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

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

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06611670
Acronym
ACTIVESENTRY
Enrollment
31
Registered
2024-09-25
Start date
2025-01-01
Completion date
2026-03-31
Last updated
2026-08-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cataract, Cataract Bilateral, Cataract Surgery

Keywords

Active Sentry, cataract surgery, cataracts, High intra-ocular pressure, central corneal thickness, intraocular pressure, phacoemulsification, safety profile, physiological IOP

Brief summary

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.

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.

Interventions

DEVICECataract surgery with Active Sentry

Surgical instrument that detects changes in intraocular pressure and allows rapid feedback to stabilize pressure during cataract surgery.

Cataract surgery performed with high intraocular pressures

Sponsors

Centre hospitalier de l'Université de Montréal (CHUM)
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Intervention model description

Interventional single-masked pair-eye design clinical trial, single-center, single-surgeon. Eyes will be block-randomized as to which surgery they will receive first (high vs low IOP phacoemulsification). 62 eyes of 31 patients will be included in this study. For each patient, one eye will be randomized to receive phacoemulsification with high IOP (Group 1), and the other eye will receive phacoemulsification with physiological IOP (Group 2). This way, each patient will receive both treatments, one for each eye, which will allow us to do paired analyses.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

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.

Design outcomes

Primary

MeasureTime frameDescription
Central corneal thickness at 1 day postoperatively1 day postoperativelyUsing 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).

Secondary

MeasureTime frameDescription
Volume of balanced salt solution used during surgeryDuring surgeryVolume of balanced salt solution as measured by the Active Sentry Centurion machine
Total ultrasound time and total aspiration timeDuring surgeryTotal ultrasound time and total aspiration time as measured by the Active Sentry Centurion machine
Endothelial cell loss (inner surface of the cornea)At month 1 and month 3 postoperatively.Endothelial cell count measured by specular microscopy
Central corneal thickness1 week, 1 month and 3 months postoperativelyUsing 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).
Corneal clarityDay 1, week 1, month 1 and month 3 postoperativelyMeasured uring the Pentacam corneal densitometry

Countries

Canada

Contacts

PRINCIPAL_INVESTIGATORSamir Jabbour, MD,CM,FRCSC

Centre hospitalier de l'Université de Montréal (CHUM)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 15, 2026