title: Thermal effect of microburst and hyperpulse settings during sleeveless bimanual phacoemulsification with advanced power modulations.
abstract: OBJECTIVE
  To assess wound temperature during bimanual sleeveless phacoemulsification using customizable power modulations such as hyperpulse and microburst technology.
  
  
  METHODS
  In vitro laboratory.
  
  
  METHODS
  The Millennium Microsurgical System (Bausch & Lomb) with custom control software (CCS) was used to perform phacoemulsification in 5 porcine eyes with MicroFlow needles (Bausch & Lomb) and with power varied from 20% to 80% in 10% increments. Pulse modes were set for fixed microburst (4 ms on, 4 ms off; and 6 ms on, 12 or 24 ms off) and for hyperpulse (30% duty cycle with 8 or 75 pulses per second [pps]), with and without aspiration-line occlusion. Wound temperatures were measured 3 times per second.
  
  
  RESULTS
  Using 80% total power, the wound temperature during 3 minutes of occlusion did not exceed 39.0 degrees C. The maximum temperature with fixed microbursts of 4 ms on, 4 ms off was 29.0 degrees C without occlusion and 37.8 degrees C with occlusion (duration 3 minutes). At 6 ms on, 12 ms off, the maximum temperatures were 28.1 degrees C and 38.7 degrees C, respectively. At 6 ms on, 24 ms off, peak temperatures were 24 degrees C and 23.6 degrees C, respectively. The hyperpulse mode of 30% duty cycle and 8 pps produced maximum temperatures of 25.5 degrees C nonoccluded and 33.4 degrees C occluded. With 30% duty cycle, 75 pps, temperatures were 28 degrees C and 38.0 degrees C, respectively. For all power below 80%, temperatures were lower.
  
  
  CONCLUSIONS
  Customizable power modulation with microburst and hyperpulse technology further reduced wound temperatures during bimanual sleeveless phacoemulsification. This enhances the safety and effectiveness of phacoemulsification through a sleeveless needle and a small stab incision.
authors.affiliation: Department of Ophthalmology, University of Toronto, Toronto, Canada. rbragamele@rogers.com
authors.forename: Rosa
authors.initials: R
authors.lastname: Braga-Mele
mesh_terms: D000818:Animals; D000869:Anterior Eye Segment / Q000293:injuries* / Q000503:physiopathology; D001831:Body Temperature; D005126:Eye Burns / Q000503:physiopathology*; D006358:Hot Temperature; D018918:Phacoemulsification / Q000379:methods*; D013552:Swine; D013997:Time Factors