title: Alteration of free radical development by ophthalmic viscosurgical devices in phacoemulsification.
abstract: OBJECTIVE
  To determine the effect of ophthalmic viscosurgical devices (OVDs) and irrigation/aspiration (I/A) settings on free radical development during phacoemulsification.
  
  
  METHODS
  Department of Ophthalmology, Nippon Medical School, Tokyo, Japan.
  
  
  METHODS
  Free radicals were detected by the electron spin resonance (ESR) spin-trap method. After a spin-trapping agent, 5,5-dimethyl-1-pyrroline N-oxide 1%, was mixed with the irrigating solution, phacoemulsification simulation was performed in an eye model at 100% ultrasound power levels for 10, 20, and 30 seconds. A high I/A setting (35 mL/min with 250 mm Hg vacuum) and a low I/A setting (15 mL/min with 60 mm Hg vacuum) were used in combination with no OVD, sodium hyaluronate 1% (Healon), sodium hyaluronate 2.3% (Healon5), sodium hyaluronate 3%-chondroitin sulfate 4% (Viscoat), or sodium hyaluronate 1% (Opegan). Immediately after phacoemulsification, the solution in the anterior chamber was collected and signals from the spin adduct were measured using an ESR spectrometer.
  
  
  RESULTS
  With the low setting, all OVDs significantly suppressed the signals for up to 20 seconds. At 30 seconds, the signals were still significantly smaller in all OVD groups, except Healon, than those in the no-OVD. With the high setting, the effect was not significant in the Healon and Opegan groups at 10 seconds; by 20 seconds and after, only Viscoat showed significant suppression.
  
  
  CONCLUSIONS
  Free radical development in phacoemulsification can be altered by OVD properties and I/A settings. To reduce oxidative stress to the corneal endothelium, attention should be paid to the retention of OVDs in the anterior chamber during phacoemulsification.
authors.affiliation: Departments of Ophthalmology, Nippon Medical School, Tokyo, Japan. tash@nms.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Hisaharu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shiwa
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Sakamoto
mesh_terms: D000818:Animals; D002807:Chondroitin / Q000378:metabolism*; D002809:Chondroitin Sulfates; D003497:Cyclic N-Oxides / Q000378:metabolism; D004322:Drainage; D004338:Drug Combinations; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000378:metabolism*; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism*; D008953:Models, Anatomic; D009883:Ophthalmic Solutions; D018918:Phacoemulsification; D013113:Spin Labels; D007507:Therapeutic Irrigation
chemical_list: D003497:Cyclic N-Oxides; D004338:Drug Combinations; D005609:Free Radicals; D009883:Ophthalmic Solutions; D013113:Spin Labels; C501944:chondroitin sulfate, sodium hyaluronate drug combination; C055956:5,5-dimethyl-5-hydroperoxy-1-pyrrolidinyloxy; D006820:Hyaluronic Acid; D002807:Chondroitin; D002809:Chondroitin Sulfates