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After completing conventional or wavefront custom Lasik, All-Laser Lasik, PRK, LASEK, Epi-Lasik, laser eye surgery, patients often exclaim, "I can see!", shortly followed by, "What was that smell?" The process of laser eye surgery can cause the disconcerting smell of burning flesh. The excimer laser is a "cold" laser and does not remove tissue with heat. The concentrated light frequency disrupts the molecular bonds that hold together the corneal cells. Without these bonds the cells escape in a the form of a mushroom cloud that looks similar to an atomic bomb. As these cells rapidly move away from the cornea they strike each other causing a minor heat buildup from friction. That buildup can raise the temperature of the cornea to about 110°F (43°C), or around 11°F (6°C) above normal body temperature and very close to the water temperature of a nice warm hot tub. A second-degree burn threshold is skin temperature raised to 175°F (79°C). A third-degree burn threshold is skin temperature raised to 200°F (93°C). The smell, which is remarkably like the smell of burning flesh, is from the chemical reaction of the laser on the cornea, not from heat. Some surgeons use a special vacuum device surrounding the eye that removes these cells throughout the procedure so the source of the unpleasant smell is removed. Even if it is only a chemical reaction via laser and not heat, nobody wants to experience what smells like their eye burning. If you are ready to choose a doctor to be evaluated for conventional or custom wavefront Lasik, All-Laser Lasik, PRK, LASEK, Epi-Lasik, NearVision CK, RLE, or any refractive surgery procedure, we highly recommend you consider a doctor who has been evaluated and certified by the USAEyes nonprofit organization. Locate a USAEyes Evaluated & Certified Lasik Laser Eye Surgery Doctor. If this article did not fully answer your questions, use our free Ask Lasik Expert patient forum.
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Current Lasik Medical Journal News...
Histological changes and unscheduled DNA synthesis in the rabbit cornea following 213-nm, 193-nm, and 266-nm irradiation.
Histological changes and unscheduled DNA synthesis in the rabbit cornea following 213-nm, 193-nm, and 266-nm irradiation. J Refract Surg. 2007 May;23(5):477-81 Authors: Van Saarloos PP, Rodger J PURPOSE: To examine the acute outcome of corneal irradiation in adult rabbits for 193-, 213-, and 266-nm laser wavelengths. METHODS: Animals were randomly allocated to one of three groups and were treated with 213-nm quintupled Nd:YAG laser, a 193-nm excimer laser, or a 266-nm quadrupled Nd:YAG laser (n = 6 per group, two exposure durations). Thermal damage was assessed histologically and the extent of DNA damage estimated by measuring unscheduled DNA synthesis in corneal epithelial and stromal cells using 3H thymidine autoradiography. RESULTS: For the 193- and 213-nm groups, irradiation did not induce thermal damage. Moreover, cells displaying unscheduled DNA synthesis represented < 4% of the total cell numbers with no difference between groups (P > .05). By contrast, the 266-nm laser led to stromal melting and vacuolation; unscheduled DNA synthesis levels were elevated over the other groups (P < .05). CONCLUSIONS: Corneal laser ablation with the 213-nm Nd:YAG laser resulted in similarly low levels of thermal and DNA damage to those produced using the clinically accepted 193-nm excimer laser. PMID: 17523509 [PubMed - indexed for MEDLINE] Last updated Tuesday, May 06, 2008 |
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