Clinical trial NCT02600403: Are There Changes in the Nerve Fiber Layer (NFL) After Lowering of Eye Pressure?
Official title: Reversible Structural and Functional Changes After Intraocular Pressure Reduction in Patients With Glaucoma
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Glaucoma
Keywords: Visual Evoked Potentials
Optical Coherence Tomography
Visual Fields
Lead sponsor: Wills Eye
Sponsor class: OTHER
First posted: 2015-11-09
Enrollment: 61
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
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).

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).

Detailed description: Glaucoma exhibits characteristic changes to the optic nerve in the back of the eye. The optic nerve is formed when fibers that overlay the retina come together. This layer is called the retinal nerve fiber layer (RNFL).

Optical Coherence Tomography (OCT) is a machine that scans eyes and has the capability of measuring thickness of various layers in the retina and RNFL. This provides important anatomical information.

VEP (visual evoked potential) is an imaging system that measures electrical signals from the eye to the brain by using electrodes placed on the forehead and back of head. This is similar in principal to an electrocardiogram of the heart.

Visual field testing is done to evaluate the extent of side vision loss caused by various diseases of the eye, including glaucoma. This testing is performed as you stare at a small light directly in front of your eye while lights flash one at a time in every direction on a screen surrounding the central light. You push a button each time you see a flash out of the corner of your eye.

Lowering intraocular pressure (IOP) in the eye has been shown to result in reversal of glaucoma changes of the optic nerve in some patients. It has also been suggested that improvement in function (visual field) has been associated with improved optic nerve appearance.

This study seeks to provide evidence for reversal of disc appearance and visual function following IOP lowering interventions.

Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Visual Field Mean Deviation
timeFrame: 12 months
measure: Retinal Nerve Fiber Layer (RNFL) Thickness Measurement
timeFrame: 12 months
measure: Average Cup to Disc Ratio
timeFrame: 12 months
measure: Visual Evoked Potential Amplitudes
timeFrame: 12 months
measure: Visual Evoked Potential Latency
timeFrame: 12 months
measure: Visual Field
timeFrame: 12 months
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: Wills Eye
name: George Spaeth, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.