Outcomes of High vs Physiological Intraocular Pressure During Cataract Surgery Using ACTIVE SENTRY (ACTIVESENTRY)

August 13, 2026 updated by: Centre hospitalier de l'Université de Montréal (CHUM)
Cataract surgery is a widely performed procedure across the world that helps restore vision in many patients suffering from cataracts. Irrigation is an essential component of the surgery. Fluid is constantly circulated to help regulate temperature as heat is generated with ultrasound energy, to minimize tissue trauma, and to create an intraocular pressure (IOP) sufficient to keep the anterior chamber (AC) stable. In parallel, aspiration brings the components of the cataract closer to the surgical instrument. A balance between irrigation and aspiration during surgery is essential to maintain stability in the AC. However, an ideal flow rate, which influences IOP during surgery, is yet to be determined. Most recent studies with Centurion Active Sentry show that there is similar efficiency between higher and lower IOP settings. Traditionally, high-flow rates have been used in advanced cataracts and are believed to make space in the AC. However, they are known to create fluid turbulence and are associated with risks of tissue damage, including cell loss in one of the cornea's layers. High IOP during surgery has also been shown to cause damage to the optic nerve as well as to the retina. Distorting and stretching the AC during phacoemulsification have also been associated with increased pain experienced by the patient. Comfort can be achieved by lowering pressure levels. Low-flow rates have a better safety profile, reduce IOP and pressure fluctuations while offering equal efficiency, including comparable surgical time. Using central corneal thickness (CCT) as an indicator of corneal trauma, it has been shown that patients that have had surgery with low-flow rates present no change in the CCT postoperatively as opposed to patients in the high-flow rates. As less fluid turbulence is created with low-flow rates, there is decreased risk of fragment contact with the cornea's inner surface, thus reducing cell loss. Alcon Laboratories, Inc. developed Active Fluidics which allows to stabilize intraocular pressure and prevent IOP fluctuations as well as IOP surges during surgery. It is now further equipped with the Active Sentry handpiece which is integrated to the surgical instrument and acts as a sensor to pressure variation. It allows rapid feedback to maintain a stable AC. Our research project aims to assess the outcomes following phacoemulsification done with physiological IOP with the help of the Active Sentry handpiece compared to traditional high IOP levels.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Cataract surgery is a widely performed procedure across the world that helps restore vision in many patients suffering from cataracts. The surgery has known many improvements across time and continues to do so. Irrigation is an essential component of the surgery. Fluid is constantly being circulated to help regulate temperature as heat is generated with the use of ultrasound energy, to minimize tissue trauma, and to create an intraocular pressure sufficient to keep the anterior chamber stable. In parallel, aspiration brings the components of the cataract closer to the surgical instrument. A balance between irrigation and aspiration during surgery is essential to maintain stability in the anterior chamber. However, an ideal flow rate, which influences intraocular pressure (IOP) during surgery, is yet to be determined. Most recent studies with Centurion Active Sentry (maintaining vacuum and aspiration rates the same) show that there is similar efficiency between higher and lower IOP settings. Traditionally, high-flow rates have been used in advanced cataracts and are believed to increase the space in the anterior chamber. However, they are known to create fluid turbulence and are associated with risks of tissue damage, including cell loss in the endothelial layer of the cornea. High intra-ocular pressure during surgery has also been shown to cause damage to the optic nerve as well as to the retina. Distorting and stretching the anterior chamber during phacoemulsification have also been associated with increased pain experienced by the patient. Comfort can be achieved by lowering pressure levels. Low-flow rates have a better safety profile, reduce IOP and pressure fluctuations while offering equal efficiency, including comparable surgical time. Using central corneal thickness (CCT) as an indicator of corneal trauma, it has been shown that patients that have had surgery with low-flow rates present no change in the CCT postoperatively while patients in the high-flow rates show signs of corneal damage as well as greater anterior segment inflammation. As less fluid turbulence is created with low-flow rates, there is decreased risk of fragment contact with the cornea's inner surface, thus reducing cell loss. Alcon Laboratories, Inc. developed Active Fluidics which allows to stabilize intraocular pressure and prevent IOP fluctuations as well as IOP surges during surgery. It is now further equipped with the Active Sentry handpiece which is integrated to the surgical instrument and acts as a sensor to pressure variation. It allows rapid feedback to maintain a stable anterior chamber. Our research project aims to assess the outcomes following phacoemulsification done with physiological IOP with the help of the Active Sentry handpiece compared to traditional high IOP levels.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
31

