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NCT Number: NCT02896452

Astronaut Vision Issues in a Ground Analog Population: Polycystic Ovary Syndrome

The investigators have documented a genetic predisposition for some astronauts to develop ophthalmologic issues (e.g., choroidal folds, cotton wool spots, optic disc edema). Women with polycystic ovary syndrome (PCOS) have several characteristics similar to those described in astronauts, including: higher homocysteine concentrations, increased incidence of intracranial hypertension, increased retinal nerve fiber layer thickness, increased incidence of white matter hyperintensities on MRI, increased androgen concentrations (or androgen responses to space flight), and indices of altered carbohydrate metabolism. Women with PCOS have not been evaluated in detail regarding the occurrence of other anomalies observed in astronauts including choroidal folds, optic disc edema and cotton wool spots as well as changes in cycloplegic refraction, and optic nerve sheath diameter. While researchers have evaluated one-carbon metabolism pathway polymorphisms re: PCOS, and initial studies show an association with certain one-carbon polymorphisms, none have looked at the complete set of SNPs proposed here. This study will evaluate women with PCOS and/or idiopathic intracranial hypertension (IIH) to assess one-carbon biochemistry and genetics and their possible correlation with ophthalmologic findings. The investigators aim to clarify the relationship of one carbon metabolism and ophthalmic findings in astronauts and patients with PCOS and/or IIH.

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Key information

About this study

Evidence from initial analysis of 5 SNPs in the one-carbon metabolism pathway suggests that one-carbon pathway genes may predict risk of ocular changes and possible vision impairment during and after long-duration space flight. It is not precisely known whether it is these particular genes, or a haplotype of genes that are linked to these genes, that influence risk. Furthermore, ancestry is a strong factor that predicts SNP occurrence in a population, and the association between one-carbon metabolism and the risk of vision-related issues may simply stem from the fact that one particular ancestry has a higher prevalence of these SNPs.

The investigators propose that there are other SNPs in the one-carbon metabolism pathway that alter risk of ocular changes and potential vision impairment during long-duration spaceflight. To that end, extended studies of one-carbon genetics in astronauts have recently been initiated. The investigators hypothesize that the differences between genetic, biochemical, and ophthalmologic findings in PCOS and/or IIH patients and controls will mirror many of the differences found between astronauts who had ophthalmic issues during and after flight.

SPECIFIC AIMS

The key aims of this study are to: a) determine extensive one carbon pathway and related biochemistry, targeted metabolomics, and genetics (523 SNPs of the 85 major genes), and b) conduct ophthalmologic exams on patients in one of four treatment groups:

  • women diagnosed with PCOS without IIH
  • women diagnosed with PCOS and IIH
  • women diagnosed with IIH without PCOS
  • women without PCOS or IIH Participants will be matched by age and body mass index (BMI). Statistical analyses will be used to evaluate the independent and shared contributions of age, body mass (BMI), and genetics on biochemical, and ophthalmologic outcomes, with False Discovery Rate adjustments to account for multiple comparisons.

A secondary aim is to combine the patient and control data from this study with ISS crewmember data in order to help inform us on whether or not these two cohorts (astronauts with ophthalmic issues, PCOS patients) share similar associations among one-carbon metabolism genetics and biochemistry and ophthalmologic data identified in the investigators' earlier analyses.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Clinical diagnosis of PCOS and/or IIH
  • No current medications for the treatment of PCOS
  • Age and BMI-matched healthy women without PCOS or IIH will be used as controls

Exclusion criteria

  • Clinical diagnosis of Cushing's syndrome
  • Untreated hypo/hyperthyroidism, elevated prolactin, congenital adrenal hyperplasia, renal insufficiency or diabetes.
  • Currently taking medications that can affect androgen concentrations or insulin sensitivity.
  • Pregnant, breast-feeding, taking oral contraceptives or currently smoking.
  • Taking medications that affect folate or B12 metabolism, such as methotrexate, trimethoprim, triamterene, phenobarbital, phenytoin, carbamazepine, gabapentin, or primidone or topiramate.

Treatment and study plan

Primary outcomes

  1. Single Nucleotide Polymorphism (SNP) Genetic Testing related to 1-Carbon Metabolism Pathway for 523 SNPs

    Time frame: 1 Day

  2. Ophthalmologic exam -OCT

    Time frame: 1 Day

    Optical coherence tomography test

  3. Ophthalmologic exam -Fundus

    Time frame: 1 Day

    Fundus photography

  4. Ophthalmologic exam - US

    Time frame: 1 Day

    Eye ultrasound exam

  5. Ophthalmologic exam -Vision

    Time frame: 1 Day

    Cycloplegic refraction test

  6. Ophthalmologic exam -IOP

    Time frame: 1 Day

    Intraocular pressure

Secondary outcomes

  1. Questionnaire

    Time frame: 1 Day

    Questions related to birthplace, as well as birthplace of parents and grandparents, if known

  2. B-vitamin Status - folate

    Time frame: 1 Day

    Serum Folate measurement

  3. B-vitamin Status - B12

    Time frame: 1 Day

    Methylmalonic acid

  4. B-vitamin Status - serum B12

    Time frame: 1 Day

    Serum vitamin B-12

  5. Testosterone

    Time frame: 1 Day

  6. Hemoglobin

    Time frame: 1 Day

  7. Plasminogen Activator Inhibitor Antigen

    Time frame: 1 Day

  8. Insulin

    Time frame: 1 Day

  9. Homocysteine

    Time frame: 1 Day

Sponsors and collaborators

Lead sponsor

National Aeronautics and Space Administration

Unknown

Collaborators

  • Coastal Eye Associates
  • Mayo Clinic
  • University of Florida
  • University of North Carolina
  • University of Texas

Registry information

Official study title

Astronaut Vision Issues and One Carbon Metabolism: Expanded Polymorphism Evaluation and Evaluation in a Potential Analog Population

Acronym: PCOS

Important dates

Study start
2016
Primary completion
2020
Study completion
2026
First posted
Sep 12, 2016
Registry last updated
May 22, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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