A new approach to cataract surgery using a special femtosecond laser may be safer and more efficient than the standard procedure available today, according to two recent studies. The approach is FDA-approved, but not yet widely available in the U.S.
A research team led by William W. Culbertson, MD, of the Bascom Palmer Eye Institute at the University of Miami School of Medicine (Miami, FL) studied how pre-treating cataracts with the femtosecond laser affected the level of ultrasound energy needed to soften the cataracts. This emulsification is performed so that the cataracts can be easily suctioned out. Surgeons want to use the lowest possible level of ultrasound energy, since in a small percentage of patients it is associated with slower recovery of good vision after surgery and/or problems with the cornea, which is the clear outer layer of the eye. Ideally, in appropriate cases, ultrasound use would be eliminated altogether.
In the randomized study, 29 patients had laser cataract surgery with a femtosecond laser in one eye and the standard cataract procedure, called phacoemulsification, in the other. Laser surgery included a laser capsulotomy, which is a circular incision in the lens capsule, followed by laser lens fragmentation, ultrasound emulsification and aspiration. Lens fragmentation involved using the laser to split the lens into sections and then soften it by etching cross-hatch patterns on its surface. Standard surgery included a manual incision, followed by ultrasound emulsification and aspiration. After cataract removal by either method, intraocular lenses were inserted into eyes to replace the natural lens and provide appropriate vision correction for each patient.
The use of ultrasound energy use was reduced by 45 percent in the laser pre-treated eyes compared with the eyes that received the standard cataract surgery procedure. Also, surgical manipulation of the eye was reduced by 45 percent in eyes that received laser pre-treatment as compared to manual standard surgery. This study involved the most common types of cataracts, those graded 1–4. Dr. Culbertson notes that these findings may not apply to higher grade cataracts.
Mark Packer, MD, of Oregon Health and Sciences University (Portland, OR) assessed the safety of laser cataract surgery in terms of loss of corneal endothelial cells, as measured after cataract surgery. Measuring endothelial cell loss is one of the most important ways to assess the safety of new cataract surgery techniques and technology. These cells preserve the cornea’s clarity, and since they don’t regenerate, they must last a lifetime. Dr. Packer’s study found that when laser lens fragmentation was used in 225 eyes, there was no loss of endothelial cells, while the 63 eyes that received standard treatment had cell loss of one to seven percent.
Earlier studies of femtosecond laser cataract surgery found other benefits. The laser allows the surgeon to make smaller, more precise incisions and to perform improved capsulotomies, which is the removal of part of the lens capsule that make intraocular lens (IOL) placement more secure. This reduces the chance that an IOL will later become displaced. Also, laser cataract surgery appears to improve results in patients who opt for advanced technology IOLs, plus corrective corneal incisions, to achieve good all-distance vision.
Femtosecond cataract laser surgery is among the hottest topics at the 115th Annual Meeting of the American Academy of Ophthalmology, being held October 23–25 at the Orange County Convention Center in Orlando, FL. The meeting features Dr. Culbertson’s and Dr. Packer’s presentations, as well as key sessions on the topic, including Spotlight on Femtosecond-Assisted Cataract Surgery: The Tough Questions; Femtosecond Laser Cataract Surgery: The Future; a video presentation; and two new instruction courses.
For more information, please visit http://www.aao.org/meetings/annual_meeting/program/index.cfm.
Follow us on Twitter, 'like' us on Facebook, and join our group on LinkedIn
Follow OptoIQ on your iPhone; download the free app here.
Subscribe now to BioOptics World magazine; it's free!