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

NCT06611670 — Not applicable, Completed, 31 participants, Centre hospitalier de l'Université de Montréal (CHUM)

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RegistryNCT06611670, acronym ACTIVESENTRY
StatusCompleted
PhaseNot applicable
Study typeInterventional; randomized, parallel, masking: triple, treatment
Enrollment31 (Actual)
SponsorCentre hospitalier de l'Université de Montréal (CHUM) (Other)
ConditionsCataract, Cataract Surgery, Cataract Bilateral
InterventionsCataract surgery with Active Sentry, Traditional cataract surgery (Device, procedure)
Datesstart 2025-01-01, primary completion 2026-03-31, completion 2026-03-31, first posted 2024-09-25, last updated 2026-08-14
Locations1 site in Canada

Related Papers Related Patents Related Grants Related Experts
All trials for Cataract All trials for Cataract Surgery All trials of Cataract surgery with Active Sentry All trials of Traditional cataract surgery

-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.

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+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.

+Arms and interventions

ArmTypeInterventionsDescription
Cataract surgery with Active SentryExperimentalDevice: Cataract surgery with Active SentryCataract surgery with low IOP values (32mmHg)
High IOPActive comparatorProcedure: Traditional cataract surgeryCataract surgery with high IOP (60mmHg) which is the average pressure at which cataract surgery is being performed currently
  • Cataract surgery with Active Sentry (Device): Surgical instrument that detects changes in intraocular pressure and allows rapid feedback to stabilize pressure during cataract surgery.
  • Traditional cataract surgery (Procedure): Cataract surgery performed with high intraocular pressures

+Outcome measures

Primary outcomes

  • Central corneal thickness at 1 day postoperatively [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).

Secondary outcomes

  • Volume of balanced salt solution used during surgery [During surgery]: Volume of balanced salt solution as measured by the Active Sentry Centurion machine
  • Total ultrasound time and total aspiration time [During surgery]: Total 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 thickness [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).
  • Corneal clarity [Day 1, week 1, month 1 and month 3 postoperatively]: Measured uring the Pentacam corneal densitometry

Other outcomes

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

+Eligibility

Sex: All, ages: 18 Years to any, accepts healthy volunteers

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.

+Locations (1)

FacilityCityCountryStatus
Centre Hospitalier de l'Université de MontréalMontreal, QuebecCanada

+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. PMID 19168897
  • 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. PMID 20362850

+Investigators

+Funding

NIH grants: 2025