back of the head similar to electroencephalogram (EEG).

Also known as: VEP

IOP between 22-32 mmHg; IOP greater than 32 mmHg; IOP less than 22 mmHg

Humphrey Visual Field (HVF) DIAGNOSTIC_TEST

Humphrey Visual Field (HVF) is a test done to evaluate how much peripheral (side) vision has been lost due to glaucoma.

Also known as: VF

IOP between 22-32 mmHg; IOP greater than 32 mmHg; IOP less than 22 mmHg

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Glaucoma patients with intraocular pressure (IOP) between 22 and 32 millimeters of mercury (mm HG); greater than 32 mm HG; and with stable IOPs (control group).

You may qualify if:

• All patients with glaucoma (primary open-angle glaucoma, angle recession glaucoma, exfoliation syndrome glaucoma, pigmentary glaucoma and chronic angle closure glaucoma) in whom a pressure-lowering intervention was conducted

You may not qualify if:

• Inability to obtain reliable field or optical coherence tomography pre-intervention
• Visual acuity less than 20/40,
• Age \<18 or \>90 years,
• Other cause for visual field loss not glaucoma, that is, visual field loss due to cataract optic neuropathies, retinal disease
• Spherical equivalent refractive error \> +5.00 Diopters and \> 3.00 Diopters cylinder
• Concomitant cataract and glaucoma surgery

Sponsors & Collaborators

• Wills Eye: lead

Related Publications (2)

• Jindal AP, Fleischman D, Leiby B, Spaeth GL, Myers JS, Katz LJ. Effects of acutely lowering intraocular pressure on the results of multifocal visual evoked potential testing. Acta Ophthalmol. 2011 Nov;89(7):e550-4. doi: 10.1111/j.1755-3768.2011.02177.x. Epub 2011 May 23.

  PMID: 21599873 BACKGROUND

• Waisbourd M, Ahmed OM, Molineaux J, Gonzalez A, Spaeth GL, Katz LJ. Reversible structural and functional changes after intraocular pressure reduction in patients with glaucoma. Graefes Arch Clin Exp Ophthalmol. 2016 Jun;254(6):1159-66. doi: 10.1007/s00417-016-3321-2. Epub 2016 Mar 19.

  PMID: 26995555 BACKGROUND

MeSH Terms

Conditions

Glaucoma

Interventions

Tomography, Optical Coherence; Evoked Potentials, Visual

Condition Hierarchy (Ancestors)

Ocular Hypertension; Eye Diseases

Intervention Hierarchy (Ancestors)

Tomography, Optical; Optical Imaging; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Tomography; Investigative Techniques; Evoked Potentials; Cortical Excitability; Electrophysiological Phenomena; Physiological Phenomena; Nervous System Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Ocular Physiological Phenomena

Limitations and Caveats

Small sample size. Patients grouped by baseline intraocular pressure not by intervention. Inconsistent follow-up times. Subset of moderate to advanced glaucoma precluding possibility of reversible VEP changes in earlier stages of glaucoma.

Results Point of Contact

• Title: Michael Waisbourd
• Organization: Wills Eye Hospital

MWaisbourd@willseye.org

2159283000

Study Officials

• George Spaeth, MD

  Wills Eye

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Study Record Dates

• First Submitted: August 10, 2015
• First Posted: November 9, 2015
• Study Start: October 1, 2011
• Primary Completion: January 1, 2013
• Study Completion: January 1, 2013
• Last Updated: March 19, 2018
• Results First Posted: March 19, 2018

Record last verified: 2018-03

Data Sharing

• IPD Sharing: Will not share