Venturi and Peristaltic Based Phacoemulsification in Femtosecond Laser Cataract Surgery
Condition: Cataract Senile
MeSH terms: Cataract
Study type: Observational

Summary: 
      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.
    

Detailed description: 
      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.
    

Intervention name(s): Venturi pump; Peristaltic vacuum pump
Intervention type(s): Device; Device
Intervention description(s): 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.
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        -  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.

          -  The study will include adults undergoing femtosecond laser cataract surgery with grade
             1-3 nuclear sclerotic cataracts.