Femtosecond lasers versus phacoemulsification technology

The ultimate goal of laser refractive cataract surgery is to give the patient a premium surgical experience

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Although femtosecond lasers have proven their utility in cataract surgery, Zoltan Nagy MD, Chair of the Department of Ophthalmology, Semmelweis University, Budapest, Hungary, does not believe that they will completely supplant phacoemulsification technology. “I don’t think that femtosecond lasers will replace traditional phacoemulsification. However, femtosecond technology will ultimately replace the manually executed incision and capsulotomy steps in the cataract procedure and will effectively fragment the lens for more efficient lens removal. The ultimate goal of laser refractive cataract surgery is to give the patient a premium surgical experience and the surgeon a procedure to be performed with confidence and predictability,” said Dr Nagy. Using a femtosecond laser to perform cataract surgery increases the safety and efficacy of cataract removal and delivers more reliable and stable postoperative refractive outcomes compared to standard phacoemulsification, he said. “Femtosecond laser-assisted cataract surgery (FLACS) leads to safer and more efficient cataract removal. It enables more precise and reproducible capsulotomies and better intraocular lens (IOL) positioning, thereby providing better visual quality. It also results in reduced trauma to the cornea and macula, although further studies are needed to improve the outcomes through perioperative care,” he said. The typical profile of the patients presenting for femtosecond laser cataract surgery is not the same as for standard phacoemulsification procedures, Dr Nagy noted. “The femtosecond laser patient is usually younger and is happy to pay extra for the laser procedure. However, they are also more demanding as a result. They will often have gathered information from the Internet, which is not always accurate, and tend to undervalue the role of the physician. If something goes wrong, they will often be very quick to sue the doctor,” said Dr Nagy. In the face of such demanding patients, the best strategy of the doctor is to ensure that the patient is fully informed of the risks and benefits of the procedure. “Longer chair time is called for with these patients in order to present detailed information about the procedure and its possible complications. It is important to ensure that the patient signs all information and consent forms. The role of the doctor is to be professional and thorough and reassure the patient if they have particular concerns,” he said. The femtosecond laser effectively transforms key steps of the cataract procedure such as corneal incisions, capsulorhexis and lens fragmentation, said Dr Nagy. “With manual phaco, corneal incisions are not optimised and can result in astigmatism and infection. Likewise, the capsulorhexis size is variable and not centred, leading to erratic IOL position and effective lens power. Complications such as capsular tears and posterior capsule opacification (PCO) also pose a problem with manual continuous curvilinear capsulorhexis (CCC). Lens fragmentation is currently used with excessive ultrasound power and may result in delayed visual recovery, loss of endothelial cells and capsule rupture,” he said. By contrast, femtosecond laser enables more centred, circular and predictable capsulotomies, said Dr Nagy. “This results in better anterior capsule-IOL optic overlap and therefore a more predictable postoperative IOL position and better predictability of IOL power calculation. It also leads to more stable postoperative refraction, better optical quality and decreased PCO rates,” he said. Dr Nagy noted that several studies in the scientific literature have confirmed the superior centration and circularity of capsulotomies created by the femtosecond laser with a very low rate of complications. The postoperative quality of vision has also been found to be better after FLACS with less higher-order aberrations compared to standard phacoemulsification. More efficient lens fragmentation is another clear advantage of the femtosecond laser, said Dr Nagy. “It is better for lens fragmentation and efficiently fragments the lens for removal with reduced phaco time and power. There is also less increase of macular thickness after FLACS, perhaps due to the reduced phacoemulsification time,” he added. Zoltan Nagy: zoltan.nagy100@gmail.com