title: Endothelial protection: avoiding air bubble formation at the phacoemulsification tip.
abstract: OBJECTIVE
  To investigate the conditions under which bubbles form during phacoemulsification.
  
  
  METHODS
  Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
  
  
  METHODS
  In the first part of the study, the partial pressure of oxygen (pO(2)) was used as a surrogate measure for the partial pressure of air. Irrigation solutions packaged in glass and plastic containers were studied. A directly vented glass bottle was also tested. The pO(2) of the various irrigation solutions was measured as the containers were emptied. In the second part, phacoemulsification procedures were performed in rabbit eyes with different power settings and different irrigation solutions. Intracameral bubble formation during the procedure was recorded. Following the phacoemulsification procedures, the corneas were stained for F-actin and examined for endothelial injury.
  
  
  RESULTS
  The initial pO(2) in irrigation solutions packaged in glass bottles was about half that at atmospheric levels; in solutions packaged in plastic, it was at atmospheric levels. As irrigation solutions were drained from the container, the pO(2) of the solution tended to rise toward atmospheric levels. The rate of pO(2) increase was markedly reduced by using a directly vented glass bottle. In the phacoemulsification procedures, bubble formation was most likely to occur with higher pO(2) and higher power settings. Observation of bubbles by the surgeon was highly correlated with endothelial damage.
  
  
  CONCLUSIONS
  Keeping the pO(2) low reduced the risk of endothelial damage, especially at higher phacoemulsification powers. The packaging of irrigation solutions was the most important factor in controlling the initial pO(2) of the solution. The pO(2) can be minimized throughout a phacoemulsification procedure by using a directly vented glass bottle.
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University, Seoul, South Korea. eungkkim@yumc.yonsei.ac.kr
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Cristol
authors.forename: Shin J
authors.initials: SJ
authors.lastname: Kang
authors.forename: Henry F
authors.initials: HF
authors.lastname: Edelhauser
authors.forename: Dong-Soo
authors.initials: DS
authors.lastname: Yeon
authors.forename: Jae Bum
authors.initials: JB
authors.lastname: Lee
mesh_terms: D000199:Actins / Q000378:metabolism; D000388:Air; D000818:Animals; D019610:Cytoprotection; D004349:Drug Packaging; D004728:Endothelium, Corneal / Q000293:injuries* / Q000378:metabolism; D005131:Eye Injuries / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D007431:Intraoperative Complications / Q000378:metabolism / Q000517:prevention & control*; D009883:Ophthalmic Solutions; D010100:Oxygen / Q000378:metabolism; D010313:Partial Pressure; D018918:Phacoemulsification / Q000009:adverse effects / Q000379:methods*; D011817:Rabbits; D007507:Therapeutic Irrigation
chemical_list: D000199:Actins; D009883:Ophthalmic Solutions; D010100:Oxygen