Aqueous Humor Dynamic Components That Determine Intraocular Pressure Variance

January 17, 2024 updated by: Sayoko Moroi, Ohio State University
Glaucoma is a major cause of blindness. The inability to predict a patient's IOP response to medications is a critical barrier for the clinician to consistently provide highly effective IOP-based treatments. Current trial-and-error approaches to glaucoma management are inefficient and have not addressed this barrier as there are no predictive factors for drug response. Our long-term goal is to improve outcomes by identifying biomarkers and environmental factors that profile a patient at risk for glaucoma by age-of-onset, rate of disease progression, "poor response" to treatment, and large IOP fluctuation. Our purpose of this research project is to address this critical barrier by focusing on physiological factors that predict IOP response to drugs.

Study Overview

Detailed Description

This proposal responded to PA-18-351 "Human Subjects Mechanistic and Minimal Risk Studies" and qualifies as a clinical trial. The central hypothesis is that variations in IOP response to glaucoma drugs and IOP fluctuation can be predicted by the aqueous humor dynamic (AHD) factors that regulate IOP. This hypothesis will be tested in up to 200 participants with ocular hypertension (OHT) or open-angle glaucoma (OAG). This hypothesis will be tested in two aims: Aim 1, Test the hypothesis that AHD factors predict the IOP drug response; Aim 2, Test the hypothesis that aqueous flow and outflow facility predict IOP fluctuation.

The objective is to determine which AHD factors predict a participant's IOP drug response and IOP fluctuation. The scientific rationale is that AHD parameters (aqueous flow, outflow facility, episcleral venous pressure, and uveoscleral flow) determine drug response and IOP fluctuation.

The primary endpoint is IOP response to glaucoma drugs. Exploratory outcome measures include IOP fluctuation and the AHD measures.

The study population includes participants who have either OHT or OAG. The inclusion and exclusion criteria described in 5.3, Study Population. The goal is to recruit 150-200 participants over 4 years.

All drugs and instruments used in this study have been FDA approved.

Three sites will enroll participants: Mayo Clinic, The Ohio State University, and University of Nebraska Medical Center. All sites have experience and expertise with AHD studies in humans. These study team members have productive collaborations during AHD studies in controls during the prior NIH funding period. There are no sites outside of the United States.

The experimental design is a prospective, open-label, clinical trial with randomized cross over treatment using the topical glaucoma medications, timolol 0.5% and latanoprost 0.005%. Timolol 0.5% is a beta-blocker and will be dosed as one drop two times a day. Latanoprost 0.005% is a prostaglandin analogue and will be dosed as one drop daily in the evening. The treatment order will depend on randomization.

AHD measurements are performed at baseline without glaucoma medications. The AHD measurements include IOP, aqueous humor flow, outflow facility, and episcleral venous pressure. Uveoscleral outflow is calculated. Some participants who are already taking glaucoma medications will be washed out in order to assess baseline AHD measurements. An IOP safety check will be scheduled for those who are washed out of their glaucoma Rx. After baseline AHD measurements, the AHD measurements are repeated after each of the 7-day drug interventions to determine the effect of the drug treatment on AHD variables.

There are six study visits, Visits 1 - 6, that include clinical testing, surveys, and AHD procedures (see 1.2 Schema). Participants will be trained to use the Icare® HOME tonometer to measure IOP outside of clinic to assess IOP fluctuation.

The study design is a prospective, open-label, randomized order of 7-days treatments with timolol 0.5% (1 drop two times daily) followed by a washout period and then with latanoprost 0.005% (1 drop daily in the evening) or vice versa. These are referred to as Tx 1 and Tx 2. IOP safety checks during washout are included for those already taking glaucoma Rx upon entering the study. IOP response will be determined to each of these medications. AHD factors will be determined for both study treatments using tonometry, fluorophotometry, tonography, and episcleral venomanometry. IOP fluctuation will be assessed using the FDA-approved Icare® HOME tonometer. All test procedures and drugs are FDA approved. There are no experimental tests or agents.

Sample sizes and power calculations provide rigor to test the hypothesis.

A REDCap database is populated from data on case report forms (CRF), surveys, and the Icare® HOME tonometer. Data will be analyzed using descriptive statistics of central tendencies and dispersion, and regression methods in order to understand the individual data in the distribution of the cohort.

