Measuring rectilinear flow within the anterior chamber in phacoemulsification procedures

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Fluid Dynamics

Background:

• Phacoemulsification is a common cataract surgery technique.
• Understanding fluid dynamics during phacoemulsification is crucial for minimizing ocular tissue damage.
• Different phacoemulsification modes may produce varying degrees of fluidic stress.

Purpose of the Study:

• To quantify and visualize fluid flow patterns in an anterior chamber model during phacoemulsification.
• To compare the fluid dynamics generated by different phacoemulsification power modes.

Main Methods:

• Utilized a silicone anterior chamber model with balanced salt solution.
• Employed laser Doppler vibrometry to measure vibration velocity and displacement.
• Used Schlieren photography to visualize fluid flow dynamics.
• Tested four ultrasound (US) delivery modes: WhiteStar DB, WhiteStar CF, continuous, and short-pulse (6 pps) at 20% and 50% power.

Main Results:

• Continuous mode exhibited the highest peak vibration velocity and displacement, followed by short-pulse, WhiteStar DB, and WhiteStar CF.
• At 50% power, continuous mode generated a peak velocity of 12.8 x 10(-3) m/s, while WhiteStar CF produced 6.37 x 10(-3) m/s.
• Schlieren photography revealed greater wave speed, intensity, and turbulence in continuous mode compared to WhiteStar modes.

Conclusions:

• WhiteStar delivery modes resulted in lower peak vibration velocity and displacement amplitude than continuous or short-pulse modes.
• A reduction in rectilinear flow and turbulence was observed with WhiteStar modes.
• These findings suggest potential clinical benefits for corneal endothelium protection during phacoemulsification.