This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Systemic Glutathione Level in Normal Tension Glaucoma

This study has been completed.
Information provided by:
The Catholic University of Korea Identifier:
First received: December 7, 2007
Last updated: July 14, 2010
Last verified: December 2007
The purpose of this study is to evaluate whether systemic glutathione level is decreased in patients with normal tension glaucoma.

Normal Tension Glaucoma

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Cross-Sectional
Official Title: Evaluation of Systemic Glutathione Level in Patients With Normal Tension Glaucoma

Resource links provided by NLM:

Further study details as provided by The Catholic University of Korea:

Primary Outcome Measures:
  • Total Glutathione Levels [ Time Frame: Once in the morning. ]
    Subjects were instructed to fast from midnight to 8 AM on the morning of the test. All blood samples were obtained by a qualified registered nurse in the morning, between 8 and 10 AM.

Biospecimen Retention:   Samples Without DNA

Enrollment: 49
Study Start Date: March 2008
Study Completion Date: October 2008
Primary Completion Date: October 2008 (Final data collection date for primary outcome measure)
Detailed Description:

Normal tension glaucoma is one of the most common cause of primary open angle glaucoma in Korea. Even though, we still do not know what the cause is. Only IOP-lowering drugs are the currently available therapeutic method. Glutathione is one of the mostly high concentrated intracellular antioxidants. We find apoptosis of neuronal cell in the mouse retina by systemic depletion of glutathione using buthionine sulfoximine. Glutathione is also known to be reduced in primary open angle glaucoma with high IOP. So we are planning to evaluate systemic glutathione level in normal tension glaucoma.

Blood samples will be obtained by venipuncture to the antecubital vein of normal tension glaucoma patients and age-matched normal controls. Five milliliters of blood will be collected in EDTA-treated tubes (to prevent oxidation). Thirty microliters of blood will be then transferred into centrifuge tubes, and will be added 33.3 microliter of 5-sulfosalicylic acid (SSA), 100mg/mL within 10 minutes from the blood collection.Each sample will be then diluted with 936.7 microliter sodium phosphate buffer (pH 7.5), and the content of each tube will be mixed rapidly in a centrifuge at 13,000 rpm for 5 minutes. A portion of supernatant (150 microliter) will be then collected into clean centrifuge tubes and immediately cooled at -70°C. To each well of a 96-well plate, 150 microliter of daily buffer (3 mg NADPH into 10 mL sodium phosphate buffer), 50microliter of DTNB solution, and 25 microliter of standards or samples will be added in quadruplicate, and the plate will be incubated at 37 °C for 3 minutes.Finally, 25 microliter GSSGR will be added to the previous mixture, and the plate will be read at 410 nm using a 96-well plate reader(UV spectrophotometer).


Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
patients of tertiary referred center

Patients were included in the normal tension glaucoma group according to the following criteria.

Inclusion Criteria (normal tension glaucoma group):

  • Clinical Diagnosis of Normal Tension Glaucoma: Patients underwent diurnal IOP phasing and were diagnosed as having normal tension glaucoma(IOP always lesser than 22 mm Hg by applanation tonometry), glaucomatous optic disc cupping on fundoscopic examination, open anterior chamber angles by gonioscopy(Schaffer grade III or more), and repeatable VF defects consistent with the diagnosis of glaucoma, according to results obtained with program 24-2 of the Humphrey Field Analyzer.
  • Must be able to provide intravenous blood sampling

Exclusion Criteria (normal tension glaucoma group):

  • Narrow iridocorneal angles
  • Any evidence of secondary open-angle glaucoma
  • Any other ocular disease except cataract
  • History of previous intraocular surgery including cataract
  • Any other systemic disease except hypertension

The control group was composed of age-matched healthy volunteers who had neither glaucoma nor other ocular diseases such as cataract, diabetic retinopathy or age related macular degeneration. The control group did not show any glaucomatous optic disc cupping on fundoscopic examination or visual field defects with program 24-2 of the Humphrey Field Analyzer. The healthy volunteers in the control group must be able to provide intravenous blood sampling.

Exclusion criteria for both groups:

  • Smoking
  • History of any chronic systemic disease with presumed low glutathione levels, including autoimmune diseases, alcoholic liver disease, cancer, and diabetes mellitus.
  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: NCT00570362

Korea, Republic of
College of Medicine, The Catholic University of Korea, St. Mary's Hospital
Seoul, Korea, Republic of, 150-713
Sponsors and Collaborators
The Catholic University of Korea
Study Director: Jung-Il Moon, Professor Department of Ophthalmology, St.Mary's Hospital, College of Medicine, The Catholic University of Korea
  More Information

Responsible Party: Jung-Il Moon, St.Mary's Hospital, College of Medicine, The Catholic University of Korea Identifier: NCT00570362     History of Changes
Other Study ID Numbers: Merck-001
Study First Received: December 7, 2007
Results First Received: June 11, 2010
Last Updated: July 14, 2010

Keywords provided by The Catholic University of Korea:
Normal tension glaucoma

Additional relevant MeSH terms:
Low Tension Glaucoma
Ocular Hypertension
Eye Diseases
Optic Nerve Diseases processed this record on September 18, 2017