Measuring the Effects of Netarsudil, Latanoprost, and Combination Therapy on Episcleral and Retinal Blood Flow in Ocular Hypertension and Glaucoma Suspects

June 30, 2026 updated by: Osamah Saeedi, University of Maryland, Baltimore

Measuring the Effects of Netarsudil, Latanoprost, and Combination Therapy on Episcleral and Retinal Blood Flow in Ocular Hypertension and Glaucoma Suspects Using Erythrocyte Mediated Angiography In Vivo

The goal of this clinical trial is to compare participants treated with latanoprost to those treated with Rocklatan (netarsudil/latanoprost) to determine whether the addition of netarsudil results in greater improvements in episcleral venous blood flow in adults with glaucoma or ocular hypertension. Episcleral venous blood flow will be measured using erythrocyte-mediated angiography (EMA) and laser speckle contrast imaging (LSCI).

The main questions this study aims to answer are:

  • Does Rocklatan produce greater increases in episcleral venous blood flow than latanoprost alone?
  • Can EMA and LSCI reliably detect changes in episcleral venous blood flow following treatment with these medications?

Participants will:

  • Be randomized to receive either latanoprost or Rocklatan
  • Undergo imaging of the episcleral veins using EMA and LSCI before, during, and after treatment, and
  • Complete study visits that include standard ophthalmic examinations and intraocular pressure measurements.

Hypothesis: The investigators hypothesize that latanoprost, which primarily increases uveoscleral outflow, will not significantly affect the distal episcleral circulation. In contrast, Rocklatan, through its netarsudil component, is expected to produce measurable increases in episcleral venous flow.

Study Overview

Detailed Description

Glaucoma is a leading cause of irreversible blindness worldwide, and lowering intraocular pressure (IOP) remains the primary strategy for slowing disease progression. While many glaucoma medications reduce IOP by increasing aqueous humor outflow or decreasing its production, the effects of these therapies on the distal conventional outflow pathway-particularly the episcleral venous circulation-are not well understood. Previous studies using erythrocyte-mediated angiography (EMA)-a novel imaging technique capable of directly quantifying episcleral venous blood flow in vivo-demonstrated that netarsudil (Rhopressa) significantly increases episcleral venous flow while lowering IOP, supporting episcleral blood flow as a biomarker of distal outflow function.

This study will build on those findings by comparing the effects of latanoprost and Rocklatan (netarsudil/latanoprost) on episcleral venous blood flow using both EMA and laser speckle contrast imaging (LSCI), a newer, less invasive imaging modality. Investigators will evaluate whether the addition of netarsudil to latanoprost produces measurable improvements in episcleral venous flow beyond those achieved with latanoprost alone. By improving the understanding of how these medications influence the distal outflow pathway, this study may help explain the superior IOP-lowering efficacy of Rocklatan and support the development of noninvasive imaging methods for assessing treatment response in glaucoma.

Building on these findings, this study will compare the effects of latanoprost and Rocklatan (netarsudil/latanoprost) on episcleral venous blood flow using EMA and laser speckle contrast imaging (LSCI), a newer, noninvasive imaging modality. Latanoprost, a first-line prostaglandin analogue, primarily lowers IOP by increasing uveoscleral outflow and is not expected to substantially alter distal episcleral circulation. In contrast, Rocklatan combines the effects of latanoprost with netarsudil, which enhances conventional outflow and reduces episcleral venous pressure, and is therefore hypothesized to produce measurable increases in episcleral venous blood flow. By directly comparing these therapies, the study aims to assess whether Rocklatan enhances distal outflow as compared to latanoprost, correlate changes in episcleral flow with IOP reductions to evaluate the role of episcleral modulation as a driver of Rocklatan's enhanced clinical efficacy, and redefine how researchers and clinicians evaluate IOP-lowering therapies by targeting the actual vascular response of the distal outflow system.

Ultimately, this work has the potential to clarify the mechanism underlying Rocklatan's superior efficacy, establish episcleral venous flow as a novel biomarker for pharmacologic response, and support further development of therapies that leverage distal outflow enhancement.

