Severe Night Vision Disturbance Single-Dose Phase 2 Clinical Trial with Nyxol

About the Trial

Single Dose Study of Phentolamine Mesylate Eye Drops in Patients With Severe Night Vision Disturbances (NCT04004507)

Double-masked, placebo-controlled, single-dose Phase 2 study in 24 patients experiencing severe night vision difficulties to evaluate ocular and systemic safety and efficacy following administration of one drop of phentolamine mesylate 1.0% QD in each eye for 1 day.

Detailed Info

The objectives of this study are:* To assess the effect of ophthalmic phentolamine mesylate in mesopic conditions on the four endpoints: 1. Contrast sensitivity 2. Low contrast visual acuity 3. Wavefront aberrometry 4. Subjective questionnaire * To assess the safety of ophthalmic phentolamine mesylate

Study Phase

Phase 2

Estimated Enrollment


Estimated Primary Completion Date

October, 2007

Study Type


  • Drug: Phentolamine Mesylate Ophthalmic Solution 1%
  • Other: Phentolamine Mesylate Ophthalmic Solution Vehicle (Placebo)

Ocuphire Pharma, Inc.


Inclusion Criteria




18 years and older

  • Currently experiencing severe night vision difficulty as reported subjectively
  • At least two patches below the normal range at any two frequencies in Contrast Sensitivity done under mesopic conditions with glare
  • Improvement in low contrast visual acuity (LCVA) in dim light during illumination of contralateral eye
  • Good general health
  • Written informed consent to participate in this trial
  • Ability to comply with all protocol mandated procedures and to attend all scheduled office visit

Exclusion Criteria

  • Patients with untreated cataracts grades 1-4
  • Patients who wear contact lenses
  • Less than 5 weeks post-refractive surgery (LASIK or PRK)
  • Less than 5 weeks post intraocular lens insertion
  • Low blood pressure (systolic <120 mm Hg or diastolic <80 mm Hg)
  • A history of heart rate abnormalities
  • Administration of any investigational drug within 30 days of study initiation
  • Use of any eye drops with a pharmacologic effect on the pupil within 7 days of Visit 1
  • Use of any systemic alpha adrenergic antagonists (Appendix 1)
  • Known local or systemic hypersensitivity to adrenergic antagonists
  • For women of childbearing potential: currently pregnant or lactating, or unwilling to use birth control during the study


The following cities were clinical trial sites.