Study Type

Interventional

Enrollment (Estimated)

100

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

    • Minnesota
      • Rochester, Minnesota, United States, 55905
    • Nebraska
      • Omaha, Nebraska, United States, 68105
        • Recruiting
        • University Of Nebraska Medical Center
        • Contact:
        • Contact:
    • Ohio
      • Columbus, Ohio, United States, 43212

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

30 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Any self-declared ethnicity-race
  • Open-angle with one of the following:

    1. Untreated OHT ≥ 21mmHg
    2. Treated OHT with history of IOP ≥ 21 mmHg on 2 prior clinic visits or IOP ≥ 21 mmHg at screening
    3. Mild-to-moderate stage open-angle glaucoma based on history of untreated IOP ≥ 21 mmHg
  • Reliable Humphrey visual field test result within previous 1 year
  • Open on gonioscopy within previous 1 year
  • At least one eye must be phakic
  • Able to cooperate for aqueous humor dynamic procedures
  • Able to participate on site over the multi-visit study period
  • Contact lenses must be removed before topical fluorescein instillation and remain out until study testing the following day is completed.
  • Contact lenses must be removed for the entire duration of the study visits.
  • All study medication must be used without contact lenses in the eyes.

Exclusion Criteria:

  • Women who are pregnant or breastfeeding
  • IOP ≥ 38 in study eye(s) or at discretion of the clinician
  • Refusal to remove contact lenses
  • Advanced visual field loss (MD ≤ -16 dB) or threat to fixation in study eye(s) or at discretion of the clinician
  • Study eye(s) with any sign of Fuchs cornea dystrophy as noted clinically with guttae and corneal edema
  • Narrow angle of ≤ Shaffer grade 2 for 180 degrees, peripheral synechiae, or peripheral iridotomy in either eye
  • History of acute angle closure crisis in either eye
  • History of glaucoma incisional surgery (e.g., trabeculectomy, glaucoma drainage implant, Xen gel stent) in study eye(s)
  • History of minimally invasive glaucoma surgery (MIGS, e.g., angle surgery, Cypass) in study eye(s)
  • History of any cycloablation surgery (e.g., micropulse or diode transcleral or endoscopic cyclophotocoagulation) in study eye(s)
  • Study eye cannot have history of any past SLT or ALT glaucoma laser treatments.
  • Study eye(s) cannot have any history of refractive surgery
  • Study eye(s) cannot have any history of herpetic infection of the cornea
  • Study eye(s) cannot have chronic or recurrent inflammatory eye disease
  • Study eye(s) cannot have ocular trauma within the past 6 months, other than uncomplicated cornea abrasion
  • Study eye(s) cannot have ocular infection in the past 3 months
  • Study eye(s) cannot have clinically significant retinal disease that includes proliferative diabetic retinopathy, vein occlusion, cystoid macular edema, wet age-related macular degeneration
  • History of intraocular or peri-ocular injections in study eye(s) within 3 months
  • History of oral steroid use within 30 days of screening Visit 1
  • Any abnormality preventing reliable fluorophotometry (e.g., corneal scarring or severe dry eye with fluorescein staining)
  • Serious hypersensitivity to any components of study medications or risk from treatment (e.g., sulfa drug allergy, bradycardia, severe asthma, or emphysema)
  • Participants must be on minimum 30-day stable regimen prior to Visit 1 for a systemic medication that may affect IOP (i.e., sympathomimetics, beta-blockers, alpha-adrenergic agonists and blockers, calcium channel blockers, angiotensin converting enzyme inhibitors, etc.). Any change of such medication during the study will result in exclusion.
  • Prohibited meds during study: cannabis products, brimonidine 0.025% (Lumify), bimatoprost 0.03% for eyelash growth (Latisse), topical ocular and peri-ocular steroids, oral steroids

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Timolol 0.5%
To compare the variation in response to timolol between individuals
1 drop BID
Experimental: Latanoprost 0.005%
To compare the variation in response to latanoprost between individuals
1 drop QD

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Variation in eye pressures between individuals
Time Frame: measurement after 1 week of treatment
Eye pressure is a steady state quantitative trait that is measured in mm Hg. Eye pressure is determined by the following physiological factors (units of measure): eye fluid or aqueous humor production (microliters/minute), aqueous humor outflow (microliters/minute), outflow resistance (microliters/minute/mm Hg) and venous pressure (mm Hg) of the eye. All of these physiological factors will be determined under baseline condition and under glaucoma drug treatment.
measurement after 1 week of treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Variation in aqueous flow between individuals
Time Frame: measurement 1 week after treatment
Aqueous flow production (microliters/minute) will be determined under baseline condition and under glaucoma drug treatment.
measurement 1 week after treatment
Variation in episcleral venous pressure
Time Frame: measurement 1 week after treatment
Episcleral venous pressure (mm Hg) of the eye will be determined under baseline condition and under glaucoma drug treatment.
measurement 1 week after treatment

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Sayoko Moroi, MD, PhD, Professor and Chair

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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 (Actual)

November 23, 2020

Primary Completion (Estimated)

July 1, 2024

Study Completion (Estimated)

August 31, 2024

Study Registration Dates

First Submitted

May 29, 2020

First Submitted That Met QC Criteria

May 29, 2020

First Posted (Actual)

June 2, 2020

Study Record Updates

Last Update Posted (Estimated)

January 19, 2024

Last Update Submitted That Met QC Criteria

January 17, 2024

Last Verified

January 1, 2024

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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.

No

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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