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เทคโนโลยีในการทำเลสิค History Of Laser Surgery Since the 1940s, different kinds of refractive surgery have evolved as ways to permanently correct refractive errors. Today there are several types of refractive surgery, some widely used for decades, some still experimental. The most important of the earlier refractive surgeries are radial keratotomy (RK) and photorefractive keratectomy (PRK). What Is Radial Keratotomy (RK) Radial Keratotomy (RK) corrects myopia by flattening the central cornea using a series of peripheral cuts (incisions) radiating from the central cornea. A hand-held knife with a retractable diamond cutting tip is used to perform the operation. The optical zone (the central part of the cornea that's responsible for our most critical vision) is marked off with a circular ring. Corneal thickness is measured and the diamond cutting tip is extended to the appropriate length. Incisions are made from the edge of the optical zone out to the edge of the cornea. By doing so, the central optical zone is not touched. RK can treat only low degrees of myopia and astigmatism, but LASIK can also treat hyperopia and higher degrees of myopia and astigmatism. What Is Photorefractive Keratectomy (PRK) Photorefractive Keratectomy (PRK) is a surgical procedure that uses an extremely precise laser to remove corneal tissue for the purpose of correcting refractive error. PRK takes place on the surface of the cornea. Since the central corneal epithelium (the outer layer of corneal cells) needs to be removed for PRK, and there are nerve fibers that run through it, there may be discomfort initially. This discomfort is equivalent to a badly scratched eye or a corneal abrasion and it can cause pain, irritation, watering of the eye, blurry vision, or the sensation of a particle in the eye. A bandage contact lens helps to reduce the irritation and encourage healing of the tissue. Following PRK, vision is blurry the first few days, but it generally improves once the corneal epithelium has healed and the bandage lens is removed. By one week, vision should be reasonably good and is often stabilized by six months. What Does PRK Have To Do With Lasik? LASIK evolved from PRK and both surgeries use lasers in a similar manner. LASIK provides the same visual-correction benefits, but generally with fewer and less severe side effects than PRK. LASIK uses an excimer laser to ablate part of the corneal stroma. Since LASIK does not disturb the sensitive top layer of the cornea there is less discomfort with this procedure and there is faster recovery. What Is An Excimer Laser? An excimer laser is a precise computerized instrument that uses invisible ultra-violet light to ablate the cornea during refractive surgery. This cool light laser produces virtually no damage to the surrounding tissue, increasing its safety. Each pulse of the laser removes only a minute amount of corneal tissue about 1/500th of the thickness of a human hair. First- and second-generation excimer lasers use a broad beam (about 6 mm in diameter) with an aperture that controls the amount of the beam that is exposed to the eye during any single pulse. Manufacturers have refined this technology by splitting the single broad beam into several smaller beams that are rotated around the treatment area (similar to how a showerhead splits the main water stream into smaller streams). Flying Spot Newer generation excimer lasers, such as Bausch & Lomb's Technolas® 217A, utilize an innovative technology called a "flying spot laser." A narrow beam (about 2 mm wide) contacts the eye at lightning speed in a pattern that allows the debris to clear in one place before contacting that area again. The laser beam covers a broad surface area, but does not penetrate as deeply as in RK procedures. Unlike the broad beam, the full width of the flying spot beam is exposed to the cornea during every pulse. This technology produces a smoother corneal shape and helps increase the accuracy and efficacy of the surgery. The newest generation excimer laser, the Technolas® 217z Zyoptix System for Personalized Laser Vision Correction, combines both a 2mm and a 1mm beam Advancements To Laser Surgery Since 1991 Bausch & Lomb (then Chiron Vision) has been the leader in refractive technologies. B&L's initial success in RK led to an education program that effectively trained surgeons entering the refractive market, and validated the efficacy of the procedure. In 1993, B&L launched the Keracor 116 excimer laser. Although excimer lasers were initially introduced for PRK, key opinion leaders began to look at the minimal wound healing effects of LASIK with great interest. The following year, B&L established a LASIK Advisory Board comprised of 14 of the world's most insightful leaders in the field of refractive surgery; these "pioneers" established a standardized LASIK surgical technique, and developed a related training program. Bausch & Lomb's C-LASIK education program includes a network of over 70 teaching physicians and covers new product innovations such as the Hansatome® microkeratome, the Technolas® 217A excimer laser and Technolas® 217z Zyoptix wavefront-guided laser for correction of myopia. The program serves both to validate and proliferate LASIK as a safe and effective method of vision correction. In 2003, Bausch & Lomb introduced Zyoptix a new personalized laser vision correction system unique to each eye for sharp, clear, and accurate vision. ว่างๆจะแวะมาแปลให้นะคะ เอามาจากเว็บไซด์ของ Bausch&Lomb ค่ะ
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ได้คำตอบมาว่า เป็นเครื่องตัวเดียวกัน ใช้เลเซอร์แบบ flying spot เหมือนกัน เพียงแต่มันมีความสะดวกในการใช้ต่างกัน ก็คือว่าจะเป็น generation ไหน ก็ไม่มีผลกับตัวคนไข้ แต่มันเป็นความสะดวกสบายของหมอผู้ set up เครื่องเท่านั้นเองว่าจะใช้ได้ง่ายหรือยาก ก็คงจะคล้ายๆกับคอมพิวเตอร์ใช้ดูหนัง software ที่ใช้อาจจะต่างกัน มีปุ่มต่างๆกัน แต่ผลออกมาก็เป็นหนังให้เราดูเหมือนๆกัน อะไรทำนองนี้แหละค่ะ ใครรู้มากกว่านี้แวะมาบอกกันมั่งนะคะ