title: [Experimental study of the temperature during phacoemulsification].
abstract: Reports on thermal burns during phacoemulsification motivated us to perform an experimental study on the temperature gradient [2,7]. A special measurement technique was developed that enable us to record temperatures in 0.1 s and to document these measurements and interpret them. The experiments were conducted in enucleated pig eyes, as well as in a constructed model of the anterior chamber. Using 500 such measurements, we discuss and demonstrate the influence of the volume of the anterior chamber, the adjustment of the phacoemulsification, the presence of viscoelastic material, the reflection of ultrasonic power on the lens, and insufficient or interrupted irrigation and/or aspiration.
  
  
  RESULTS
  An analysis of the measurements showed that within 8 s extremely high temperatures developed. At the phacosleeve, temperatures of more than 100 degrees C were recorded. Measurements around the phacotip also showed high temperatures resulting in tissue degeneration, especially with simultaneous application of viscoelastic material and/ or the presence of a hard nucleus. When pulse modulation is applied or power reduced, temperatures drop to less than 50%.
  
  
  CONCLUSIONS
  The main factor behind the development of high temperatures is the breakdown of irrigation. The danger of phacoburns increases by application of viscoelastic material, reduced volume of the anterior chamber when there is a hard nucleus and high ultrasonic power with no pulse.
authors.affiliation: Augenklinik, Allgemeines Krankenhaus Barmbek, Hamburg.
authors.forename: H
authors.initials: H
authors.lastname: Wirt
authors.forename: J M
authors.initials: JM
authors.lastname: Heisler
authors.forename: D
authors.initials: D
authors.lastname: von Domarus
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000503:physiopathology; D001833:Body Temperature Regulation / Q000502:physiology*; D002387:Cataract Extraction / Q000295:instrumentation*; D005123:Eye / Q000503:physiopathology; D005126:Eye Burns / Q000503:physiopathology*; D012307:Risk Factors; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013552:Swine; D013821:Thermometers
vernacular_title: Experimentelle Studie zum Temperaturverlauf während der Phakoemulsifikation.