Effect of Topical Phenylephrine 2.5% on EVP in Normal Human Eyes


  • Study type

  • Study IDs

  • Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • Site IRB
    • Rochester, Minnesota: 16-007077
    NCT ID: NCT02965924
    Sponsor Protocol Number: 16-007077

About this study

Phenylephrine hydrochloride ophthalmic solution is an alpha-1 adrenergic receptor agonist commonly used topically for dilation prior to ocular fundus examination. In the eye, phenylephrine acts locally as a potent vasoconstrictor and mydriatic by constricting ophthalmic blood vessels and the radial dilator muscle of the iris. Episcleral venous pressure (EVP) is a determinant of intraocular pressure (IOP) and can be measured non-invasively by venomanometry. Since phenylephrine is a vasoconstrictor, it may affect episcleral venous tone, but the effect on EVP is unknown. Understanding the physiology of episcleral veins helps us in better understanding of pathophysiology of glaucoma.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

Inclusion Criteria:

  • Any self-declared ethno-racial category.
  • Medically healthy subjects.
  • Subjects with two healthy eyes.
  • Intraocular pressure (IOP) less than 22 mmHg in each eye.
  • Best-corrected visual acuity (BCVA) in each eye 20/50 or better.
  • Open angles in both eyes.
  • Contact lens wear stopped at least 3 days prior to study, and during the study.
  • Ability to cooperate for examinations required for study.

Exclusion Criteria:

  • Chronic or acute ophthalmic diseases including glaucoma, wet type macular degeneration, uveitis and clinically significant cataract.
  • Evidence of ocular infection, inflammation, clinically significant blepharitis or conjunctivitis.
  • Cornea pathologic changes preventing reliable measurement.
  • Narrow anterior chamber angle.
  • Previous intraocular surgeries, laser procedures, and intravitreal injections.
  • Previous corneal refractive surgeries.
  • Myopia greater than -6.00 D spherical equivalent.
  • Hyperopia greater than +2.00 D spherical equivalent.
  • Lack of suitable episcleral vein for measurement.
  • Ocular trauma within the past 6 months.
  • Ocular infection or ocular inflammation in the past 3 months.
  • Ocular medication of any kind within 30 days of study visit.
  • Known hypersensitivity to Phenylephrine or topical anesthetic medication.
  • Severe hypertension: Systolic blood pressure greater than 180 mmHg and/or diastolic blood pressure greater than 105 mmHg.
  • A known history of ischemic heart disease (angina or myocardial infarction), cerebrovascular accidents, cardiac arrhythmias, cerebral or aortic aneurysms.
  • Uncontrolled diabetes mellitus.
  • Uncontrolled hyperthyroidism.
  • Use of some systemic medications within 30 days prior to study including: β-adrenergic antagonists, α-adrenergic agonists and antagonists, calcium channel blockers, diuretics, vasodilators, monoamine oxidase inhibitors, and systemic steroids.
  • Participation in any interventional study within the past 30 days prior to study visit.
  • Women who are pregnant.

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Arthur Sit, M.D.

Closed for enrollment

Contact information:

Jane Sultze




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