Study Type

Interventional

Enrollment (Estimated)

50

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Maryland
      • Baltimore, Maryland, United States, 21201
      • Baltimore, Maryland, United States, 21201
      • Columbia, Maryland, United States, 21045
        • Recruiting
        • UM Faculty Physicians, Inc. | 5900 Waterloo Crossing
        • Principal Investigator:
          • Osamah Saeedi, MD
        • Contact:
          • Osamah Saeedi, MD
          • Phone Number: 410-328-3865
      • Silver Spring, Maryland, United States, 20902
        • Recruiting
        • Maryland Eye Consultants and Surgeons
        • Principal Investigator:
          • Osamah Saeedi, MD
        • Contact:
          • Osamah Saeedi

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 88 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Study Population

Subjects will be recruited from the optometry service and the glaucoma division at the University of Maryland School of Medicine, Department of Ophthalmology. We will establish a cohort of 10 patients comprised of treatment-naïve ocular hypertensive and glaucoma suspect patients with the following eligibility criteria.

Description

Inclusion:

  • Patients are at least 18 years of age.
  • Patients must have ocular hypertension or be a glaucoma suspect.
  • Patient must not have used any IOP-lowering medication (topical or systemic) within the past 6 months
  • Patients must have open angles on gonioscopy.
  • All patients will have at least one recorded visual field examination within 6 months of enrollment in the study. Visual fields will be assessed using the Hodapp-Andersen-Parish criteria.

Exclusion:

  • Participation in other investigational studies, unless such participation does not involve the administration of any drugs or agents that could impact the results of this study or have an effect on episcleral flow, as determined by the Investigator.
  • Prior intraocular surgery other than uncomplicated cataract surgery.
  • Allergy or history of adverse reaction to ICG, shellfish, or Iodine.
  • Significant liver disease or uremia.
  • Secondary glaucoma including exfoliation glaucoma, pigmentary glaucoma, or history of acute angle closure.
  • Moderate or severe visual field deficits as per Hodapp-Anderson-Parish criteria.
  • Any condition precluding imaging including reliable visual fields, disc photography, or use of study treatments including media opacity or tilted optic disk
  • Pregnant or nursing patients.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Glaucoma Suspect
Individuals with a diagnosis of glaucoma suspect
Rocklatan (Netarsudil 0.02%/ latanoprost 0.005) one drop nightly for 14-28 days, if randomized to Rocklatan after 28-35 days on Latanoprost.
Latanoprost 0.005% one drop nightly for 28-35 days, then 14-28 days if randomized to continue on latanoprost.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Episcleral Venous Blood Flow Measured by Erythrocyte-Mediated Angiography (EMA)
Time Frame: Baseline (T0), 28-35 days from baseline (T1), 14-28 days from T1 (T2)
Change in episcleral venous blood flow following treatment with latanoprost 0.005% and/or Rocklatan, as measured by erythrocyte-mediated angiography (EMA). EMA will be used to quantify episcleral blood flow through measurement of erythrocyte velocity and vessel diameter, allowing calculation of absolute blood flow at baseline (T0), after 28-35 days of latanoprost treatment (T1), and after an additional 14-28 days of either continued latanoprost or switching to Rocklatan (T2).
Baseline (T0), 28-35 days from baseline (T1), 14-28 days from T1 (T2)
Change in Retinal Arteriolar and Venular Blood Flow Measured by Erythrocyte-Mediated Angiography (EMA)
Time Frame: Baseline (T0), 28-35 days from baseline (T1), 14-28 days from T1 (T2)
Change in retinal blood flow within arterioles and venules less than 100 microns in diameter following treatment with latanoprost 0.005% and/or Rocklatan, as measured by erythrocyte-mediated angiography (EMA). EMA will be used to quantify retinal blood flow through measurement of erythrocyte velocity and vessel diameter at baseline (T0), after 28-35 days of latanoprost treatment (T1), and after an additional 14-28 days of either continued latanoprost or switching to Rocklatan (T2).
Baseline (T0), 28-35 days from baseline (T1), 14-28 days from T1 (T2)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Osamah Saeedi, MD, University of Maryland, Baltimore

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 2, 2026

Primary Completion (Estimated)

March 17, 2027

Study Completion (Estimated)

March 17, 2027

Study Registration Dates

First Submitted

May 20, 2020

First Submitted That Met QC Criteria

May 20, 2020

First Posted (Actual)

May 26, 2020

Study Record Updates

Last Update Posted (Actual)

July 2, 2026

Last Update Submitted That Met QC Criteria

June 30, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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