Quantification of hydroxyl radical produced during phacoemulsification.
OBJECTIVE
To quantitate hydroxyl radicals produced during phacoemulsification with various irrigating solutions and conditions used in cataract surgery.


METHODS
Chemistry and Biochemistry Department, Utah State University, Logan, Utah, USA.


METHODS
All experiments were performed using an Infiniti Vision System phacoemulsifier with irrigation and aspiration. Hydroxyl radicals were quantitated using electron spin resonance spectroscopy and a spectrophotometric assay for malondialdehyde, which is formed by the oxidation of deoxyribose by the hydroxyl radical.


RESULTS
Hydroxyl radical production increased during longitudinal-stroking phacoemulsification as power levels were increased in a nonlinear, nonexponential fashion. The detection of hydroxyl radical was reduced in irrigating solutions containing organic molecules (eg, citrate, acetate, glutathione, dextrose) and further reduced in Navstel, an irrigating solution containing a viscosity-modifying agent, hydroxypropyl methylcellulose.


CONCLUSIONS
Hydroxyl radicals produced in settings representative of those used in phacoemulsification cataract surgery were quantitated using the deoxyribose method. Hydroxyl radical production was dependent on the level of ultrasound power applied and the irrigating solution used. Oxidative stress on the eye during phacoemulsification may be minimized by using irrigating solutions that contain organic molecules, including the viscosity-modifying agent hydroxypropyl methylcellulose, that can compete for reaction with hydroxyl radicals.
Gardner
Jonathan M
JM
Chemistry and Biochemistry Department, Utah State University, Logan, 84322-0300, USA.
Aust
Steven D
SD
D000085:Acetates; D001639:Bicarbonates; D004322:Drainage / Q000379:methods; D004338:Drug Combinations; D004578:Electron Spin Resonance Spectroscopy; D005978:Glutathione; D006801:Humans; D017665:Hydroxyl Radical / Q000032:analysis*; D008315:Malondialdehyde / Q000032:analysis; D008903:Minerals; D018918:Phacoemulsification; D012965:Sodium Chloride; D007507:Therapeutic Irrigation; D014867:Water
D000085:Acetates; C030660:BSS solution; D001639:Bicarbonates; D004338:Drug Combinations; D008903:Minerals; C013003:glutathione-bicarbonate-Ringer solution; D014867:Water; D017665:Hydroxyl Radical; D012965:Sodium Chloride; D008315:Malondialdehyde; D005978:Glutathione