Abstract
Purpose: :
To evaluate new vitreous cutter technology that has ultra-high speed cutting capability (up to 5000 cuts per minute), and duty cycle control (port biased open versus closed).
Methods: :
Comparison between traditional pneumatic guillotine vitrectomy cutters that operate with a pneumatic drive pulse acting upon an elastic diaphragm that pushes the cutter against a return spring, electrically operated cutters that either use a rotation electric motor or solenoid drive, and the new guillotine cutters that are driven open and closed with a pneumatic drive pulse acting upon a diaphragm. Evaluation of maximum and minimum flow rates at varying cutter speeds was performed.
Results: :
As cut rate was increased, the volume of each individual vitreous "bite" or flow was reduced. When holding a constant flow rate of 8 cc per minute, at 1500 cuts per minute (cpm) the discrete aspirated volume was 5.3 µl/cut (8/1500). At 5000 cpm the discrete aspirated volume was significantly reduced to 1.6 µl /cut (8/5000). Increased flow rates could be obtained by increasing vacuum or varying the duty cycle. Higher flow rates could be achieved with a biased open duty cycle while port based flow limiting could be achieved with a biased closed duty cycle.
Conclusions: :
The new vitreous cutter technology offers surgeons better safety and efficiency by increasing cut speed and offering control of duty cycle. These factors allow precise control over vitreous flow levels during vitrectomy surgery.
Keywords: vitreoretinal surgery • retina