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106 EW FEATURE February 2011 Cataract/IOLs, femtosecond cataract March 2013 Update continued from page 104 manually, "but with the aid of a femtolaser, we can have more central incisions, have exact size and diameters every time, and we can guarantee that the edge of the IOL will be covered by 0.25 to 0.5 mm anterior capsule to provide better centration compared to manual surgery," Prof. Nagy said. For these experts, the ability of the femto to "improve the safety of surgery in challenging situations that have an increased risk of complications (i.e., mature cataract, dislocated lens, weak zonules, etc.)" is perhaps the most exciting, Dr. Friedman said. "Some data show that the refractive outcomes are slightly better due to a capsulotomy that perfectly overlaps the IOL optic keeping it closer to the predicted effective lens placement." Prof. Nagy's group2,3 "achieved better centration, less posterior capsule opacification (our results will be published shortly), predictable geometry of corneal wounds, less endothelial stress and damage, and possibly less cystoid macular edema," he said. The potential to improve safety "is incremental because any of the potential complications are still very rare," Dr. Friedman said. Tens of thousands of cases—maybe hundreds of thousands—will need to be performed with these technologies before a true claim of complication reduction can be made, he said. Dr. Culbertson believes the femtolaser will inevitably lead to fewer cases of endophthalmitis "because the wounds don't leak," but also said more than 100,000 cases will need to be performed to show any true advantage. When the lens is broken up via laser instead of manually, "it's a little less likely to rip in the bag," Dr. Endl said, adding that, too, is a rare occurrence. Cases that used to be difficult with phaco—such as shallow anterior chambers—are not as problematic "because the in-built optical coherence tomography controls the anatomy of the eye, and surgeons can avoid hitting the endothelial cell layer," Prof. Nagy explained. "In zonular dehiscence, femtolaser is a great advantage because we eliminate the zonular stress, and the SoftFit patient interface [Alcon, Fort Worth, Texas] can compensate for lens tilt." Key attributes and drawbacks A typical healthy LASIK patient can expect postop uncorrected vision of 20/20 upward of 95% of the time. Until recently, however, Dr. Endl said even the best cataract surgeons may achieve this outcome only 70% of the time. "The femto laser will look to make cataract surgery outcomes more precise and predictable," he said. With acknowledged downsides of the technology being both the cost and the additional surgical time, the reproducibility "allows more surgeons and patients to ultimately benefit," Dr. Friedman said. "If cost/reimbursement issues and time were not an issue, femto would immediately become the preferred method of cataract surgery." Prof. Nagy said there is a "promise for colleagues and patients that the benefits of the advanced technology IOLs can be better used if a femtolaser is incorporated into the ophthalmic practice." Dr. Endl said one difficulty with integrating the new technology is patient flow and trying to minimize the number of stops a patient has to make, but his patients have readily accepted the slight inconvenience. Patient particulars Not every patient is a candidate for the femtolaser, these experts warned. For instance, patients with small pupils (<6.5 mm) or significant corneal opacities are not ideal. Dr. Endl agreed, saying the technology has helped ease some of his fear in more difficult cases (the laser Managing continued from page 102 rations," he said. Ironically, these are often the same patients who are interested in presbyopia-correcting IOLs in the first place, so he may consider an accommodating IOL as an option in these cases, Dr. Kim said. EW Editors' note: Drs. Berdahl has financial interests with Alcon (Fort Worth, Texas). Dr. Kim has financial interests with Alcon and Bausch + Lomb (Rochester, N.Y.). The other physicians have no financial interests related to their comments. Contact information Berdahl: 605-328-3937, johnberdahl@gmail.com Black: 812-284-0660, drbradblack@aol.com Dhaliwal: 412-647-2257, dhaliwaldk@upmc.edu Kim: 919-681-3568, terry.kim@duke.edu "doesn't care if it's a white cataract— it'll put the circle anywhere you want it to go"), but none of the surgeons said the technology is without any potential complications. Dr. Friedman said complications associated with the femtolaser are incomplete capsulotomy, a substantial increase in intraocular pressure during the procedure, or subconjunctival hemorrhage, "but that differs among the various devices." A partial capsulotomy "may account for anterior capsular tears," but surgeons should follow the contour of the capsulotomy during their learning curves to minimize the issue, Prof. Nagy said. "Capsular blockage syndrome can also be avoided if the surgeon is using the so called 'rock-and-roll' technique: gentle hydrodissection and push down a bit and move the lens (rock and roll), then the gas bubble is allowed to leave toward the anterior chamber, not causing blockage syndrome," Prof. Nagy said. Avoiding the conjunctival vessels during wound creation will avoid the potential for an incomplete corneal cut, he said. Ideally, Prof. Nagy said, he'd like to see a femtolaser "with multifunctional use: cataract, corneal surgery, possibly glaucoma control, and maybe vitreoretinal use. I do not know whether it can come true, we will see it. But without a vision, no development is possible." Perhaps Juan Battle, M.D., said it best during last year's ESCRS conference: "The femtosecond laser in cataract surgery makes normal cases easier, tough or difficult cases like normal cases, and impossible cases possible," Dr. Culbertson said. Mobile femto services In the U.S., SightPath Medical (Minneapolis) is the first company to mobilize the femtolaser, and the company says as few as six cases a month will create profit for a center. Dr. Friedman said "it's a great service because it's going to allow more surgeons and more patients to benefit from the technology," and Dr. Culbertson said SightPath had similar success with a mobile excimer laser (Alcon's platform), so there is potential for surgeons who are interested in the technology but do not find it feasible to purchase on their own. EW References 1. Conrad-Hengerer I, Hengerer FH, Schultz T, Dick HB. Effect of femtosecond laser fragmentation of the nucleus with different softening grid sizes on effective phaco time in cataract surgery. J Cataract Refract Surg. 2012;38:1888-1894. 2. Nagy ZZ, Kranitz K, Takacs AI, Mihaltz K, Kovacs I, Knorz MC. Comparison of intraocular lens decentration parameters after femtosecond and manual capsulotomies. J Refract Surg. 2011;27:564-569. 3. Kranitz K, Takacs A, Mihalta K, Kovacs I, Knorz MC, Nagy ZZ. Femtosecond laser capsulotomy and manual continuous curvilinear capsulorhexis parameters and their effects on intraocular lens centration. J Refract Surg. 2011;27:558-563. Additional suggested reading 1. Friedman NJ, Palanker DV, Schuele G, et al. Femtosecond laser capsulotomy. J Cataract Refract Surg. 2011; 37:1189-1198. 2. He L, Sheehy K, Culbertson W. Femtosecond laser-assisted cataract surgery. Curr Opin Ophthalmol. 2011;22:43–52. 3. Palanker DV, Blumenkranz MS, Andersen D, et al. Femtosecond laser-assisted cataract surgery with integrated optical coherence tomography. Sci Transl Med. 2010;2:58ra85. Editors' note: Dr. Culbertson has financial interests with OptiMedica (Sunnyvale, Calif.). Dr. Endl has financial interests with Alcon, Bausch + Lomb (Rochester, N.Y.), Merck (Whitehouse Station, N.J.), and Refocus Group (Dallas). Dr. Friedman has financial interests with OptiMedica. Dr. Nagy has financial interests with Alcon. Contact information Culbertson: w.culbertson@miami.edu Endl: mpderme@aol.com Friedman: njfmd@ymail.com Nagy: nagy.zoltan_zsolt@med.semmelweis-univ.hu EyeWorld @EWNews Keep up on the latest in ophthalmology! Follow EyeWorld on Twitter at twitter.com/EWNews