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Plume evacuator may lessen health risk for LASIK and PRK
A high-filtration mask and high turnover-time ventilation system may also reduce the risk of surgical smoke. Further study is needed.
SAN FRANCISCO – It is unclear whether inhaling surgical smoke when performing LASIK and photorefractive keratectomy procedures poses a health threat. But some physicians feel it may be better to be safe than sorry.
“We cannot say at this time that there is a health hazard, but there is a theoretical health hazard,” said Howard V. Gimbel, MD, FRCSC, medical director of the Gimbel Eye Centre in Calgary, Canada, and professor and chair of the department of ophthalmology of Loma Linda University.
“There are also some anecdotal reports of people who think they may have developed a respiratory problem from the plume. Anything you inhale can be an irritant. Some people are even bothered by perfume. If we can smell something, it means it is getting to our nostrils and into our lungs. However, nothing has been proven yet,” he said.
“I believe that LASIK and PRK surgeons who use the excimer laser need to pay more attention to the plume particles. The size of these particles and the size distribution are important,” Dr. Gimbel said at the American Society of Cataract and Refractive Surgery meeting here.
Average particulate size
There is small study regarding the composition of the cloud that rises off the cornea during the ablative process, said Matthew S. Niemeyer, MD, a research coordinator at Loma Linda University in California. In the study a filter was used to remove the plume and then the particulate size was looked at with electron microscopy. The investigators determined that the average size of particulate matter was about 0.22 µm, he said. A comparable study was conducted by Drs. Niemeyer and Gimbel.
“We found our graph to be very similar, with an average size of approximately 0.22 µm,” Dr. Niemeyer said. Particle-size distribution also matched closely in both studies.
Dr. Niemeyer noted that a 0.22-µm particle “can travel all the way down to the alveoli in the lung, where it has fairly direct access to the blood through the small capillaries.” At that level, a small particle can act as an irritant, “which is probably the most common activity,” he said. “But it could also potentially cause an autoimmune response.”
Plume evacuator
To lessen the potential hazard of surgical smoke, Dr. Gimbel uses a plume evacuator called the Laser Clean Room (Mastel Precision).
“This device aspirates the plume and filters it so it does not come back into the atmosphere. [As a result,] neither the patient nor personnel in the operating room smell the smoke because most of it ends up being evacuated,” he said.
The Laser Clean Room fits right on the eye.
“It takes a little skill development to properly use. Some eye-tracking systems might not be compatible either,” Dr. Gimbel said.
He said he appreciates the fact that the Laser Clean Room has a fiber-optic side illumination for enhanced visualization of the pupil and a very dark iris.
“This illumination helps to ensure centration,” he said. The device also has a flap-hinge protector.
Dr. Gimbel has been using the Laser Clean Room for a number of years at both his Loma Linda and Calgary practices.
“We feel that it is well-designed,” he said. “There are other manufacturers that make filtration systems or only evacuation systems. But we have to make sure that any filters or systems available to remove the plume are actually effective. Different filters are made for different particulate sizes.”
Health survey
Drs. Gimbel and Niemeyer are conducting a health survey at about 50 major ophthalmic surgical sites.
“This will allow us to actually state, as compared to the control group, whether there is a significant increase in health problems,” Dr. Niemeyer said.
Apart from a plume evacuator, a high-filtration mask (TB mask) is advised.
“These masks filter down to around 0.1 µm. A regular mask will be fairly ineffective in filtering particles of that size,” he said.
Dr. Niemeyer is less concerned about patients using a mask because they have a one-time exposure, he said, and the particles from the plume originate from the patient’s own cornea.
However, he added, particles are so small that they do not settle, so a heating and cooling ventilation system with a high-turnover time is helpful.
“It is nice for the patient to not have that smell. It is also nice for the surgeon and staff,” Dr. Gimbel said.
There is also the potential for viral aerosolization, whereby viruses can be ejected from the cornea and into the room for the spreading of diseases. Studies have found a few viruses, including oral polio virus, that do survive laser treatments.
Drs. Gimbel and Niemeyer have communicated with aerosol experts and professionals who study various atmospheric pollutants.
“We believe surgical smoke is worth scientific study, and that is what we are doing,” Dr. Gimbel said.
A film on excimer laser plume, which was produced by the two surgeons, was shown at the ASCRS meeting.
For Your Information:
- Howard V. Gimbel, MD, FRCSC, can be reached at the Gimbel Eye Center, Market Mall Professional Center, Room 450, 4935 40th Ave. NW, Calgary, Alberta, T3A 2N1; (403) 286-3022; fax: (403) 286-2943; e-mail: hvgimbel@gimbel.com. Dr. Gimbel has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
- Matthew S. Niemeyer, MD, can be reached at 11370 Anderson St., Suite 1800, Loma Linda, CA 92354; (909) 558-2000; fax: (909) 558-2180; e-mail: mniemeyer@ahs.llumc.edu. Dr. Niemeyer has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.
- Mastel Precision, maker of the Laser Clean Room, can be reached at 2843 Samco Rd., Suite A, Rapid City, SD 57702; (800) 657-8057; (605) 343-3631; e-mail: mastel@mastel.com.