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Canada
    • Quebec
      • Montreal, Quebec, Canada
        • Centre Hospitalier de l'Université de Montréal

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • No prior ocular surgery including corneal refractive surgery
  • Bilateral visually significant cataract, similar in density (LOCS III grade 2+), undergoing uncomplicated cataract surgery
  • Equal dilated pupil size ≥6mm, no use of pupil expansion devices
  • Axial length 21-26mm, refractive error between -8.00D to +6.00D and cylinder ≤ 4.50D, normal K values <48.00D
  • Normal CCT range 540µm ± 50

Exclusion Criteria:

  • History of corneal disease or dystrophies
  • Media opacification for reasons other than cataract
  • Compromised zonular integrity or stability.
  • Retinal and retinal vascular pathologies, age-related macular degeneration
  • Glaucoma
  • Patients with uncontrolled systematic diseases, including hypertension, diabetes, systemic cardiovascular diseases, and hematological diseases.

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: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Cataract surgery with Active Sentry
Cataract surgery with low IOP values (32mmHg)
Device: Cataract surgery with Active Sentry
Surgical instrument that detects changes in intraocular pressure and allows rapid feedback to stabilize pressure during cataract surgery.
Active Comparator: High IOP
Cataract surgery with high IOP (60mmHg) which is the average pressure at which cataract surgery is being performed currently
Procedure: Traditional cataract surgery
Cataract surgery performed with high intraocular pressures

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Central corneal thickness at 1 day postoperatively
Time Frame: 1 day postoperatively
Using central corneal thickness (CCT) as an indicator of corneal trauma, it has been shown that patients that have had surgery with low-flow rates present no change in the CCT postoperatively. CCT will be measured using a pachymetry (Normal CCT range 540µm ± 50).
1 day postoperatively

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Volume of balanced salt solution used during surgery
Time Frame: During surgery
Volume of balanced salt solution as measured by the Active Sentry Centurion machine
During surgery
Total ultrasound time and total aspiration time
Time Frame: During surgery
Total ultrasound time and total aspiration time as measured by the Active Sentry Centurion machine
During surgery
Endothelial cell loss (inner surface of the cornea)
Time Frame: At month 1 and month 3 postoperatively.
Endothelial cell count measured by specular microscopy
At month 1 and month 3 postoperatively.
Central corneal thickness
Time Frame: 1 week, 1 month and 3 months postoperatively
Using central corneal thickness (CCT) as an indicator of corneal trauma, it has been shown that patients that have had surgery with low-flow rates present no change in the CCT postoperatively. CCT will be measured using a pachymetry (Normal CCT range 540µm ± 50).
1 week, 1 month and 3 months postoperatively
Corneal clarity
Time Frame: Day 1, week 1, month 1 and month 3 postoperatively
Measured uring the Pentacam corneal densitometry
Day 1, week 1, month 1 and month 3 postoperatively

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Visual acuity
Time Frame: Day 1, week 1, month 1, and month 3 postoperatively
Evaluated using a Snellen chart
Day 1, week 1, month 1, and month 3 postoperatively
Low contrast evaluation
Time Frame: Day 1, week 1, month 1, and month 3 postoperatively
Evaluated using the CSV-1000 Contrast Sensitivity chart with glare
Day 1, week 1, month 1, and month 3 postoperatively
Intraocular pressure
Time Frame: Day 1, week 1, month 1, and month 3 postoperatively
Measured using the Goldmann Applanation Tonometer
Day 1, week 1, month 1, and month 3 postoperatively
Cystoid macular edema
Time Frame: 1 month postoperatively
Evaluated using the Macular Optical Coherence Tomography (OCT)
1 month postoperatively
Rate of reverse pupillary block
Time Frame: 1 day, 1 week, 1 month and 3 months postoperatively
Evaluated using slit lamp examination
1 day, 1 week, 1 month and 3 months postoperatively
Posterior capsular tear
Time Frame: During surgery
Complication during cataract surgery
During surgery
Posterior capsular rupture
Time Frame: During surgery
Complication during cataract surgery
During surgery

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Centre hospitalier de l'Université de Montréal (CHUM)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Samir Jabbour, MD,CM,FRCSC, Centre hospitalier de l'Université de Montréal (CHUM)

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.

General Publications

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 31, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 22, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 22, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 25, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2025-11959

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

No

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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