This study will compare two methods of vacuum (peristaltic or venturi) commonly used during the removal of a femtosecond treated cataract. The investigators will observe which method uses less energy, is gentler on the eye, reduces corneal swelling and if the vision recovers faster with one method compared to the other.
This is an open, prospective, randomized study to evaluate efficiency and outcomes of femtosecond laser cataract surgery with phacoemulsification performed with one of two standard vacuum systems. It is estimated that the duration of study participation will be up to 24 months. There will be randomization to 1 of 2 groups. Both eyes of each subject will be enrolled in the study. The first eye will be randomized to either the Venturi or peristaltic-based vacuum pump. The second eye will then receive the other type of vacuum pump for that procedure. Study Phases: Pre-operative Visit Procedure Post-operative Follow up The subject will be seen 1 day, 5-10 days, and 90 days following the procedure. Surgical Procedure * The cataract removal procedure will be performed under sterile technique and according to standard procedures. The femtosecond laser treatment will be followed by phacoemulsification removal of the cataract and implantation of an intraocular lens. * Peri-operatively, subjects will be treated with a regimen of antibiotic, steroid and nonsteroidal anti-inflammatory eye drops per standard of care. * All surgeries will be performed by the same experienced surgeon/principal investigator using the Catalys® SYSTEM femtosecond laser platform and WHITESTAR SIGNATURE® PRO Phacoemulsification System. * Phacoemulsification Settings: * For Venturi pump: 600 mmHg vacuum * For Peristaltic-based pump: 600 mmHg vacuum and aspiration flow of 50 mL/min * Other settings: ultrasound energy application parameters will be the same for the two groups Study Procedures * The study will include routine cataract pre-operative testing with Nidek OPD, Galilei G4, and IOLMaster, and repeated at the post-op visits. An endothelial cell count of the cornea will be performed at the pre-operative visit and at the 90 day follow up visit. * Subjects will be randomized to phacoemulsification settings of Venturi vacuum of 600 mmHg or peristaltic vacuum of 600 mmHg and aspiration flow of 50 mL/min. All other phacoemulsification settings will be identical. The laser settings will be based on the grade of cataract only and will not be altered for this study. * The phacoemulsification time, energy Ellips FX EFX, and average phacoemulsification energy will be recorded. The laser procedure time and total procedure time will be recorded. Complications will be recorded. Additional patient characteristics will also be recorded. * Pre-Operative Visit: * Nidek Refractive Power/Corneal Analyzer OPD-Scan, Galilei G4 Corneal Topography, IOLMaster 700 keratometry (standard of care) * Complete eye examination (standard of care) * Brightness Acuity Test (BAT) (standard of care) * Review and confirm eligibility (research) * Informed Consent for study (research) * Randomization (research) * Endothelial Cell Count (research) * Medical Record Review (research) * Surgical Procedure (Day 0) (standard of care) * Medical Record Review (research) * Adverse Event Assessment (research) * Post-operative Visit 1 (Day 1): * Eye exam to include uncorrected and pinhole visual acuity, Intraocular pressure (IOP) and slit-lamp exam (standard of care) * Galilei G4 Corneal Topography, IOLMaster 700 keratometry (standard of care) * Medical Record Review (research) * Adverse Event Assessment (research) * Post-operative Visit 2 (Day 5-10): * Eye exam to include uncorrected and best corrected visual acuity, Pinhole visual acuity, IOP, and slit-lamp exam (standard of care) * Nidek Refractive Power/Corneal Analyzer OPD-Scan, Galilei G4 Corneal Topography, IOLMaster 700 keratometry (standard of care) * Medical Record Review (research) * Adverse Event Assessment (research) * Post-operative Visit 3 (Day 60-90 days): * Eye exam to include uncorrected and best corrected visual acuity, Pinhole visual acuity, IOP, and slit-lamp exam (research) * Nidek Refractive Power/Corneal Analyzer OPD-Scan, Galilei G4 Corneal Topography, IOLMaster 700 keratometry (research) * Endothelial Cell Count (research) * Medical Record Review (research) * Adverse Event Assessment (research) * Unscheduled Visit: * A medical record review and an adverse event assessment will be performed at any unscheduled visit. * Additional evaluations will be completed at the discretion of the Principal Investigator based on the subject's presenting complaint. Statistical Analysis Sample Size and Power: · The study aims to enroll 250 study subjects for a total of 500 eyes with bilateral grade 1-3 nuclear sclerotic cataracts who will be undergoing planned femtosecond laser cataract surgery. Statistical Methods: · The statistical analysis plan will include use of descriptive statistics and statistical tests including unpaired t-tests.
