Abstract
Abstract: :
Purpose: To determine whether the plume produced during excimer laser refractive surgery contains solid components, and if so, to characterize the nature of those components. Methods: Filter elements were removed from the smoke evacuator of a VISX S3 excimer laser (filter pore size ∼0.3 microns) and from a Mastel Clean Room (Mastel Precision Instruments, Rapid City, SD, filter pore size ∼0.2 microns) used with a LADARVISION excimer laser. Both laser systems were used in routine LASIK refractive procedures, and the filters captured the laser-induced plumes from multiple patient procedures. The filters were stored at -70 deg C until use, and then processed for scanning electron microscopy either with or without prior fixation in 1% glutaraldehyde. Both sides of the filters were examined. Results: Both the VISX "Final Air" filter and the Mastel "Clean Room" filter captured solid particles that were not observed in control filters that simply had operating room air passed through them. In the VISX system, air flows through the filter unit parallel to the filter matrix. These filters appeared to catch occasional particles which, based on the SEM analysis, were 0.3 to 3.0 microns in size. In the Mastel Clean Room unit, air flows orthogonally through the filter, and the filter matrix was heavily layered with captured debris so that individual particles were not distinguished. Conclusions: In contrast to previous studies that reported mainly small molecules (<100 MW) in the excimer laser plume, the appearance of the smoke evacuator filters in this study suggests much larger molecules in the debris ejected from the cornea. The nature of this debris will be characterized using HPLC and mass spectrometry. Whether the laser plume debris poses a risk to the LASIK surgical team remains to be determined.
Keywords: 548 refractive surgery: LASIK • 472 microscopy: electron microscopy • 454 laser