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Eye Pressure Lowering Surgery (IOP)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified April 2015 by Oregon Health and Science University.
Recruitment status was:  Recruiting
Information provided by (Responsible Party):
David Huang, Oregon Health and Science University Identifier:
First received: August 27, 2013
Last updated: April 21, 2015
Last verified: April 2015
The purpose of this study is to determine if lowering the pressure inside the eye improves blood flow to the eye.


Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective

Resource links provided by NLM:

Further study details as provided by Oregon Health and Science University:

Primary Outcome Measures:
  • Effects of Intraocular Pressure (IOP) Reduction on Ocular Perfusion [ Time Frame: 6 months ]
    To determine if IOP reduction improves ocular perfusion.

Estimated Enrollment: 40
Study Start Date: February 2014
Estimated Study Completion Date: June 2016
Estimated Primary Completion Date: June 2016 (Final data collection date for primary outcome measure)
Trabeculectomy Patients
20 glaucoma patients undergoing trabeculectomy surgery to lower IOP
Control Group
20 patients undergoing cataract surgery will be selected as a control group

Detailed Description:

Using high-speed ocular coherence tomography (OCT) systems, we have developed new methods to image and measure optic nerve head (ONH) and retinal blood flow. Preliminary results have shown that visual field (VF) loss is more highly correlated with retinal blood flow as measured by OCT than any neural structure measured by OCT or other imaging modality. Accordingly, the goal of the proposed project is to improve the diagnostic and prognostic evaluation of glaucoma by further developing novel functional OCT measurements using ultrahigh-speed (70-100 kHz) OCT technology.

Retinal blood flow, ONH circulation, optic disc rim volume, peripapillary nerve fiber layer volume, and macular ganglion cell complex volume are all pieces of the same glaucoma puzzle. This project will develop novel imaging methods that allow us to look at the whole picture using one tool - ultrahigh-speed OCT.


Ages Eligible for Study:   40 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
This study will measure blood flow changes in 20 glaucoma patients undergoing trabeculectomy surgery to lower IOP. Another 20 patients undergoing cataract surgery will be selected as a control group.

Inclusion Criteria:

  • Subjects diagnosed with perimetric open angle glaucoma or chronic angle closure glaucoma.
  • Subjects scheduled to undergo trabeculectomy surgery

Exclusion Criteria:

  • Best-corrected visual acuity less than 20/40
  • Age < 40 or >80 years
  • Refractive error of > +3.00 D or < -7.00 D
  • Previous vision correction surgery such as Laser-Assisted in situ Keratomileusis (LASIK) or Photorefractive Keratectomy (PRK)
  • Previous intraocular surgery except for uncomplicated cataract extraction with posterior chamber intraocular lens implantation
  • Diabetic retinopathy
  • History of heart failure, myocardial infarction, transient ischemic attack or stroke
  • Other diseases that may cause VF loss or optic disc abnormalities
  • Inability to clinically view or photograph the optic discs due to media opacity or poorly dilating pupil
  • Inability to perform reliably on automated VF testing
  • Life-threatening or debilitating illness making it unlikely patient will successfully complete the study.
  • Refusal of informed consent or of commitment to the full length of the study
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01931904

Contact: Janice Ladwig 503-494-8024
Contact: Denny Romfh 503-494-4351

United States, Oregon
OHSU Recruiting
Portland, Oregon, United States, 97239
Contact: Janice Ladwig    503-494-8024   
Contact: Denny Romfh    503-494-4351   
Sub-Investigator: Beth Edmunds, MD, Ph. D.         
Sub-Investigator: Mansi Parikh, MD         
Sub-Investigator: Hana Takusagawa, MD         
Sub-Investigator: Lorinna Lombardi, MD         
Sub-Investigator: David Huang, MD, PhD         
Sub-Investigator: Shandiz Tehrani, MD         
Sponsors and Collaborators
Oregon Health and Science University
Principal Investigator: John Morrison, MD Oregon Health and Science University
  More Information

Additional Information:
Responsible Party: David Huang, John Morrison, MD, Professor of Ophthalmology, Glaucoma Services Director, Oregon Health and Science University Identifier: NCT01931904     History of Changes
Other Study ID Numbers: IRB000009745
1R01EY023285 ( US NIH Grant/Contract Award Number )
Study First Received: August 27, 2013
Last Updated: April 21, 2015

Keywords provided by Oregon Health and Science University:

Additional relevant MeSH terms:
Ocular Hypertension
Eye Diseases processed this record on May 22, 2017