Study Type
OBSERVATIONAL
Enrollment
111
The venturi pump makes use of the venturi effect to create a vacuum. The venturi effect creates a vacuum by the flow of a fluid, typically air, over an opening. In many phacoemulsification machines, this requires nitrogen tanks or a self-contained air compressor. The vacuum level is created within a rigid drainage cassette, to which the phaco aspiration tubing is connected. Since there is no milking of the aspiration line, the phaco tubing can be made rigid with low compliance.
The peristaltic pump uses rollers to compress the phacoemulsification outflow tubing in a peristaltic manner, thereby creating flow and vacuum. The compression of the rollers on the tubing with the rotation of the pump physically moves fluid and creates a continuous "milking" action on the fluid column, The phaco machine can directly control this flow level, hence the term flow based, however, the preset vacuum level is only achieved once there is occlusion of the outflow line, typically at the phaco needle tip with cataract material.
Mercy Clinic Eye specialists
Springfield, Missouri, United States
Phacoemulsification energy required during femtosecond laser cataract surgery procedure
Phaco EFX (the effective phaco time with a specific coefficient for the transversal movement of the phaco tip- expressed in seconds.)
Time frame: Intraoperative Visit
Duration of ultrasound time required during femtosecond laser cataract surgery procedure
Total ultrasound time - measured in seconds
Time frame: Intraoperative Visit
Phacoemulsification power required during femtosecond laser cataract surgery procedure
Average power - measured in percentage
Time frame: Intraoperative Visit
Duration of microscope time required during femtosecond laser cataract surgery procedure
Microscope time - measured in seconds intraoperatively
Time frame: Intraoperative Visit
Duration of laser time required during femtosecond laser cataract surgery procedure
Laser time - measured in seconds intraoperatively
Time frame: Intraoperative Visit
Uncorrected visual acuity among subjects who underwent femtosecond laser cataract surgery procedure
1\) Uncorrected Visual Acuity using the Snellen Eye Chart
Time frame: This test will be done Pre-operatively and at Post op day 1, Post op day 5-10, and Post op day 60-90
Best Corrected Visual Acuity among subjects who underwent femtosecond laser cataract surgery procedure
Best Corrected Visual Acuity using the Snellen Eye Chart
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Time frame: This test will be done Pre-operatively and at Post op day 1, Post op day 5-10, and Post op day 60-90
Pinhole Visual Acuity among subjects who underwent femtosecond laser cataract surgery procedure
Pinhole visual acuity using pinhole technique and the Snellen eye chart
Time frame: This test will be done Pre-operatively and at Post op day 1, Post op day 5-10, and Post op day 60-90
Presence of corneal edema as assessed by intra-ocular pressure
Measured in mmHg using an applanation tonometer
Time frame: This test will be done Pre-operatively and at Post op day 1, Post op day 5-10, and Post op day 60-90
Presence of corneal edema as assessed by slit lamp examination
The examiner will use a slit lamp microscope to evaluate the eye structures and intra-ocular pressure
Time frame: This test will be done Pre-operatively and at Post op day 1, Post op day 5-10, and Post op day 60-90
Measure of the corneal endothelium
Endothelial Cell Count will be evaluated by Konan Specular Microscopy
Time frame: This test will be done Pre-operatively and Post op 60-90 day visit
Central corneal thickness as measured by IOLMaster Biometry
IOL Master Biometry directly measures the corneal thickness by OCT
Time frame: This test will be done Pre-operatively and at Post op day 1, Post op day 5-10, and Post op day 60-90
Central corneal thickness as measured by Galilei G4 Biometry
Galilei G4 measures central corneal thickness
Time frame: This test will be done Pre-operatively and at Post op day 1, Post op day 5-10, and Post op day 60-90