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

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: Not yet recruiting
• Conditions: Cataract; Cataract Bilateral; Cataract Surgery
• Intervention / Treatment: Device: Cataract surgery with Active Sentry; Procedure: Traditional cataract surgery

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: Interventional
• Enrollment (Estimated): 38
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Samir Jabbour, MD,CM,FRCSC; Phone Number: 11550 514-890-8000; Email: Samir.Jabbour.med@ssss.gouv.qc.ca
• Study Contact Backup: Name: Marie-Catherine Tessier, M.Sc.; Phone Number: 11550 514 890-8000; Email: marie-catherine.tessier.chum@ssss.gouv.qc.ca

Participation Criteria

Eligibility Criteria

• 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 22-26mm, refractive error between -5.00D to +5.00D and cylinder ≤ 3.00D, normal K values <47.00D
• Axial eye length cannot vary by more than 0.4 mm between eyes of an individual patient
• 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

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Central corneal thickness at 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

Outcome Measure	Measure Description	Time Frame
Volume of balanced salt solution used during surgery	Volume of balanced salt solution as measured by the Active Sentry Centurion machine	During surgery
Total ultrasound time and total aspiration time	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)	Endothelial cell count measured by specular microscopy	At month 1 and month 3 postoperatively.
Central corneal thickness	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	Measured uring the Pentacam corneal densitometry	Day 1, week 1, month 1 and month 3 postoperatively

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual acuity	Evaluated using a Snellen chart	Day 1, week 1, month 1, and month 3 postoperatively
Low contrast evaluation	Evaluated using the CSV-1000 Contrast Sensitivity chart with glare	Day 1, week 1, month 1, and month 3 postoperatively
Intraocular pressure	Measured using the Goldmann Applanation Tonometer	Day 1, week 1, month 1, and month 3 postoperatively
Cystoid macular edema	Evaluated using the Macular Optical Coherence Tomography (OCT)	1 month postoperatively
Rate of reverse pupillary block	Evaluated using slit lamp examination	1 day, 1 week, 1 month and 3 months postoperatively
Posterior capsular tear	Complication during cataract surgery	During surgery
Posterior capsular rupture	Complication during cataract surgery	During surgery

Collaborators and Investigators

• Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)
• Investigators: Principal Investigator: Samir Jabbour, MD,CM,FRCSC, Centre Hospitalier de l'Universite de Montreal (CHUM)

Publications and helpful links

General Publications

• Zhao Y, Li X, Tao A, Wang J, Lu F. Intraocular pressure and calculated diastolic ocular perfusion pressure during three simulated steps of phacoemulsification in vivo. Invest Ophthalmol Vis Sci. 2009 Jun;50(6):2927-31. doi: 10.1167/iovs.08-2996. Epub 2009 Jan 24.
• Vasavada AR, Praveen MR, Vasavada VA, Vasavada VA, Raj SM, Asnani PK, Garg VS. Impact of high and low aspiration parameters on postoperative outcomes of phacoemulsification: randomized clinical trial. J Cataract Refract Surg. 2010 Apr;36(4):588-93. doi: 10.1016/j.jcrs.2009.11.009.

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2024
• Primary Completion (Estimated): February 1, 2025
• Study Completion (Estimated): March 1, 2025

Study Registration Dates

• First Submitted: September 22, 2024
• First Submitted That Met QC Criteria: September 22, 2024
• First Posted (Actual): September 25, 2024

Study Record Updates

• Last Update Posted (Actual): September 25, 2024
• Last Update Submitted That Met QC Criteria: September 22, 2024
• Last Verified: September 1, 2024

More Information

Terms related to this study

• Keywords: phacoemulsification; cataract surgery; intraocular pressure; cataracts; central corneal thickness; safety profile; Active Sentry; High intra-ocular pressure; physiological IOP
• Additional Relevant MeSH Terms: Eye Diseases; Lens Diseases; Cataract
• Other Study ID 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