Residual cleaner after normal cleaning of laser in situ keratomileusis instruments.

Purpose: To determine whether residual cleaner could be detected in the rinse solution of surgical instruments after a standard cleaning protocol.

Setting: Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

Methods: The wavelength for maximum absorbance of 5 cleaners (Endozime) [The Ruhof Corp.], Enzol/Cidezyme [Advanced Sterilization Products], and Klenzyme [Steris Co.] enzymatic detergents; Palmolive Ultra dishwashing liquid [Colgate-Palmolive Co.]; and Universal concentrated surgical instrument cleaner and lubricant [B. Graczyk, Inc.]) was determined. Identically designed stainless-steel and titanium instruments were cleaned using a standardized protocol. Water temperatures of 25 degrees C (room temperature) or 40 degrees C (warm temperature) were used to rinse the instruments. The amount of residual cleaner in each rinse solution and remaining on each instrument at the completion of the cleaning procedure as a percentage of the total cleaner was determined.

Results: Residues of all cleaners were detected using a standard protocol involving rinse solutions at 25 degrees C. Increasing the temperature of the rinse solutions significantly reduced the cleaner residues (P<.05, Friedman repeated-measures analysis of variance on ranks test and Student-Newman-Keuls test) regardless of the instrument material. No significant difference was detected in the residual cleaners on stainless-steel and titanium instruments.

Conclusions: Lower levels of cleaner residue were found on surgical instruments after a standard cleaning protocol using warm rinse water. Because cleaner residue has been reported to cause inflammation (eg, diffuse lamellar keratitis) after laser in situ keratomileusis (LASIK), it is advisable to use cleaners and cleaning protocols that result in acceptable cleaning without detectable levels of cleaner residue to avoid potentially harmful effects to the cornea after LASIK.